import { existsSync } from "node:fs";
import { dirname, resolve } from "node:path";
import { fileURLToPath } from "node:url";
import { type Client, createClient } from "@libsql/client";
import dotenv from "dotenv";
import { drizzle } from "drizzle-orm/libsql";
import { migrate } from "drizzle-orm/libsql/migrator";

// Load .env: try cwd first, then parent dir (for local dev running from backend/)
const envPath = process.env.DOTENV_PATH || (existsSync(".env") ? ".env" : "../.env");
dotenv.config({ path: envPath });

// Get migrations folder path (relative to this file's location)
const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);
const migrationsFolder = resolve(__dirname, "../../drizzle");

// =============================================================================
// Exported utility functions for testing
// =============================================================================

/** Split SQL string into individual statements (for backwards compatibility with tests) */
export function splitSQLStatements(sql: string): string[] {
	return sql.split(";").filter((s) => s.trim().length > 0);
}

/** Execute drizzle migrations on a database */
export async function executeMigration(
	client: Client
): Promise<{ success: boolean; executed: number; errors: string[] }> {
	const errors: string[] = [];
	const db = drizzle(client);

	try {
		await migrate(db, { migrationsFolder });

		// Count tables as a proxy for "executed" statements
		const tables = await client.execute(
			"SELECT COUNT(*) as count FROM sqlite_master WHERE type='table' AND name NOT LIKE 'sqlite_%' AND name NOT LIKE '__drizzle%'"
		);
		const executed = Number(tables.rows[0].count) || 0;

		return { success: true, executed, errors };
	} catch (err: unknown) {
		errors.push((err as Error).message);
		return { success: false, executed: 0, errors };
	}
}

/** Get a preview of statement (first N characters) */
export function getStatementPreview(stmt: string, maxLength: number = 50): string {
	const trimmed = stmt.trim();
	if (trimmed.length <= maxLength) {
		return trimmed;
	}
	return `${trimmed.substring(0, maxLength)}...`;
}

// =============================================================================
// CLI execution (only runs when called directly)
// =============================================================================

const url = "file:./data/medassist-ng.db";

async function main() {
	console.log("[DB] Starting database setup...");
	console.log("[DB] Database URL:", url);
	console.log("[DB] Migrations folder:", migrationsFolder);

	const client = createClient({ url });
	const db = drizzle(client);

	console.log("[DB] Running drizzle migrations...");
	await migrate(db, { migrationsFolder });

	console.log("[DB] Database setup complete!");
	process.exit(0);
}

// Only run main() if this file is executed directly (not imported)
const isMainModule = import.meta.url === `file://${process.argv[1]}`;
if (isMainModule) {
	main().catch((err) => {
		console.error("Migration failed:", err);
		process.exit(1);
	});
}