#!/usr/bin/env python3
"""
Apply SQL migration 004 to existing database.
Migration 004: Add hostname/desktop environment/PCI/USB columns to hardware_snapshots.
Usage: python apply_migration_004.py
"""

import os
import sqlite3
from typing import Dict, List, Tuple

# Database path
DB_PATH = os.path.join(os.path.dirname(__file__), "data", "data.db")
MIGRATION_PATH = os.path.join(
    os.path.dirname(__file__), "migrations", "004_add_snapshot_details.sql"
)

COLUMNS_TO_ADD: List[Tuple[str, str]] = [
    ("hostname", "Nom d'hôte du snapshot"),
    ("desktop_environment", "Environnement de bureau détecté"),
    ("pci_devices_json", "Liste PCI en JSON"),
    ("usb_devices_json", "Liste USB en JSON"),
]


def _load_statements() -> Dict[str, str]:
    """Return ALTER TABLE statements indexed by column name."""
    with open(MIGRATION_PATH, "r", encoding="utf-8") as f:
        filtered = []
        for line in f:
            stripped = line.strip()
            if not stripped or stripped.startswith("--"):
                continue
            filtered.append(line.rstrip("\n"))

    statements: Dict[str, str] = {}
    for statement in "\n".join(filtered).split(";"):
        stmt = statement.strip()
        if not stmt:
            continue
        for column, _ in COLUMNS_TO_ADD:
            if column in stmt:
                statements[column] = stmt
                break
    return statements


def apply_migration():
    """Apply the SQL migration 004."""
    if not os.path.exists(DB_PATH):
        print(f"❌ Database not found at {DB_PATH}")
        print("   The database will be created automatically on first run.")
        return

    if not os.path.exists(MIGRATION_PATH):
        print(f"❌ Migration file not found at {MIGRATION_PATH}")
        return

    print(f"📂 Database: {DB_PATH}")
    print(f"📄 Migration: {MIGRATION_PATH}")
    print()

    conn = sqlite3.connect(DB_PATH)
    cursor = conn.cursor()

    try:
        cursor.execute("PRAGMA table_info(hardware_snapshots)")
        existing_columns = {row[1] for row in cursor.fetchall()}

        missing = [col for col, _ in COLUMNS_TO_ADD if col not in existing_columns]
        if not missing:
            print("⚠️  Migration 004 already applied (columns exist)")
            print("✅ Database is up to date")
            return

        statements = _load_statements()

        print("🔄 Applying migration 004...")
        for column, description in COLUMNS_TO_ADD:
            if column not in missing:
                print(f"⏩ Column {column} already present, skipping")
                continue
            statement = statements.get(column)
            if not statement:
                raise RuntimeError(
                    f"No SQL statement found for column '{column}' in migration file"
                )
            print(f"➕ Adding {description} ({column})...")
            cursor.execute(statement)

        conn.commit()

        print("✅ Migration 004 applied successfully!")
        print("New columns added to hardware_snapshots:")
        for column, description in COLUMNS_TO_ADD:
            if column in missing:
                print(f"  - {column}: {description}")

    except (sqlite3.Error, RuntimeError) as exc:
        print(f"❌ Error applying migration: {exc}")
        conn.rollback()
    finally:
        conn.close()


if __name__ == "__main__":
    apply_migration()