import tkinter as tk
from tkinter import ttk, messagebox
from typing import Optional


class DuplicatesDialog(tk.Toplevel):
    """Modal dialog to request duplicates search parameters.

    Returns result via the `result` attribute (dict) or None if cancelled.
    """

    def __init__(
        self, parent, initial: Optional[dict] = None, allow_edit_extensions: bool = True
    ):
        super().__init__(parent)
        self.transient(parent)
        self.grab_set()
        self.title("Duplicates search parameters")
        self.parent = parent
        self.result = None
        init = initial or {}

        # Defaults
        threshold = init.get("threshold", 5.0)
        exts = init.get("extensions")
        k = init.get("k", 25)
        window = init.get("window", 4)

        frm = ttk.Frame(self)
        frm.pack(padx=12, pady=12, fill="both", expand=True)

        # Threshold
        ttk.Label(frm, text="Max percent changed lines (dup threshold):").grid(
            row=0, column=0, sticky="w"
        )
        self.threshold_var = tk.StringVar(value=str(threshold))
        self.threshold_entry = ttk.Entry(frm, textvariable=self.threshold_var, width=12)
        self.threshold_entry.grid(row=0, column=1, sticky="w", padx=(8, 0))

        # Extensions (comma separated)
        ttk.Label(
            frm, text="Extensions to include (comma separated, e.g. .py,.c):"
        ).grid(row=1, column=0, sticky="w", pady=(8, 0))
        exts_str = ",".join(exts) if exts else ""
        self.exts_var = tk.StringVar(value=exts_str)
        self.allow_edit_extensions = bool(allow_edit_extensions)
        if self.allow_edit_extensions:
            self.exts_entry = ttk.Entry(frm, textvariable=self.exts_var, width=40)
            self.exts_entry.grid(row=1, column=1, sticky="w", padx=(8, 0), pady=(8, 0))
        else:
            # show as read-only label and hint it's provided by profile
            lbl = ttk.Label(frm, text=exts_str or "(none)")
            lbl.grid(row=1, column=1, sticky="w", padx=(8, 0), pady=(8, 0))
            hint = ttk.Label(
                frm, text="(Extensions fixed by selected profile)", foreground="#555555"
            )
            hint.grid(row=2, column=1, sticky="w", padx=(8, 0), pady=(0, 4))
            # move numeric fields down by one row
            # adjust subsequent widget grid rows below
            # We'll shift k/window placement by one
            k_row = 3
            window_row = 4

        # Fingerprint params
        if self.allow_edit_extensions:
            k_row = 2
            window_row = 3
        ttk.Label(frm, text="Fingerprint k (k-gram size):").grid(
            row=k_row, column=0, sticky="w", pady=(8, 0)
        )
        self.k_var = tk.StringVar(value=str(k))
        self.k_entry = ttk.Entry(frm, textvariable=self.k_var, width=8)
        self.k_entry.grid(row=k_row, column=1, sticky="w", padx=(8, 0), pady=(8, 0))

        ttk.Label(frm, text="Winnowing window size:").grid(
            row=window_row, column=0, sticky="w", pady=(8, 0)
        )
        self.window_var = tk.StringVar(value=str(window))
        self.window_entry = ttk.Entry(frm, textvariable=self.window_var, width=8)
        self.window_entry.grid(
            row=window_row, column=1, sticky="w", padx=(8, 0), pady=(8, 0)
        )

        # Buttons
        btn_frame = ttk.Frame(self)
        btn_frame.pack(fill="x", padx=12, pady=(0, 12))
        ok_btn = ttk.Button(btn_frame, text="✅ OK", command=self._on_ok)
        ok_btn.pack(side="right", padx=(0, 8))
        cancel_btn = ttk.Button(btn_frame, text="❌ Cancel", command=self._on_cancel)
        cancel_btn.pack(side="right")

        # make dialog centered
        self.update_idletasks()
        try:
            pw = parent.winfo_width()
            ph = parent.winfo_height()
            px = parent.winfo_rootx()
            py = parent.winfo_rooty()
            dw = self.winfo_reqwidth()
            dh = self.winfo_reqheight()
            x = px + (pw - dw) // 2
            y = py + (ph - dh) // 2
            self.geometry(f"+{x}+{y}")
        except Exception:
            pass

        self.protocol("WM_DELETE_WINDOW", self._on_cancel)
        self.threshold_entry.focus_set()

        # Legend / explanation
        expl = (
            "Legend:\n"
            "- Threshold: maximum percent of changed lines to still consider two files duplicates. Lower = stricter.\n"
            "- Extensions: file extensions to scan. If fixed by the selected profile, you cannot edit them here.\n"
            "- Fingerprint k: k-gram size used to build fingerprints (larger k = less sensitive to small changes).\n"
            "- Winnowing window: window size used by the winnowing algorithm (controls density of fingerprints)."
        )
        try:
            # place explanation under the form (non-editable label)
            expl_lbl = ttk.Label(self, text=expl, justify="left", foreground="#333333")
            expl_lbl.pack(fill="x", padx=12, pady=(0, 8))
        except Exception:
            pass

    def _on_ok(self):
        # validate threshold
        try:
            thr = float(self.threshold_var.get())
            if thr < 0 or thr > 100:
                raise ValueError()
        except Exception:
            messagebox.showwarning(
                self, "Invalid value", "Threshold must be a number between 0 and 100"
            )
            return
        # parse extensions
        exts_raw = self.exts_var.get().strip()
        exts = None
        if exts_raw:
            parts = [p.strip() for p in exts_raw.split(",") if p.strip()]
            normalized = []
            for p in parts:
                if not p.startswith("."):
                    p = "." + p
                normalized.append(p.lower())
            exts = normalized
        # k and window with safe ranges
        try:
            k = int(self.k_var.get())
            if k < 3 or k > 100:
                raise ValueError()
        except Exception:
            messagebox.showwarning(
                self, "Invalid value", "k must be an integer between 3 and 100"
            )
            return
        try:
            w = int(self.window_var.get())
            if w < 1 or w > 100:
                raise ValueError()
        except Exception:
            messagebox.showwarning(
                self, "Invalid value", "window must be an integer between 1 and 100"
            )
            return

        self.result = {
            "threshold": float(thr),
            "extensions": exts,
            "k": int(k),
            "window": int(w),
        }
        self.destroy()

    def _on_cancel(self):
        self.result = None
        self.destroy()