"""Main GUI window for Zynq XC7Z100 Flasher.

Integrates all backend modules into a modern, step-by-step workflow GUI
built with CustomTkinter.
"""

from __future__ import annotations

import os
import threading
import time
import tkinter as tk
from pathlib import Path
from typing import Callable

import customtkinter as ctk

from config_manager import Config
from vitis_checker import check_vitis, get_tool_status_dict
from zynq_checker import check_zynq_jtag, get_zynq_status_dict
from flash_programmer import full_flash_program, FlashResult
from bitstream_programmer import full_bitstream_program, BitstreamResult
from ip_verifier import ping_ip
from tftp_manager import tftp_upload_verify, TftpResult
from reboot_manager import reboot_zynq, RebootResult
from boot_verifier import verify_boot, verify_zynq_status, BootVerificationResult
from serial_monitor import detect_serial_ports, parse_boot_output, check_uart_available, UartMonitor
from gui.styles import (
    WINDOW_WIDTH,
    WINDOW_HEIGHT,
    WINDOW_TITLE,
    FONT_TITLE,
    FONT_HEADING,
    FONT_BODY,
    FONT_SMALL,
    FONT_MONO,
    PADDING,
    PADDING_LARGE,
    PADDING_SMALL,
    CORNER_RADIUS,
    PRIMARY_COLOR,
    SUCCESS_COLOR,
    WARNING_COLOR,
    DANGER_COLOR,
    INFO_COLOR,
    CONNECTOR_COLOR,
    get_theme,
)
from gui.widgets import (
    StepHeader,
    ProgressIndicator,
    StatusDisplay,
    FileSelector,
    LogDisplay,
    SubStepFrame,
)


class MainWindow(ctk.CTk):
    """Main application window for Zynq Flasher GUI."""

    def __init__(self) -> None:
        """Initialize the main window."""
        super().__init__()

        self.title(WINDOW_TITLE)
        self.geometry(f"{WINDOW_WIDTH}x{WINDOW_HEIGHT}")
        self.minsize(800, 600)

        ctk.set_appearance_mode("dark")
        ctk.set_default_color_theme("blue")

        self._config: Config | None = None
        self._config_path = self._find_config()
        self._steps: list[StepHeader] = []
        self._step_statuses: dict[int, str] = {}
        self._is_running = False
        self._worker_thread: threading.Thread | None = None
        self._uart_available: bool = False
        self._uart_message: str = ""
        self._zynq_jtag_present: bool = False
        self._zynq_jtag_info = None
        self._uart_monitor: UartMonitor | None = None
        self._flash_phase: str = ""

        # StringVar references for config sync
        self._ip_string_var: ctk.StringVar | None = None

        self._load_config()
        self._build_ui()
        self._update_step_dependencies()

        # Handle window close
        self.protocol("WM_DELETE_WINDOW", self._on_close)

        # Defer blocking operations until after the window is displayed
        self.after(100, self._deferred_init)

    def _deferred_init(self) -> None:
        """Run blocking operations in background thread after window shown."""
        def _bg_init():
            self._check_vitis()
            self._refresh_ports_initial()
        threading.Thread(target=_bg_init, daemon=True).start()

    # ── Config ─────────────────────────────────────────────────

    def _find_config(self) -> Path | None:
        """Find the user configuration file.

        Checks common locations:
        1. config.yaml (project root, user's config)
        2. config/default_config.yaml (template, not for saving)
        3. User-specified path via env var

        Returns:
            Path to user config file, or None if not found.
        """
        # Navigate from src/gui/main_window.py -> project root
        app_dir = Path(__file__).parent.parent.parent

        # 1. Check for user config at project root
        user_config = app_dir / "config.yaml"
        if user_config.exists():
            return user_config

        # 2. Check for default config (template)
        config_dir = app_dir / "config"
        default_config = config_dir / "default_config.yaml"
        if default_config.exists():
            return default_config

        # 3. Check env var
        env_path = os.environ.get("ZYNQ_CONFIG")
        if env_path:
            return Path(env_path)

        return None

    def _get_user_config_path(self) -> Path:
        """Get the path to the user config file (config.yaml).

        Creates config.yaml in project root if it doesn't exist.

        Returns:
            Path to user config file.
        """
        # Navigate from src/gui/main_window.py -> project root
        app_dir = Path(__file__).parent.parent.parent
        config_path = app_dir / "config.yaml"
        config_path.parent.mkdir(parents=True, exist_ok=True)
        return config_path

    def _load_config(self) -> None:
        """Load configuration from file or create default."""
        if self._config_path:
            try:
                self._config = Config.from_file(self._config_path)
                # If loaded from default_config.yaml, set save path to config.yaml
                if self._config_path.name == "default_config.yaml":
                    user_config_path = self._get_user_config_path()
                    self._config._config_path = user_config_path
            except Exception:
                self._config = Config.from_default()
                # Set save path to config.yaml for new configs
                user_config_path = self._get_user_config_path()
                self._config._config_path = user_config_path
        else:
            self._config = Config.from_default()
            # Set save path to config.yaml for new configs
            user_config_path = self._get_user_config_path()
            self._config._config_path = user_config_path

    def _sync_config_from_ui(self) -> None:
        """Read current UI values and update the Config object.

        This must be called before _save_config() to ensure
        the Config object has the latest UI values.
        """
        if not self._config:
            return
        # Sync IP address
        if self._ip_string_var:
            self._config.zynq_ip = self._ip_string_var.get()
        # Sync serial port
        self._config.serial_port = self._port_var.get()
        # Sync file paths from FileSelectors
        files = self._get_selected_files()
        self._config.bootloader_bit_path = files["bootloader_bit_path"]
        self._config.bootloader_elf_path = files["bootloader_elf_path"]
        self._config.bootloader_bin_path = files["bootloader_bin_path"]
        self._config.fsbl_elf_path = files["fsbl_elf_path"]
        self._config.erase_all = self._erase_cb_var.get()
        self._config.firmware_bin_path = files["firmware_bin_path"]

    def _save_config(self) -> None:
        """Save current configuration to user config file (config.yaml).

        Always saves to config/config.yaml, not to default_config.yaml.
        """
        self._sync_config_from_ui()  # Sync UI values first
        if not self._config:
            self._log_message("  No config loaded")
            return

        # Save to user config file (config.yaml)
        user_config_path = self._get_user_config_path()
        self._config._config_path = user_config_path  # Set save path
        try:
            self._config.save()
            self._log_message(f"  Config saved to {user_config_path}")
            self._status.set_status("Config saved", "success")
        except Exception as e:
            self._log_message(f"  ✗ Save failed: {e}")
            self._status.set_status(f"Save failed: {e}", "error")

    def _on_erase_toggle(self) -> None:
        """Update config.erase_all immediately when checkbox toggles."""
        if self._config:
            self._config.erase_all = self._erase_cb_var.get()

    # ── UI Construction ────────────────────────────────────────

    def _build_ui(self) -> None:
        """Build the complete UI layout."""
        # Main container with padding
        main_frame = ctk.CTkFrame(self)
        main_frame.pack(fill="both", expand=True, padx=PADDING_LARGE, pady=PADDING_LARGE)
        main_frame.grid_rowconfigure(1, weight=1)
        main_frame.grid_columnconfigure(0, weight=1)

        # ── Header ──
        self._build_header(main_frame)

        # ── Left Panel: Workflow Steps ──
        left_frame = ctk.CTkFrame(main_frame)
        left_frame.grid(row=1, column=0, sticky="nsew", padx=(0, PADDING))
        left_frame.grid_rowconfigure(3, weight=1)
        left_frame.grid_columnconfigure(0, weight=1)

        self._build_workflow_panel(left_frame)
        self._build_log_panel(left_frame)

        # ── Right Panel: Configuration ──
        right_frame = ctk.CTkFrame(main_frame)
        right_frame.grid(row=1, column=1, sticky="nsew", padx=(PADDING, 0))
        right_frame.grid_rowconfigure(4, weight=1)

        self._build_config_panel(right_frame)
        self._build_serial_panel(right_frame)
        self._build_status_panel(right_frame)

    def _build_header(self, parent: ctk.CTkFrame) -> None:
        """Build the application header."""
        header = ctk.CTkFrame(parent, corner_radius=CORNER_RADIUS)
        header.grid(row=0, column=0, columnspan=2, sticky="nsew", pady=(0, PADDING))
        header.grid_columnconfigure(1, weight=1)

        title = ctk.CTkLabel(
            header,
            text="Zynq XC7Z100 Flasher",
            font=FONT_TITLE,
        )
        title.grid(row=0, column=0, padx=PADDING, pady=PADDING)

        self._vitis_status = ctk.CTkLabel(
            header,
            text="Vitis: Checking...",
            font=FONT_BODY,
        )
        self._vitis_status.grid(row=0, column=1, sticky="e", padx=PADDING)

        self._ip_status = ctk.CTkLabel(
            header,
            text=f"IP: {self._config.zynq_ip}",
            font=FONT_BODY,
        )
        self._ip_status.grid(row=0, column=2, sticky="e", padx=PADDING)

        self._jtag_status = ctk.CTkLabel(
            header,
            text="JTAG: Checking...",
            font=FONT_BODY,
        )
        self._jtag_status.grid(row=0, column=3, sticky="e", padx=PADDING)

    def _build_workflow_panel(self, parent: ctk.CTkFrame) -> None:
        """Build the step-by-step workflow panel."""
        panel = ctk.CTkFrame(parent, corner_radius=CORNER_RADIUS)
        panel.grid(
            row=0, column=0, sticky="nsew",
            padx=PADDING, pady=(PADDING, 0),
        )
        panel.grid_rowconfigure(10, weight=1)
        panel.grid_columnconfigure(0, weight=1)

        # ── Title ──
        title = ctk.CTkLabel(
            panel,
            text="Workflow",
            font=FONT_HEADING,
        )
        title.grid(row=0, column=0, padx=PADDING_SMALL, pady=(PADDING_SMALL, PADDING_SMALL))

        # ── Steps ──
        step_defs = [
            {"num": 1, "title": "Check Environment", "desc": "Verify tools & connectivity"},
            {"num": 2, "title": "Program & Verify Flash", "desc": "Wipe, program, and verify flash"},
            {"num": 3, "title": "Load Bootloader", "desc": "Program BIT + run ELF"},
            {"num": 4, "title": "Load Main Program", "desc": "TFTP upload, reboot, verify boot"},
        ]

        self._steps = []
        self._step_statuses = {}
        for i, defn in enumerate(step_defs):
            step = StepHeader(
                panel,
                step_number=defn["num"],
                title=defn["title"],
                description=defn["desc"],
                callback=lambda idx=i: self._execute_step(idx),
                can_run=(i == 0),
            )
            self._steps.append(step)
            self._step_statuses[i] = "pending"

            # Divider line between steps
            if i > 0:
                divider = ctk.CTkFrame(
                    panel,
                    height=1,
                    fg_color=CONNECTOR_COLOR,
                )
                divider.grid(
                    row=i * 2, column=0,
                    sticky="ew",
                    padx=PADDING,
                    pady=(2, 0),
                )

            # Position step
            step.grid(
                row=i * 2 + 1, column=0,
                sticky="nsew",
                padx=PADDING_SMALL,
                pady=(0, 2),
            )

            # Step 2: add collapsible sub-step frame
            if i == 1:
                self._sub_step_frame = SubStepFrame(panel)
                self._sub_step_frame.grid(
                    row=i * 2 + 2, column=0,
                    sticky="nsew",
                    padx=PADDING_SMALL + 16,
                    pady=(0, 2),
                )

        # ── Progress indicator ──
        self._progress = ProgressIndicator(panel)
        self._progress.grid(
            row=8, column=0,
            sticky="nsew",
            padx=PADDING,
            pady=(PADDING, PADDING_SMALL),
        )

        # ── Run All button ──
        self._run_btn = ctk.CTkButton(
            panel,
            text="▶ Run All Steps",
            font=FONT_HEADING,
            command=self._run_all_steps,
            height=40,
            corner_radius=CORNER_RADIUS,
        )
        self._run_btn.grid(
            row=9, column=0,
            sticky="nsew",
            padx=PADDING,
            pady=PADDING_SMALL,
        )

    def _build_log_panel(self, parent: ctk.CTkFrame) -> None:
        """Build the log display panel."""
        panel = ctk.CTkFrame(parent, corner_radius=CORNER_RADIUS)
        panel.grid(
            row=1, column=0, sticky="nsew",
            padx=PADDING, pady=PADDING,
        )
        panel.grid_rowconfigure(1, weight=1)
        panel.grid_columnconfigure(0, weight=1)

        title = ctk.CTkLabel(
            panel,
            text="Log",
            font=FONT_HEADING,
        )
        title.grid(row=0, column=0, padx=PADDING, pady=PADDING)

        self._log_display = LogDisplay(panel, height=250)
        self._log_display.grid(row=1, column=0, sticky="nsew", padx=PADDING, pady=PADDING)

        # Clear button
        clear_btn = ctk.CTkButton(
            panel,
            text="Clear Log",
            font=FONT_SMALL,
            command=self._log_display.clear,
            width=100,
        )
        clear_btn.grid(row=0, column=1, padx=PADDING, pady=PADDING)

    def _build_config_panel(self, parent: ctk.CTkFrame) -> None:
        """Build the configuration panel."""
        panel = ctk.CTkFrame(parent, corner_radius=CORNER_RADIUS)
        panel.grid(
            row=0, column=0, sticky="nsew",
            padx=PADDING, pady=PADDING,
        )
        panel.grid_rowconfigure(7, weight=1)

        title = ctk.CTkLabel(
            panel,
            text="Configuration",
            font=FONT_HEADING,
        )
        title.grid(row=0, column=0, padx=PADDING, pady=PADDING)

        # IP address
        ip_frame = ctk.CTkFrame(panel)
        ip_frame.grid(row=1, column=0, sticky="nsew", padx=PADDING, pady=PADDING_SMALL)
        ip_frame.grid_columnconfigure(1, weight=1)

        ctk.CTkLabel(ip_frame, text="Zynq IP:", font=FONT_BODY).grid(row=0, column=0, sticky="w")
        self._ip_string_var = ctk.StringVar(value=self._config.zynq_ip)
        self._ip_entry = ctk.CTkEntry(ip_frame, textvariable=self._ip_string_var)
        self._ip_entry.grid(row=0, column=1, sticky="nsew", padx=PADDING_SMALL)

        # BIT path (Bootloader)
        self._bit_selector = FileSelector(
            panel,
            label_text="Bootloader BIT (.bit):",
            file_types=[("BIT files", "*.bit"), ("All files", "*")],
        )
        if self._config.bootloader_bit_path:
            resolved = self._config.resolve_path(self._config.bootloader_bit_path)
            self._bit_selector.set_path(str(resolved))
        self._bit_selector.grid(row=2, column=0, sticky="nsew", padx=PADDING, pady=PADDING_SMALL)

        # ELF path (Bootloader)
        self._elf_selector = FileSelector(
            panel,
            label_text="Bootloader ELF (.elf):",
            file_types=[("ELF files", "*.elf"), ("All files", "*")],
        )
        if self._config.bootloader_elf_path:
            resolved = self._config.resolve_path(self._config.bootloader_elf_path)
            self._elf_selector.set_path(str(resolved))
        self._elf_selector.grid(row=3, column=0, sticky="nsew", padx=PADDING, pady=PADDING_SMALL)

        # Bootloader BIN path (Flash programming)
        self._bootloader_bin_selector = FileSelector(
            panel,
            label_text="Bootloader BIN (.bin):",
            file_types=[("BIN files", "*.bin"), ("All files", "*")],
        )
        if self._config.bootloader_bin_path:
            resolved = self._config.resolve_path(self._config.bootloader_bin_path)
            self._bootloader_bin_selector.set_path(str(resolved))
        self._bootloader_bin_selector.grid(row=4, column=0, sticky="nsew", padx=PADDING, pady=PADDING_SMALL)

        # FSBL ELF path (required by program_flash for QSPI programming)
        self._fsbl_selector = FileSelector(
            panel,
            label_text="FSBL ELF (.elf):",
            file_types=[("ELF files", "*.elf"), ("All files", "*")],
        )
        if self._config.fsbl_elf_path:
            resolved = self._config.resolve_path(self._config.fsbl_elf_path)
            self._fsbl_selector.set_path(str(resolved))
        self._fsbl_selector.grid(row=5, column=0, sticky="nsew", padx=PADDING, pady=PADDING_SMALL)

        # Flash options
        flash_frame = ctk.CTkFrame(panel)
        flash_frame.grid(row=6, column=0, sticky="nsew", padx=PADDING, pady=PADDING_SMALL)
        flash_frame.grid_columnconfigure(0, weight=1)

        self._erase_cb_var = ctk.BooleanVar(value=self._config.erase_all)
        self._erase_cb = ctk.CTkCheckBox(
            flash_frame,
            text="整片Flash擦除 (Erase entire flash)",
            variable=self._erase_cb_var,
            font=FONT_SMALL,
            command=self._on_erase_toggle,
        )
        self._erase_cb.grid(row=0, column=0, sticky="w", padx=PADDING_SMALL)

        flash_model_label = ctk.CTkLabel(
            flash_frame,
            text=f"Flash: {self._config.flash_model} (32 MiB)",
            font=FONT_SMALL,
        )
        flash_model_label.grid(row=1, column=0, sticky="w", padx=PADDING_SMALL, pady=(2, 0))

        # Firmware BIN path (TFTP upload)
        self._firmware_bin_selector = FileSelector(
            panel,
            label_text="Firmware BIN (.bin):",
            file_types=[("BIN files", "*.bin"), ("All files", "*")],
        )
        if self._config.firmware_bin_path:
            resolved = self._config.resolve_path(self._config.firmware_bin_path)
            self._firmware_bin_selector.set_path(str(resolved))
        self._firmware_bin_selector.grid(row=7, column=0, sticky="nsew", padx=PADDING, pady=PADDING_SMALL)

        # Save button
        save_btn = ctk.CTkButton(
            panel,
            text="Save Config",
            font=FONT_SMALL,
            command=self._save_config,
        )
        save_btn.grid(row=8, column=0, padx=PADDING, pady=PADDING)

    def _build_serial_panel(self, parent: ctk.CTkFrame) -> None:
        """Build the serial monitor panel."""
        panel = ctk.CTkFrame(parent, corner_radius=CORNER_RADIUS)
        panel.grid(
            row=1, column=0, sticky="nsew",
            padx=PADDING, pady=PADDING,
        )
        panel.grid_rowconfigure(3, weight=1)
        panel.grid_columnconfigure(0, weight=1)

        title = ctk.CTkLabel(
            panel,
            text="Serial Monitor",
            font=FONT_HEADING,
        )
        title.grid(row=0, column=0, padx=PADDING, pady=PADDING)

        # Port selector
        port_frame = ctk.CTkFrame(panel)
        port_frame.grid(row=1, column=0, sticky="nsew", padx=PADDING, pady=PADDING_SMALL)
        port_frame.grid_columnconfigure(1, weight=1)

        ctk.CTkLabel(port_frame, text="Port:", font=FONT_BODY).grid(row=0, column=0, sticky="w")
        self._port_var = ctk.StringVar(value=self._config.serial_port)
        self._port_menu = ctk.CTkComboBox(
            port_frame,
            values=[""] + [p.device for p in detect_serial_ports()],
            variable=self._port_var,
        )
        self._port_menu.grid(row=0, column=1, sticky="nsew", padx=PADDING_SMALL)

        # Refresh button
        refresh_btn = ctk.CTkButton(
            port_frame,
            text="Refresh",
            font=FONT_SMALL,
            command=self._refresh_ports,
            width=80,
        )
        refresh_btn.grid(row=0, column=2, padx=PADDING_SMALL)

        # Read button
        read_btn = ctk.CTkButton(
            panel,
            text="Read Serial",
            font=FONT_BODY,
            command=self._read_serial,
        )
        read_btn.grid(row=2, column=0, padx=PADDING, pady=PADDING_SMALL)

        # Test version button
        self._test_version_btn = ctk.CTkButton(
            panel,
            text="Test Version",
            font=FONT_BODY,
            command=self._test_serial_version,
        )
        self._test_version_btn.grid(row=3, column=0, padx=PADDING, pady=PADDING_SMALL)

    def _build_status_panel(self, parent: ctk.CTkFrame) -> None:
        """Build the status display panel."""
        panel = ctk.CTkFrame(parent, corner_radius=CORNER_RADIUS)
        panel.grid(
            row=2, column=0, sticky="nsew",
            padx=PADDING, pady=PADDING,
        )

        self._status = StatusDisplay(panel)
        self._status.pack(fill="x", padx=PADDING, pady=PADDING)

        # UART warning label (persistent, not overwritten by other status updates)
        self._uart_warning_label = ctk.CTkLabel(
            panel,
            text="",
            font=FONT_BODY,
            anchor="w",
            text_color=WARNING_COLOR,
        )
        self._uart_warning_label.pack(
            fill="x", padx=PADDING, pady=(0, PADDING_SMALL)
        )
        self._uart_warning_label.pack_forget()  # Hide by default

    # ── Workflow Steps ─────────────────────────────────────────

    def _log_message(self, message: str) -> None:
        """Append a message to the log display (thread-safe)."""
        self.after(0, lambda: self._log_display.append(message))

    def _set_step_status(self, index: int, status: str) -> None:
        """Set the status of a workflow step.

        Args:
            index: Step index (0-based).
            status: Status string ('pending', 'running', 'complete', 'error').
        """
        if 0 <= index < len(self._steps):
            self._steps[index].set_status(status)

    def _get_selected_files(self) -> dict:
        """Get selected file paths from the UI.

        Returns:
            Dictionary with all file paths from UI selectors.
        """
        return {
            "bootloader_bit_path": self._bit_selector.get_path(),
            "bootloader_elf_path": self._elf_selector.get_path(),
            "bootloader_bin_path": self._bootloader_bin_selector.get_path(),
            "fsbl_elf_path": self._fsbl_selector.get_path(),
            "firmware_bin_path": self._firmware_bin_selector.get_path(),
        }

    # ── Step Implementations ───────────────────────────────────

    def _run_step_1_check_environment(self) -> bool:
        """Step 1: Check environment (Vitis/Vivado tools + Zynq IP + UART)."""
        self._log_message("Step 1: Checking environment...")

        if not self._config:
            self._log_message("  No config loaded")
            return False

        # Check Vitis/Vivado tools
        self._log_message("  Checking Vitis/Vivado tools...")
        result = check_vitis(self._config)
        status_dict = get_tool_status_dict(result)

        for tool_name, tool_info in status_dict["tools"].items():
            if tool_info["found"]:
                alias_note = f" (via {tool_info['alias']})" if tool_info.get("alias") and tool_info["alias"] != tool_name else ""
                self._log_message(f"    ✓ {tool_name}: {tool_info['path']}{alias_note}")
            else:
                self._log_message(f"    ✗ {tool_name}: {tool_info['error']}")

        if result.is_ready:
            self._vitis_status.configure(text="Vitis: Ready", text_color=SUCCESS_COLOR)
            self._log_message("  Vitis/Vivado tools available")
        else:
            self._vitis_status.configure(text="Vitis: Partial", text_color=WARNING_COLOR)
            self._log_message(f"  Issues: {'; '.join(result.errors)}")

        # Check Zynq JTAG presence
        self._log_message("  Checking Zynq JTAG presence...")
        jtag_result = check_zynq_jtag(self._config, self._jtag_callback)
        jtag_dict = get_zynq_status_dict(jtag_result)

        # Log JTAG chain information
        if jtag_result.jtag_chain:
            self._log_message(f"  JTAG chain: {len(jtag_result.jtag_chain)} device(s)")
            for jtag_dev in jtag_result.jtag_chain:
                dev_type = "ARM DAP (PS)" if jtag_dev.is_arm_dap else "PL" if jtag_dev.is_pl_device else "Other"
                self._log_message(f"    - {jtag_dev.name} ({dev_type})")

        if jtag_result.is_present:
            self._zynq_jtag_present = True
            self._zynq_jtag_info = jtag_result.devices[0]
            part = jtag_result.devices[0].part_number

            # Log PS and PL detection status
            ps_status = "✓" if jtag_result.ps_detected else "✗"
            pl_status = "✓" if jtag_result.pl_detected else "✗"
            self._log_message(f"  PS (ARM DAP): {ps_status}")
            self._log_message(f"  PL: {pl_status}")

            self._log_message(f"  ✓ Zynq {part} detected on JTAG chain")
            self._jtag_status.configure(text=f"JTAG: {part} ✓", text_color=SUCCESS_COLOR)
        else:
            self._zynq_jtag_present = False
            self._zynq_jtag_info = None
            self._log_message(f"  ✗ Zynq not detected on JTAG: {jtag_result.error}")
            self._jtag_status.configure(text="JTAG: Not detected", text_color=WARNING_COLOR)

        # Check UART availability
        self._log_message("  Checking UART serial port...")
        port = self._config.serial_port
        if port:
            available, reason = check_uart_available(port, self._config.serial_baudrate)
            self._uart_available = available
            self._uart_message = reason
            if available:
                self._log_message(f"  ✓ UART available: {reason}")
            else:
                self._log_message(f"  ✗ UART unavailable: {reason}")
                self._show_uart_notification(reason)
        else:
            self._uart_available = False
            self._uart_message = "No serial port configured"
            self._log_message("  ✗ No serial port configured")
            self._show_uart_notification(self._uart_message)

        return True

    def _show_uart_notification(self, reason: str) -> None:
        """Show a persistent UART unavailable notification.

        This notification stays visible and is not overwritten by other status updates.

        Args:
            reason: Why UART is unavailable.
        """
        msg = f"⚠ UART 不可用 ({reason})，日志分析及检查将禁用"
        self.after(0, lambda: self._show_uart_warning(msg))

    def _show_uart_warning(self, msg: str) -> None:
        """Display the persistent UART warning message.

        Args:
            msg: Warning message to display.
        """
        self._uart_warning_label.configure(text=msg)
        self._uart_warning_label.pack(fill="x", padx=PADDING, pady=(0, PADDING_SMALL))

    def _run_step_2_program_flash(self) -> bool:
        """Step 2: Program and verify Flash using program_flash."""
        if not self._config:
            return False

        files = self._get_selected_files()
        if not files["bootloader_bin_path"]:
            self._log_message("  No Bootloader BIN file selected")
            return False

        if not files["fsbl_elf_path"]:
            self._log_message("  No FSBL ELF file selected (required by program_flash)")
            return False

        self._log_message(f"Step 2: Programming Flash with {files['bootloader_bin_path']}...")
        self._log_message(f"  FSBL: {files['fsbl_elf_path']}")

        try:
            bin_path = Path(files["bootloader_bin_path"])
            results = full_flash_program(self._config, bin_path, self._flash_callback)

            for result in results:
                status = "✓" if result.success else "✗"
                self._log_message(f"  {status} {result.step}: {result.message}")

            return all(r.success for r in results)
        except Exception as e:
            self._log_message(f"  ✗ Flash error: {e}")
            return False

    def _flash_callback(self, status: str, message: str) -> None:
        """Callback for flash programming — drives sub-step UI."""
        if status == "phase":
            self._flash_phase = message
            phase_names = {"erase": "Erasing", "program": "Programming", "verify": "Verifying", "done": "Done"}
            label = phase_names.get(message, message)
            self._log_message(f"  ▸ {label}")
            if hasattr(self, '_sub_step_frame'):
                self._sub_step_frame.set_phase(message)
            return
        if status == "progress":
            try:
                pct = int(message.rstrip('%'))
            except ValueError:
                pct = -1
            phase_label = {"erase": "Erase", "program": "Program", "verify": "Verify"}.get(
                self._flash_phase, "Flash")
            self._log_message(f"  [{phase_label}] {pct}%")
            if hasattr(self, '_sub_step_frame'):
                self._sub_step_frame.set_phase(self._flash_phase, pct)
            return
        self._log_message(f"  [{status}] {message}")

    def _jtag_callback(self, status: str, message: str) -> None:
        """Callback for JTAG scan progress."""
        self._log_message(f"  [{status}] {message}")

    def _run_step_3_load_bootloader(self) -> bool:
        """Step 3: Load bootloader (BIT + ELF) and verify."""
        if not self._config:
            return False

        files = self._get_selected_files()
        if not files["bootloader_bit_path"]:
            self._log_message("  No Bootloader BIT file selected")
            return False

        self._log_message(f"Step 3: Loading bootloader (BIT + ELF)...")
        self._log_message(f"  BIT: {files['bootloader_bit_path']}")
        if files["bootloader_elf_path"]:
            self._log_message(f"  ELF: {files['bootloader_elf_path']}")

        try:
            bit_path = Path(files["bootloader_bit_path"])
            elf_path = Path(files["bootloader_elf_path"]) if files["bootloader_elf_path"] else bit_path.parent / "temp.elf"

            results = full_bitstream_program(
                self._config, bit_path, elf_path,
                self._bitstream_callback,
            )

            for result in results:
                status = "✓" if result.success else "✗"
                self._log_message(f"  {status} {result.step}: {result.message}")

            return all(r.success for r in results)
        except Exception as e:
            self._log_message(f"  ✗ Bootloader error: {e}")
            return False

    def _bitstream_callback(self, status: str, message: str) -> None:
        """Callback for bitstream programming progress."""
        self._log_message(f"  [{status}] {message}")

    def _run_step_4_load_main_program(self) -> bool:
        """Step 4: Load main program (TFTP upload + reboot + boot verify)."""
        if not self._config:
            return False

        files = self._get_selected_files()
        if not files["firmware_bin_path"]:
            self._log_message("  No Firmware BIN file selected")
            return False

        all_results: list[bool] = []

        # 4a: TFTP upload
        self._log_message("Step 4a: TFTP upload & verify...")
        try:
            bin_path = Path(files["firmware_bin_path"])
            tftp_result = tftp_upload_verify(
                self._config, bin_path,
                callback=self._tftp_callback,
            )
            status = "✓" if tftp_result.success else "✗"
            self._log_message(f"  {status} {tftp_result.message}")
            all_results.append(tftp_result.success)
        except Exception as e:
            self._log_message(f"  ✗ TFTP error: {e}")
            all_results.append(False)

        if not all_results[-1]:
            self._log_message("  Skipping reboot & boot verify (TFTP failed)")
            return False

        # 4a2: Post-download Zynq status check
        self._log_message("Step 4b: Checking Zynq status after download...")
        try:
            zynq_status = verify_zynq_status(
                self._config,
                uart_available=self._uart_available,
                callback=self._zynq_status_callback,
            )
            status = "✓" if zynq_status.success else "✗"
            self._log_message(f"  {status} {zynq_status.message}")
        except Exception as e:
            self._log_message(f"  ✗ Zynq status check error: {e}")

        # 4c: Reboot
        self._log_message("Step 4c: Rebooting Zynq...")
        try:
            reboot_result = reboot_zynq(
                self._config,
                method="auto",
                callback=self._reboot_callback,
            )
            status = "✓" if reboot_result.success else "✗"
            self._log_message(f"  {status} {reboot_result.message}")
            all_results.append(reboot_result.success)
        except Exception as e:
            self._log_message(f"  ✗ Reboot error: {e}")
            all_results.append(False)

        if not all_results[-1]:
            self._log_message("  Skipping boot verify (reboot failed)")
            return False

        # 4d: Verify boot
        self._log_message("Step 4d: Verifying boot...")
        try:
            boot_result = verify_boot(
                self._config,
                callback=self._boot_callback,
            )
            status = "✓" if boot_result.success else "✗"
            self._log_message(f"  {status} {boot_result.message}")

            if boot_result.ip_reachable:
                self._log_message(f"  IP {self._config.zynq_ip} is reachable")
            if boot_result.serial_found:
                self._log_message(f"  Boot info: {boot_result.boot_info}")

            all_results.append(boot_result.success)
        except Exception as e:
            self._log_message(f"  ✗ Boot verify error: {e}")
            all_results.append(False)

        return all(all_results)

    def _tftp_callback(self, status: str, message: str) -> None:
        """Callback for TFTP progress."""
        self._log_message(f"  [{status}] {message}")

    def _reboot_callback(self, status: str, message: str) -> None:
        """Callback for reboot progress."""
        self._log_message(f"  [{status}] {message}")

    def _boot_callback(self, status: str, message: str) -> None:
        """Callback for boot verification progress."""
        self._log_message(f"  [{status}] {message}")

    def _zynq_status_callback(self, status: str, message: str) -> None:
        """Callback for post-download Zynq status check."""
        self._log_message(f"  [{status}] {message}")

    # ── Run All Steps ──────────────────────────────────────────

    def _update_step_dependencies(self) -> None:
        """Update step run-ability based on dependency status.

        All steps are runnable independently.
        """
        for i, step in enumerate(self._steps):
            step.set_can_run(True)
            status = self._step_statuses.get(i, "pending")
            if status == "pending":
                step.set_status("pending")
            elif status == "complete":
                step.set_status("complete")
            elif status == "error":
                step.set_status("error")

    def _execute_step(self, index: int) -> None:
        """Execute a single step independently.

        Args:
            index: Step index (0-based).
        """
        if self._is_running:
            return

        if index >= len(self._steps):
            return

        self._is_running = True
        self._run_btn.configure(state="disabled", text="Running...")
        self._progress.reset()

        # Reset status for this step only
        self._step_statuses[index] = "pending"
        self._steps[index].set_status("pending")

        self._progress.set_value(0.0)

        # Start background worker thread with single_step=True
        self._worker_thread = threading.Thread(
            target=self._run_steps_worker,
            daemon=True,
            args=(index, True),  # single_step=True
        )
        self._worker_thread.start()

    def _set_step_status(self, index: int, status: str) -> None:
        """Update the status of a step in the UI.

        Args:
            index: Step index (0-based).
            status: New status string.
        """
        self._step_statuses[index] = status
        self._steps[index].set_status(status)

    def _run_all_steps(self) -> None:
        """Execute all workflow steps sequentially in a background thread."""
        if self._is_running:
            return

        self._is_running = True
        self._run_btn.configure(state="disabled", text="Running...")
        self._progress.reset()

        # Reset all step statuses
        for i in range(len(self._steps)):
            self._step_statuses[i] = "pending"
            self._steps[i].set_status("pending")

        # Start background worker thread
        self._worker_thread = threading.Thread(
            target=self._run_steps_worker,
            daemon=True,
            args=(0, False),  # single_step=False
        )
        self._worker_thread.start()

    def _run_steps_worker(self, start_index: int = 0, single_step: bool = False) -> None:
        """Worker method that runs workflow steps in the background.

        Args:
            start_index: Index of the first step to run (0-based).
            single_step: If True, only run the step at start_index.
        """
        step_funcs = [
            self._run_step_1_check_environment,
            self._run_step_2_program_flash,
            self._run_step_3_load_bootloader,
            self._run_step_4_load_main_program,
        ]
        step_timeout_keys = [
            ("check_env", 30),
            ("flash_program", 600),
            ("bitstream", 60),
            ("tftp_reboot", 120),
        ]

        # Start UART monitor if available
        self._start_uart_monitor()

        # Determine end index based on single_step flag
        end_index = start_index + 1 if single_step else len(step_funcs)
        total = end_index - start_index
        results: list[bool] = []

        for i in range(start_index, end_index):
            step_idx = i - start_index
            self._set_step_status(i, "running")

            # Step 2: expand sub-step frame and reset
            if i == 1 and hasattr(self, '_sub_step_frame'):
                self._sub_step_frame.reset()
                self._sub_step_frame.set_expanded(True)
                self._flash_phase = ""

            # Log step timeout estimate
            timeout_key, default_timeout = step_timeout_keys[i] if i < len(step_timeout_keys) else ("", 30)
            step_timeout = self._config.step_timeouts.get(timeout_key, default_timeout) if self._config else default_timeout
            self._log_message(f"  ⏱ Step {i+1} timeout: {step_timeout}s")

            self._progress.set_value(step_idx / total)
            t_step_start = time.time()

            try:
                success = step_funcs[i]()
                results.append(success)
                self._set_step_status(i, "complete" if success else "error")
                elapsed = time.time() - t_step_start
                self._log_message(f"  ⏱ Step {i+1} completed in {elapsed:.0f}s")

                # Step 2: mark sub-steps based on result
                if i == 1 and hasattr(self, '_sub_step_frame'):
                    if success:
                        self._sub_step_frame.set_phase("done")
                    else:
                        self._sub_step_frame.set_phase("error")
            except Exception as e:
                results.append(False)
                self._set_step_status(i, "error")
                self._log_message(f"  Exception in step {i+1}: {e}")

            self._progress.set_value((step_idx + 1) / total)

            # Stop on first failure when running all steps
            if not single_step and not success:
                break

            # Inter-step delay (skip after last step)
            if i < len(step_funcs) - 1:
                delay = self._config.inter_step_delay if self._config else 2
                self._log_message(f"  ⏳ Waiting {delay}s before next step...")
                time.sleep(delay)

        self._progress.set_value(1.0)
        self._is_running = False
        self._run_btn.configure(state="normal", text="▶ Run All Steps")

        # Update dependency statuses
        self._update_step_dependencies()

        # Set final status message
        if results:
            all_ok = all(results)
            any_fail = any(not r for r in results)
            if all_ok:
                self._status.set_status("Workflow complete — all steps passed", "success")
            elif any_fail:
                failed_count = results.count(False)
                self._status.set_status(
                    f"Workflow complete — {failed_count}/{len(results)} step(s) failed",
                    "warning",
                )
            else:
                self._status.set_status("Workflow complete", "info")
        else:
            self._status.set_status("Workflow complete", "info")

        # Save config after running
        self._save_config()

        # Stop UART monitor
        self._stop_uart_monitor()

    # ── UART Monitor ──────────────────────────────────────────

    def _start_uart_monitor(self) -> None:
        """Start background serial monitoring if UART is available."""
        if not self._uart_available or not self._config:
            return
        port = self._config.serial_port
        if not port:
            return

        self._uart_monitor = UartMonitor(port, self._config.serial_baudrate)
        self._uart_monitor.on_line = lambda line: self._log_message(f"  [UART] {line}")
        self._uart_monitor.on_boot_info = lambda info: (
            self._log_message(f"  [UART] Boot detected: IP={info.ip_address}, Ver={info.version}")
            if info.ip_address or info.version else None
        )
        self._uart_monitor.on_error = lambda e: self._log_message(f"  [UART] Error: {e}")
        if self._uart_monitor.start():
            self._log_message("  [UART] Serial monitor started")

    def _stop_uart_monitor(self) -> None:
        """Stop background serial monitoring."""
        if self._uart_monitor:
            self._uart_monitor.stop()
            self._uart_monitor = None

    # ── Serial ─────────────────────────────────────────────────

    def _refresh_ports(self) -> None:
        """Refresh the serial port list."""
        ports = detect_serial_ports()
        self._port_menu.configure(values=[""] + [p.device for p in ports])
        self._log_message(f"Found {len(ports)} serial port(s)")

    def _refresh_ports_initial(self) -> None:
        """Refresh the serial port list on startup (silent, no log)."""
        ports = detect_serial_ports()
        self._port_menu.configure(values=[""] + [p.device for p in ports])
        # Auto-select if only one port found and config has one
        if ports and self._config and self._config.serial_port:
            devices = [p.device for p in ports]
            if self._config.serial_port in devices:
                self._port_var.set(self._config.serial_port)

    def _on_close(self) -> None:
        """Handle window close event: save config and cleanup."""
        self._stop_uart_monitor()
        if self._config:
            self._sync_config_from_ui()  # Sync UI values first
            # Save to user config file (config.yaml)
            user_config_path = self._get_user_config_path()
            self._config._config_path = user_config_path
            try:
                self._config.save()
            except Exception:
                pass
        self.destroy()

    def _read_serial(self) -> None:
        """Read and display serial output."""
        port = self._port_var.get()
        if not port:
            self._log_message("No serial port selected")
            return

        self._log_message(f"Reading from {port}...")
        try:
            import serial

            with serial.Serial(port, self._config.serial_baudrate if self._config else 115200, timeout=5) as ser:
                ser.reset_input_buffer()
                lines = []
                while ser.in_waiting:
                    line = ser.readline().decode("utf-8", errors="replace").strip()
                    if line:
                        lines.append(line)

            if lines:
                info = parse_boot_output(lines)
                self._log_message(f"  Parsed: IP={info.ip_address}, Ver={info.version}")
                for line in lines[-10:]:
                    self._log_message(f"  > {line}")
            else:
                self._log_message("  No data received")
        except Exception as e:
            self._log_message(f"  Error: {e}")

    def _test_serial_version(self) -> None:
        """Test serial port by sending 'ver()' command and parsing response."""
        port = self._port_var.get()
        if not port:
            self._log_message("No serial port selected")
            return

        self._log_message(f"Testing version on {port}...")
        self._test_version_btn.configure(state="disabled", text="Testing...")

        # Run in background thread
        def test_version_thread():
            try:
                from serial_monitor import test_serial_version

                success, message, version = test_serial_version(
                    port,
                    self._config.serial_baudrate if self._config else 115200,
                )

                if success:
                    if version:
                        self._log_message(f"  ✓ {message}")
                        self._log_message(f"  ✓ Version detected: {version}")
                        self._status.set_status(f"Version: {version}", "success")
                    else:
                        self._log_message(f"  ✓ {message}")
                        self._status.set_status("Port responded", "info")
                else:
                    self._log_message(f"  ✗ {message}")
                    self._status.set_status(message, "error")
            except Exception as e:
                self._log_message(f"  ✗ Error: {e}")
                self._status.set_status(f"Error: {e}", "error")
            finally:
                # Re-enable button
                self.after(0, lambda: self._test_version_btn.configure(state="normal", text="Test Version"))

        threading.Thread(target=test_version_thread, daemon=True).start()

    # ── Vitis Check ────────────────────────────────────────────

    def _check_vitis(self) -> None:
        """Check Vitis/Vivado on startup."""
        if not self._config:
            return

        result = check_vitis(self._config)
        status_dict = get_tool_status_dict(result)

        if result.is_ready:
            self._vitis_status.configure(text="Vitis: Ready", text_color=SUCCESS_COLOR)
            self._log_message("Vitis/Vivado tools available")
        else:
            self._vitis_status.configure(text="Vitis: Partial", text_color=WARNING_COLOR)
            self._log_message(f"Vitis issues: {'; '.join(result.errors)}")


# ── Entry Point ────────────────────────────────────────────────

def main() -> None:
    """Launch the Zynq Flasher GUI application."""
    app = MainWindow()
    app.mainloop()


if __name__ == "__main__":
    main()