import sqlite3
from tkinter import messagebox

import customtkinter as ctk

from app.database import get_connection


class BudgetsFrame(ctk.CTkFrame):
    def __init__(self, master, refresh_callback) -> None:
        super().__init__(master)
        self.refresh_callback = refresh_callback
        self.category_map: dict[str, int] = {}

        self.grid_columnconfigure(1, weight=1)
        self.grid_rowconfigure(0, weight=1)

        self._build_form()
        self._build_list()

    def _build_form(self) -> None:
        form_frame = ctk.CTkFrame(self, corner_radius=18)
        form_frame.grid(row=0, column=0, sticky="ns", padx=(8, 12), pady=8)

        title = ctk.CTkLabel(
            form_frame,
            text="Бюджеты и лимиты",
            font=ctk.CTkFont(size=26, weight="bold"),
        )
        title.pack(anchor="w", padx=18, pady=(18, 6))

        subtitle = ctk.CTkLabel(
            form_frame,
            text="Ограничения по категориям на месяц.",
            text_color="gray75",
        )
        subtitle.pack(anchor="w", padx=18, pady=(0, 18))

        self.category_menu = ctk.CTkOptionMenu(
            form_frame,
            width=300,
            values=["Нет категорий"],
        )
        self.category_menu.pack(padx=18, pady=8)

        self.limit_entry = ctk.CTkEntry(
            form_frame,
            width=300,
            placeholder_text="Лимит",
        )
        self.limit_entry.pack(padx=18, pady=8)

        add_button = ctk.CTkButton(
            form_frame,
            text="Добавить лимит",
            width=300,
            height=42,
            command=self.add_budget,
        )
        add_button.pack(padx=18, pady=(12, 18))

    def _build_list(self) -> None:
        self.list_frame = ctk.CTkScrollableFrame(
            self,
            label_text="Лимиты по категориям",
        )
        self.list_frame.grid(row=0, column=1, sticky="nsew", padx=(0, 8), pady=8)

    def _load_categories(self) -> None:
        with get_connection() as connection:
            rows = connection.execute(
                """
                SELECT id, name
                FROM categories
                WHERE category_type = 'Расход'
                ORDER BY name
                """
            ).fetchall()

        if not rows:
            self.category_map = {}
            self.category_menu.configure(values=["Нет категорий"])
            self.category_menu.set("Нет категорий")
            return

        values = []
        self.category_map = {}

        for row in rows:
            label = f"{row['name']} (ID {row['id']})"
            values.append(label)
            self.category_map[label] = row["id"]

        self.category_menu.configure(values=values)
        self.category_menu.set(values[0])

    def add_budget(self) -> None:
        category_label = self.category_menu.get()
        limit_text = self.limit_entry.get().strip().replace(",", ".")

        if category_label not in self.category_map or not limit_text:
            messagebox.showerror("Ошибка", "Выберите категорию и введите лимит.")
            return

        try:
            limit_amount = float(limit_text)
        except ValueError:
            messagebox.showerror("Ошибка", "Лимит должен быть числом.")
            return

        if limit_amount <= 0:
            messagebox.showerror("Ошибка", "Лимит должен быть больше нуля.")
            return

        category_id = self.category_map[category_label]

        try:
            with get_connection() as connection:
                connection.execute(
                    """
                    INSERT INTO budgets (category_id, limit_amount)
                    VALUES (?, ?)
                    """,
                    (category_id, limit_amount),
                )
                connection.commit()
        except sqlite3.IntegrityError:
            messagebox.showerror(
                "Ошибка",
                "Для этой категории лимит уже создан.",
            )
            return

        self.limit_entry.delete(0, "end")
        self.refresh_callback()

    def delete_budget(self, budget_id: int) -> None:
        with get_connection() as connection:
            connection.execute(
                "DELETE FROM budgets WHERE id = ?",
                (budget_id,),
            )
            connection.commit()

        self.refresh_callback()

    def refresh_data(self) -> None:
        self._load_categories()

        for widget in self.list_frame.winfo_children():
            widget.destroy()

        with get_connection() as connection:
            rows = connection.execute(
                """
                SELECT b.id,
                       b.limit_amount,
                       c.name AS category_name,
                       COALESCE(
                           SUM(
                               CASE
                                   WHEN strftime('%Y-%m', t.created_at) = strftime('%Y-%m', 'now')
                                   THEN t.amount
                                   ELSE 0
                               END
                           ),
                           0
                       ) AS spent
                FROM budgets AS b
                JOIN categories AS c ON c.id = b.category_id
                LEFT JOIN transactions AS t
                    ON t.category_id = b.category_id
                   AND t.transaction_type = 'Расход'
                GROUP BY b.id, b.limit_amount, c.name
                ORDER BY c.name
                """
            ).fetchall()

        if not rows:
            empty_label = ctk.CTkLabel(
                self.list_frame,
                text="Лимитов пока нет.",
                text_color="gray70",
            )
            empty_label.pack(anchor="w", padx=10, pady=10)
            return

        for row in rows:
            card = ctk.CTkFrame(self.list_frame, corner_radius=16)
            card.pack(fill="x", padx=6, pady=6)

            title = ctk.CTkLabel(
                card,
                text=row["category_name"],
                font=ctk.CTkFont(size=18, weight="bold"),
            )
            title.grid(row=0, column=0, sticky="w", padx=16, pady=(12, 4))

            delete_button = ctk.CTkButton(
                card,
                text="Удалить",
                width=90,
                fg_color="#b33939",
                hover_color="#932f2f",
                command=lambda budget_id=row["id"]: self.delete_budget(budget_id),
            )
            delete_button.grid(row=0, column=1, sticky="e", padx=16, pady=(12, 4))

            percent = 0 if row["limit_amount"] == 0 else row["spent"] / row["limit_amount"]
            percent = max(0, percent)

            info = ctk.CTkLabel(
                card,
                text=(
                    f"Потрачено: {row['spent']:,.2f} ₽ "
                    f"из {row['limit_amount']:,.2f} ₽"
                ).replace(",", " "),
                text_color="gray75",
            )
            info.grid(row=1, column=0, columnspan=2, sticky="w", padx=16, pady=(0, 10))

            progress = ctk.CTkProgressBar(card, width=360)
            progress.grid(row=2, column=0, columnspan=2, sticky="w", padx=16, pady=(0, 8))
            progress.set(min(percent, 1))

            status_text = (
                "Лимит превышен"
                if percent > 1
                else f"Использовано: {percent * 100:.0f}%"
            )

            status = ctk.CTkLabel(
                card,
                text=status_text,
                text_color="gray75",
            )
            status.grid(row=3, column=0, columnspan=2, sticky="w", padx=16, pady=(0, 14))