import sqlite3
import json
from pathlib import Path
from typing import Optional, Dict, List

class Database:
    """Handles all database operations"""
    
    def __init__(self, db_path: str = "data/game.db"):
        self.db_path = db_path
        Path("data").mkdir(exist_ok=True)
    
    def _get_connection(self):
        """Get database connection"""
        conn = sqlite3.connect(self.db_path)
        conn.row_factory = sqlite3.Row
        return conn
    
    def init_db(self):
        """Initialize database tables"""
        with self._get_connection() as conn:
            # Players table
            conn.execute('''
                CREATE TABLE IF NOT EXISTS players (
                    player_id TEXT PRIMARY KEY,
                    nickname TEXT UNIQUE NOT NULL,
                    money INTEGER NOT NULL,
                    population INTEGER NOT NULL,
                    color TEXT NOT NULL,
                    last_online REAL NOT NULL
                )
            ''')
            
            # Buildings table
            conn.execute('''
                CREATE TABLE IF NOT EXISTS buildings (
                    x INTEGER NOT NULL,
                    y INTEGER NOT NULL,
                    type TEXT NOT NULL,
                    owner_id TEXT NOT NULL,
                    name TEXT,
                    placed_at REAL NOT NULL,
                    PRIMARY KEY (x, y),
                    FOREIGN KEY (owner_id) REFERENCES players (player_id)
                )
            ''')
            
            conn.commit()
    
    def save_game_state(self, game_state):
        """Save complete game state to database"""
        with self._get_connection() as conn:
            # Save players using INSERT OR REPLACE to handle existing nicknames
            for player in game_state.players.values():
                conn.execute('''
                    INSERT OR REPLACE INTO players (player_id, nickname, money, population, color, last_online)
                    VALUES (?, ?, ?, ?, ?, ?)
                ''', (
                    player.player_id,
                    player.nickname,
                    player.money,
                    player.population,
                    player.color,
                    player.last_online
                ))
            
            # Save buildings
            conn.execute('DELETE FROM buildings')
            
            for building in game_state.buildings.values():
                conn.execute('''
                    INSERT INTO buildings (x, y, type, owner_id, name, placed_at)
                    VALUES (?, ?, ?, ?, ?, ?)
                ''', (
                    building.x,
                    building.y,
                    building.building_type.value,
                    building.owner_id,
                    building.name,
                    building.placed_at
                ))
            
            conn.commit()
    
    def load_game_state(self) -> dict:
        """Load complete game state from database"""
        try:
            with self._get_connection() as conn:
                # Load players
                players = []
                cursor = conn.execute('SELECT * FROM players')
                for row in cursor:
                    players.append({
                        "player_id": row["player_id"],
                        "nickname": row["nickname"],
                        "money": row["money"],
                        "population": row["population"],
                        "color": row["color"],
                        "last_online": row["last_online"]
                    })
                
                # Load buildings
                buildings = []
                cursor = conn.execute('SELECT * FROM buildings')
                for row in cursor:
                    buildings.append({
                        "x": row["x"],
                        "y": row["y"],
                        "type": row["type"],
                        "owner_id": row["owner_id"],
                        "name": row["name"],
                        "placed_at": row["placed_at"]
                    })
                
                return {
                    "players": players,
                    "buildings": buildings
                }
        except Exception as e:
            print(f"Error loading game state: {e}")
            return {"players": [], "buildings": []}