"""Editor for ordered, copy-level LaTeX remarks."""
import tkinter as tk
from tkinter import messagebox, ttk

from copienator.general_remarks import remarks_for_copy, set_remarks
from .scores import score_path_for_id


class GeneralRemarksPanel(ttk.Frame):
    def __init__(self, parent, evaluation, on_change):
        super().__init__(parent)
        self.evaluation, self.on_change = evaluation, on_change
        self.busy = False
        self.valid = False
        self.remarks = []
        self.id_var = tk.StringVar()
        self.status_var = tk.StringVar()
        self.columnconfigure(1, weight=1)
        ttk.Label(self, text="Id de copie").grid(row=0, column=0, sticky="w")
        self.id_entry = ttk.Entry(self, textvariable=self.id_var)
        self.id_entry.grid(row=0, column=1, sticky="ew")
        self.listbox = tk.Listbox(self, height=4, exportselection=False)
        self.listbox.grid(row=1, column=0, columnspan=2, sticky="ew", pady=6)
        self.listbox.bind("<<ListboxSelect>>", self.select)
        self.editor = tk.Text(self, height=5, width=50, wrap="word", undo=True)
        self.editor.grid(row=2, column=0, columnspan=2, sticky="ew")
        actions = ttk.Frame(self)
        actions.grid(row=3, column=0, columnspan=2, sticky="w", pady=6)
        self.buttons = []
        for text, command in (
            ("Nouvelle", self.new), ("Enregistrer", self.save),
            ("Supprimer", self.delete), ("Monter", lambda: self.move(-1)),
            ("Descendre", lambda: self.move(1)),
        ):
            button = ttk.Button(actions, text=text, command=command)
            button.pack(side="left", padx=(0, 5))
            self.buttons.append(button)
        ttk.Label(self, text="Texte LaTeX ; chaque remarque forme un paragraphe.").grid(
            row=4, column=0, columnspan=2, sticky="w")
        ttk.Label(self, textvariable=self.status_var, wraplength=650).grid(
            row=5, column=0, columnspan=2, sticky="w", pady=6)
        self.id_var.trace_add("write", self.load)
        self.load()

    def load(self, *_):
        self.valid = False
        self.remarks = []
        try:
            path = score_path_for_id(self.evaluation, self.id_var.get())
            self.remarks = remarks_for_copy(self.evaluation, self.id_var.get())
            self.valid = True
            self.status_var.set(path.parent.name)
        except (OSError, ValueError) as exc:
            self.status_var.set(str(exc))
        self.refresh()
        self.set_busy(self.busy)

    def refresh(self, index=None):
        self.listbox.configure(state="normal")
        self.listbox.delete(0, "end")
        for i, text in enumerate(self.remarks, 1):
            self.listbox.insert("end", f"{i}. {' '.join(text.split())}")
        self.editor.configure(state="normal")
        self.editor.delete("1.0", "end")
        if index is not None:
            self.listbox.selection_set(index)
            self.listbox.see(index)
            self.editor.insert("1.0", self.remarks[index])
        self.editor.edit_reset()

    def select(self, *_):
        if self.busy:
            return
        selected = self.listbox.curselection()
        if selected:
            self.editor.delete("1.0", "end")
            self.editor.insert("1.0", self.remarks[selected[0]])
            self.editor.edit_reset()

    def new(self):
        if self.valid and not self.busy:
            self.refresh()
            self.editor.focus_set()

    def commit(self, remarks, index=None):
        try:
            previous = set_remarks(self.evaluation, self.id_var.get(), remarks)
            self.remarks = remarks
            self.refresh(index)
            if previous != remarks:
                self.on_change(self.id_var.get(), previous, remarks)
            self.status_var.set("Remarques enregistrées — lecture des annotations à revalider, « Régénérer » coché.")
        except (OSError, ValueError) as exc:
            messagebox.showerror("Remarques générales", str(exc))

    def save(self):
        if not self.valid or self.busy:
            return
        text = self.editor.get("1.0", "end-1c").strip()
        if not text:
            self.status_var.set("Saisissez une remarque ou utilisez « Supprimer ».")
            return
        remarks = self.remarks.copy()
        selected = self.listbox.curselection()
        index = selected[0] if selected else len(remarks)
        if selected:
            remarks[index] = text
        else:
            remarks.append(text)
        self.commit(remarks, index)

    def delete(self):
        selected = self.listbox.curselection()
        if self.valid and not self.busy and selected:
            remarks = self.remarks.copy()
            remarks.pop(selected[0])
            self.commit(remarks)

    def move(self, offset):
        selected = self.listbox.curselection()
        if not self.valid or self.busy or not selected:
            return
        index = selected[0]
        target = index + offset
        if 0 <= target < len(self.remarks):
            remarks = self.remarks.copy()
            remarks[index], remarks[target] = remarks[target], remarks[index]
            self.commit(remarks, target)

    def set_busy(self, busy):
        self.busy = busy
        self.id_entry.configure(state="disabled" if busy else "normal")
        state = "normal" if self.valid and not busy else "disabled"
        self.listbox.configure(state=state)
        self.editor.configure(state=state)
        for button in self.buttons:
            button.configure(state=state)