"""Region Selector V2 — fullscreen overlay with multi-region editing.

Features:
    - Show existing regions (numbered, with coordinates)
    - Draw new regions by click-and-drag
    - Edit existing regions: drag to move, resize handles on corners/edges
    - Number badges centered on each region
    - Coordinate labels on sides
    - ESC = cancel, Enter/double-click = confirm all, Right-click = delete hovered

Flow:
    1. Take a screenshot of the entire primary monitor (mss).
    2. Show a fullscreen, borderless, topmost tkinter window with the screenshot.
    3. Display existing regions from passed list (numbered, colored).
    4. User can draw new regions, drag-move existing, resize via handles.
    5. Return all regions as list on confirm, or None on cancel.

Runs in a separate thread to avoid tkinter ↔ Qt conflicts.
"""

from __future__ import annotations

import threading

from src.utils.logger import logger


def select_region_on_screen(
    existing_regions: list[dict] | None = None,
    auto_confirm: bool = False,
) -> list[dict] | None:
    """Open fullscreen overlay for region selection/editing.

    Args:
        existing_regions: List of dicts with {x, y, width, height} to show.
            These are editable and will be included in the return value.
        auto_confirm: If True, automatically confirm after drawing a single
            new region (no Enter/double-click needed). Used by Quick OCR.

    Returns:
        List of {x, y, width, height} dicts (all regions), or None if cancelled.
    """
    result: list[dict] | None = None
    error: Exception | None = None
    done_event = threading.Event()

    if existing_regions is None:
        existing_regions = []

    _auto_confirm = auto_confirm

    def _run_selector() -> None:
        nonlocal result, error
        try:
            import tkinter as tk
            import tkinter.font as tkfont

            import mss

            # ── Colors for up to 8 regions ──
            COLORS = [
                "#00ff88", "#ff6b6b", "#4ecdc4", "#ffe66d",
                "#a8e6cf", "#ff8a5c", "#88d8f7", "#d4a5ff",
            ]
            HANDLE_SIZE = 8

            # ── 1. Get screen dimensions ──
            with mss.mss() as sct:
                monitor = sct.monitors[1]
                scr_w, scr_h = monitor["width"], monitor["height"]

            # ── 2. Tkinter window ──
            root = tk.Tk()
            root.title("Region Selector")
            root.attributes("-fullscreen", True)
            root.attributes("-topmost", True)
            root.configure(cursor="crosshair")
            root.overrideredirect(True)
            # Semi-transparent overlay — game visible underneath
            root.attributes("-alpha", 0.35)

            canvas = tk.Canvas(root, width=scr_w, height=scr_h,
                               highlightthickness=0, cursor="crosshair",
                               bg="#0d0d1a")
            canvas.pack(fill=tk.BOTH, expand=True)

            # ── Region storage ──
            # Each region: {"x": int, "y": int, "width": int, "height": int}
            regions: list[dict] = [dict(r) for r in existing_regions]

            # Canvas item IDs for each region: {index: {rect, label, coords, handles[]}}
            region_items: dict[int, dict] = {}

            # ── State ──
            drawing = False
            draw_start_x = draw_start_y = 0
            draw_rect_id = None

            dragging_idx: int | None = None
            dragging_handle: str | None = None  # "move", "nw", "ne", "sw", "se", "n", "s", "e", "w"
            drag_offset_x = drag_offset_y = 0
            drag_orig: dict | None = None

            bold_font = tkfont.Font(family="Segoe UI", size=16, weight="bold")
            coord_font = tkfont.Font(family="Consolas", size=10)
            info_font = tkfont.Font(family="Segoe UI", size=13, weight="bold")

            # ── Instructions ──
            INSTRUCTIONS_PL = "Przeciągnij = Nowy Region  |  Przesuń Istniejący  |  Narożniki = Zmień Rozmiar  |  PPM = Usuń  |  Enter = Zatwierdź  |  ESC = Anuluj"
            INSTRUCTIONS_EN = "Drag = New Region  |  Move Existing  |  Corners = Resize  |  RMB = Delete  |  Enter = Confirm  |  ESC = Cancel"
            canvas.create_text(
                scr_w // 2, 28,
                text=INSTRUCTIONS_PL,
                fill="#ffffff", font=info_font,
            )
            canvas.create_text(
                scr_w // 2, 52,
                text=INSTRUCTIONS_EN,
                fill="#aaaaaa", font=coord_font,
            )

            # ── Draw Helpers ──

            def _color(idx: int) -> str:
                return COLORS[idx % len(COLORS)]

            def _draw_region(idx: int) -> None:
                """Draw/redraw a single region with label, coords, handles."""
                r = regions[idx]
                x, y, w, h = r["x"], r["y"], r["width"], r["height"]
                color = _color(idx)

                # Remove old items if re-drawing
                if idx in region_items:
                    for key, item_id in region_items[idx].items():
                        if key == "handles":
                            for hid in item_id:
                                canvas.delete(hid)
                        else:
                            canvas.delete(item_id)

                # Rectangle
                rect_id = canvas.create_rectangle(
                    x, y, x + w, y + h,
                    outline=color, width=2,
                )

                # Number badge in center
                cx, cy = x + w // 2, y + h // 2
                label_id = canvas.create_text(
                    cx, cy,
                    text=str(idx + 1),
                    fill=color, font=bold_font,
                )

                # Coordinate labels on sides
                coord_text = f"{x},{y}  {w}×{h}"
                coord_id = canvas.create_text(
                    x + w // 2, y - 12,
                    text=coord_text,
                    fill=color, font=coord_font,
                )

                # Resize handles (8 positions)
                handles = []
                handle_positions = {
                    "nw": (x, y),
                    "ne": (x + w, y),
                    "sw": (x, y + h),
                    "se": (x + w, y + h),
                    "n": (x + w // 2, y),
                    "s": (x + w // 2, y + h),
                    "w": (x, y + h // 2),
                    "e": (x + w, y + h // 2),
                }
                for hname, (hx, hy) in handle_positions.items():
                    hid = canvas.create_rectangle(
                        hx - HANDLE_SIZE, hy - HANDLE_SIZE,
                        hx + HANDLE_SIZE, hy + HANDLE_SIZE,
                        fill=color, outline="white", width=1,
                        tags=(f"handle_{idx}_{hname}",),
                    )
                    handles.append(hid)

                region_items[idx] = {
                    "rect": rect_id,
                    "label": label_id,
                    "coords": coord_id,
                    "handles": handles,
                }

            def _redraw_all() -> None:
                """Redraw all regions."""
                # Clear old items for removed regions
                for idx in list(region_items.keys()):
                    if idx >= len(regions):
                        for key, item_id in region_items[idx].items():
                            if key == "handles":
                                for hid in item_id:
                                    canvas.delete(hid)
                            else:
                                canvas.delete(item_id)
                        del region_items[idx]
                for i in range(len(regions)):
                    _draw_region(i)

            def _hit_test(mx: int, my: int) -> tuple[int | None, str]:
                """Find which region/handle is under mouse cursor.
                Returns (region_index, handle_name) or (None, '').
                """
                # Check handles first (higher priority)
                for idx in range(len(regions) - 1, -1, -1):
                    r = regions[idx]
                    x, y, w, h = r["x"], r["y"], r["width"], r["height"]
                    handle_positions = {
                        "nw": (x, y),
                        "ne": (x + w, y),
                        "sw": (x, y + h),
                        "se": (x + w, y + h),
                        "n": (x + w // 2, y),
                        "s": (x + w // 2, y + h),
                        "w": (x, y + h // 2),
                        "e": (x + w, y + h // 2),
                    }
                    for hname, (hx, hy) in handle_positions.items():
                        if abs(mx - hx) <= HANDLE_SIZE + 2 and abs(my - hy) <= HANDLE_SIZE + 2:
                            return idx, hname
                # Check region body (for move)
                for idx in range(len(regions) - 1, -1, -1):
                    r = regions[idx]
                    if (r["x"] <= mx <= r["x"] + r["width"] and
                            r["y"] <= my <= r["y"] + r["height"]):
                        return idx, "move"
                return None, ""

            # ── Initial draw ──
            _redraw_all()

            # ── Event Handlers ──

            def on_press(event: tk.Event) -> None:
                nonlocal drawing, draw_start_x, draw_start_y, draw_rect_id
                nonlocal dragging_idx, dragging_handle, drag_offset_x, drag_offset_y, drag_orig

                idx, handle = _hit_test(event.x, event.y)

                if idx is not None:
                    # Start dragging existing region
                    dragging_idx = idx
                    dragging_handle = handle
                    r = regions[idx]
                    drag_offset_x = event.x - r["x"]
                    drag_offset_y = event.y - r["y"]
                    drag_orig = dict(r)
                    drawing = False
                else:
                    # Start drawing new region
                    drawing = True
                    draw_start_x, draw_start_y = event.x, event.y
                    draw_rect_id = canvas.create_rectangle(
                        event.x, event.y, event.x, event.y,
                        outline="#00ffaa", width=3, dash=(8, 4),
                    )
                    dragging_idx = None

            def on_drag(event: tk.Event) -> None:
                nonlocal draw_rect_id

                if drawing and draw_rect_id is not None:
                    canvas.coords(draw_rect_id, draw_start_x, draw_start_y,
                                  event.x, event.y)
                    return

                if dragging_idx is not None and drag_orig is not None:
                    r = regions[dragging_idx]
                    ox, oy = drag_orig["x"], drag_orig["y"]
                    ow, oh = drag_orig["width"], drag_orig["height"]

                    if dragging_handle == "move":
                        r["x"] = event.x - drag_offset_x
                        r["y"] = event.y - drag_offset_y
                    elif dragging_handle == "se":
                        r["width"] = max(20, event.x - ox)
                        r["height"] = max(20, event.y - oy)
                    elif dragging_handle == "nw":
                        r["x"] = min(event.x, ox + ow - 20)
                        r["y"] = min(event.y, oy + oh - 20)
                        r["width"] = ox + ow - r["x"]
                        r["height"] = oy + oh - r["y"]
                    elif dragging_handle == "ne":
                        r["y"] = min(event.y, oy + oh - 20)
                        r["width"] = max(20, event.x - ox)
                        r["height"] = oy + oh - r["y"]
                    elif dragging_handle == "sw":
                        r["x"] = min(event.x, ox + ow - 20)
                        r["width"] = ox + ow - r["x"]
                        r["height"] = max(20, event.y - oy)
                    elif dragging_handle == "n":
                        r["y"] = min(event.y, oy + oh - 20)
                        r["height"] = oy + oh - r["y"]
                    elif dragging_handle == "s":
                        r["height"] = max(20, event.y - oy)
                    elif dragging_handle == "w":
                        r["x"] = min(event.x, ox + ow - 20)
                        r["width"] = ox + ow - r["x"]
                    elif dragging_handle == "e":
                        r["width"] = max(20, event.x - ox)

                    _draw_region(dragging_idx)

            def on_release(event: tk.Event) -> None:
                nonlocal drawing, draw_rect_id, dragging_idx, drag_orig

                if drawing and draw_rect_id is not None:
                    canvas.delete(draw_rect_id)
                    draw_rect_id = None
                    ex, ey = event.x, event.y
                    x1, y1 = min(draw_start_x, ex), min(draw_start_y, ey)
                    x2, y2 = max(draw_start_x, ex), max(draw_start_y, ey)
                    w, h = x2 - x1, y2 - y1
                    if w >= 10 and h >= 10:
                        regions.append({"x": x1, "y": y1, "width": w, "height": h})
                        _redraw_all()
                        # Auto-confirm: if exactly 1 region drawn and auto_confirm enabled
                        if _auto_confirm and len(regions) == 1:
                            root.after(120, on_confirm)
                    drawing = False

                dragging_idx = None
                drag_orig = None

            def on_right_click(event: tk.Event) -> None:
                """Right-click = delete hovered region."""
                idx, _ = _hit_test(event.x, event.y)
                if idx is not None:
                    regions.pop(idx)
                    _redraw_all()

            def on_confirm(_event: tk.Event = None) -> None:
                nonlocal result
                if regions:
                    result = regions
                else:
                    result = None
                root.destroy()

            def on_cancel(_event: tk.Event = None) -> None:
                nonlocal result
                result = None
                root.destroy()

            def on_double_click(_event: tk.Event) -> None:
                """Double-click = confirm."""
                on_confirm()

            canvas.bind("<ButtonPress-1>", on_press)
            canvas.bind("<B1-Motion>", on_drag)
            canvas.bind("<ButtonRelease-1>", on_release)
            canvas.bind("<ButtonPress-3>", on_right_click)
            canvas.bind("<Double-Button-1>", on_double_click)
            root.bind("<Return>", on_confirm)
            root.bind("<Escape>", on_cancel)

            root.mainloop()

        except Exception as exc:
            error = exc
            logger.error("Region selector error: {}", exc)
        finally:
            done_event.set()

    # Run tkinter in its own thread
    t = threading.Thread(target=_run_selector, daemon=True, name="region-selector")
    t.start()
    done_event.wait(timeout=120)

    if error:
        raise error
    return result