"""
Kombinovaný viewer: náhled originálu + náhled duplicit + listbox duplicit.
Nahrazuje preview_viewer.py pro hlavní dokument.

Spouští se jako subprocess z extract_patient_info_novy_test.py.
Argumenty: duplicity_viewer.py <json_soubor> [--write-geometry=<cesta>]

JSON vstup: {
    "original":  "cesta/k/originalu.pdf",   # povinné
    "duplicity": ["cesta1.pdf", ...],        # volitelné, může být prázdné
    "labels":    ["název1.pdf", ...]         # zobrazované názvy v listboxu
}

Výstup geometrie (spodní hrana) do --write-geometry souboru pro rename_dialog.
"""
import json
import sys
from pathlib import Path
import tkinter as tk

if sys.platform == "win32":
    try:
        from ctypes import windll
        windll.shcore.SetProcessDpiAwareness(1)
    except Exception:
        pass
    import io
    sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding="utf-8", errors="replace")
    sys.stderr = io.TextIOWrapper(sys.stderr.buffer, encoding="utf-8", errors="replace")


def _open_doc(path_str: str):
    """Otevře PDF nebo obrázek, vrátí (fitz.Document nebo None, PIL.Image nebo None)."""
    import fitz
    from PIL import Image
    p = Path(path_str)
    if not p.exists():
        return None, None
    suffix = p.suffix.lower()
    if suffix in (".jpg", ".jpeg", ".png"):
        return None, Image.open(p)
    return fitz.open(str(p)), None


def _render_page(doc, pil_img, page_n: int, max_w: int, max_h: int):
    """Vykreslí stránku, vrátí PIL.Image."""
    import fitz
    from PIL import Image
    if doc is not None:
        page = doc[page_n]
        zoom = min(max_w / page.rect.width, max_h / page.rect.height)
        pix = page.get_pixmap(matrix=fitz.Matrix(zoom, zoom))
        return Image.frombytes("RGB", (pix.width, pix.height), pix.samples)
    elif pil_img is not None:
        img = pil_img.copy()
        img.thumbnail((max_w, max_h))
        return img
    return None


class PdfPane:
    """Jeden panel s náhledem PDF + navigací stránek."""

    def __init__(self, parent, max_w: int, max_h: int, bg: str = "#222"):
        self.max_w = max_w
        self.max_h = max_h
        self.doc = None
        self.pil_img = None
        self.page_n = 0
        self.page_count = 1
        self.photo_ref = None

        self.frame = tk.Frame(parent, bg=bg, width=max_w)
        self.frame.pack_propagate(False)

        self.lbl_title = tk.Label(self.frame, text="", bg=bg, fg="#aaa",
                                  font=("Segoe UI", 9), wraplength=max_w - 10)
        self.lbl_title.pack(pady=(4, 2))

        self.lbl_img = tk.Label(self.frame, bg=bg)
        self.lbl_img.pack(fill="both", expand=True)

        frame_nav = tk.Frame(self.frame, bg=bg)
        frame_nav.pack(pady=4)

        self.lbl_page = tk.Label(frame_nav, text="", bg=bg, fg="#ccc",
                                 font=("Segoe UI", 9))
        self.lbl_page.pack(side="left", padx=6)

        self.btn_prev = tk.Button(frame_nav, text="◄", bg="#444", fg="#fff",
                                  relief="flat", padx=6,
                                  command=self._prev)
        self.btn_prev.pack(side="left", padx=2)

        self.btn_next = tk.Button(frame_nav, text="►", bg="#444", fg="#fff",
                                  relief="flat", padx=6,
                                  command=self._next)
        self.btn_next.pack(side="left", padx=2)

    def load(self, path_str: str, title: str = ""):
        from PIL import ImageTk
        if self.doc:
            try:
                self.doc.close()
            except Exception:
                pass
        self.doc, self.pil_img = _open_doc(path_str)
        self.page_count = len(self.doc) if self.doc else 1
        self.lbl_title.config(text=title or Path(path_str).name, fg="#ddd")
        self._show(0)

    def clear(self, msg: str = ""):
        if self.doc:
            try:
                self.doc.close()
            except Exception:
                pass
        self.doc = None
        self.pil_img = None
        self.lbl_img.config(image="")
        self.lbl_title.config(text=msg, fg="#666")
        self.lbl_page.config(text="")
        self.btn_prev.config(state="disabled")
        self.btn_next.config(state="disabled")
        self.photo_ref = None

    def _show(self, n: int):
        from PIL import ImageTk
        self.page_n = n
        img = _render_page(self.doc, self.pil_img, n, self.max_w - 10, self.max_h - 60)
        if img:
            self.photo_ref = ImageTk.PhotoImage(img)
            self.lbl_img.config(image=self.photo_ref)
        self.lbl_page.config(text=f"{n + 1} / {self.page_count}" if self.page_count > 1 else "")
        self.btn_prev.config(state="normal" if n > 0 else "disabled")
        self.btn_next.config(state="normal" if n < self.page_count - 1 else "disabled")

    def _prev(self):
        if self.page_n > 0:
            self._show(self.page_n - 1)

    def _next(self):
        if self.page_n < self.page_count - 1:
            self._show(self.page_n + 1)

    def close(self):
        if self.doc:
            try:
                self.doc.close()
            except Exception:
                pass


def main():
    if len(sys.argv) < 2:
        sys.exit(1)

    data = json.loads(Path(sys.argv[1]).read_text(encoding="utf-8"))
    original_path = data.get("original") or ""
    duplicity_paths = data.get("duplicity") or []
    labels = data.get("labels") or [Path(p).name for p in duplicity_paths]

    write_geom = None
    for arg in sys.argv:
        if arg.startswith("--write-geometry="):
            write_geom = Path(arg.split("=", 1)[1])

    try:
        from PIL import Image, ImageTk
        import fitz
    except ImportError as e:
        print(f"[duplicity_viewer] Chybí knihovna: {e}", file=sys.stderr)
        sys.exit(2)

    # ── Layout z JSON ─────────────────────────────────────────────────────────
    sys.path.insert(0, str(Path(__file__).parent))
    try:
        from window_layout import get_layout
        layout = get_layout()
        lw = layout.get("duplicity_viewer") or {}
    except Exception:
        lw = {}

    WIN_X = lw.get("x", 0)
    WIN_Y = lw.get("y", 0)
    WIN_W = lw.get("w", 2200)
    WIN_H = lw.get("h", 1080)

    LISTBOX_W = 380
    PANE_W = (WIN_W - LISTBOX_W - 20) // 2
    PANE_H = WIN_H - 40

    # ── Okno ──────────────────────────────────────────────────────────────────
    root = tk.Tk()
    root.tk.call("encoding", "system", "utf-8")
    root.title("Náhled dokumentů")
    root.configure(bg="#1a1a1a")
    root.geometry(f"{WIN_W}x{WIN_H}+{WIN_X}+{WIN_Y}")

    # ── Tři sloupce ───────────────────────────────────────────────────────────
    # Vlevo: originál
    pane_orig = PdfPane(root, max_w=PANE_W, max_h=PANE_H, bg="#1e1e2e")
    pane_orig.frame.pack(side="left", fill="both", expand=False, padx=(6, 3), pady=6)

    # Uprostřed: duplicita
    pane_dup = PdfPane(root, max_w=PANE_W, max_h=PANE_H, bg="#2e1e1e")
    pane_dup.frame.pack(side="left", fill="both", expand=False, padx=(3, 3), pady=6)

    # Vpravo: listbox
    frame_right = tk.Frame(root, bg="#1a1a1a", width=LISTBOX_W)
    frame_right.pack(side="left", fill="y", padx=(3, 6), pady=6)
    frame_right.pack_propagate(False)

    tk.Label(frame_right, text="Existující dokumenty:", anchor="w",
             bg="#1a1a1a", fg="#cc4444", font=("Segoe UI", 9, "bold")).pack(
        fill="x", padx=4, pady=(8, 2))

    sb = tk.Scrollbar(frame_right, orient="vertical")
    lb = tk.Listbox(
        frame_right,
        yscrollcommand=sb.set,
        font=("Segoe UI", 8),
        selectmode="single",
        activestyle="dotbox",
        bg="#2a1a1a",
        fg="#ddd",
        selectbackground="#cc4444",
        selectforeground="#fff",
        cursor="hand2",
    )
    sb.config(command=lb.yview)
    sb.pack(side="right", fill="y")
    lb.pack(side="left", fill="both", expand=True, padx=(4, 0))

    if not duplicity_paths:
        lb.insert(tk.END, "(žádné duplicity)")
        lb.config(state="disabled")
    else:
        for label in labels:
            lb.insert(tk.END, Path(label).name if Path(label).exists() else label)

    # ── Načti originál ────────────────────────────────────────────────────────
    if original_path and Path(original_path).exists():
        pane_orig.load(original_path, title=Path(original_path).name)
    else:
        pane_orig.clear(msg="(originál nedostupný)")

    pane_dup.clear(msg="← vyberte duplicitu vlevo" if duplicity_paths else "(žádné duplicity)")

    # ── Výběr duplicity ───────────────────────────────────────────────────────
    def on_select(event):
        sel = lb.curselection()
        if not sel:
            return
        idx = sel[0]
        p = duplicity_paths[idx]
        pane_dup.load(p, title=labels[idx] if idx < len(labels) else Path(p).name)

    lb.bind("<<ListboxSelect>>", on_select)

    # Automaticky vyber první duplicitu
    if duplicity_paths:
        lb.selection_set(0)
        lb.event_generate("<<ListboxSelect>>")

    # ── Zavření ───────────────────────────────────────────────────────────────
    def on_close():
        pane_orig.close()
        pane_dup.close()
        root.destroy()

    root.protocol("WM_DELETE_WINDOW", on_close)

    # ── Geometrie pro rename_dialog ───────────────────────────────────────────
    root.update_idletasks()
    if write_geom:
        _y = root.winfo_y()
        _h = root.winfo_height()
        write_geom.write_text(
            json.dumps({"x": WIN_X, "y": _y, "w": WIN_W, "h": _h}),
            encoding="utf-8"
        )

    root.lift()
    root.attributes("-topmost", True)
    root.after(1500, lambda: root.attributes("-topmost", False))
    root.mainloop()


if __name__ == "__main__":
    main()