import { spawn } from "node:child_process";
import { fileURLToPath } from "node:url";
import type {
	KeePassCommand,
	KeePassEntry,
	KeePassFindQuery,
	KeePassGroup,
	KeePassOpenOptions,
	KeePassResponse,
} from "./types";

export class KeePassDatabase {
	constructor(
		private readonly path: string,
		private readonly options: KeePassOpenOptions,
		private readonly pythonPath = process.env.PYTHON_PATH ?? ".venv/bin/python3",
		private readonly bridgePath = new URL("./python/bridge.py", import.meta.url)
	) {}

	async listEntries(): Promise<KeePassEntry[]> {
		const response = await this.run<KeePassEntry[]>({ command: "list-entries" });
		return response;
	}

	async findEntries(query: KeePassFindQuery): Promise<KeePassEntry[]> {
		const response = await this.run<KeePassEntry[]>({ command: "find-entries", query });
		return response;
	}

	async listGroups(): Promise<KeePassGroup[]> {
		const response = await this.run<KeePassGroup[]>({ command: "list-groups" });
		return response;
	}

	async close(): Promise<void> {
		// No persistent process is kept alive yet.
		return;
	}

	private async run<T>(command: KeePassCommand): Promise<T> {
		const payload = JSON.stringify({
			...command,
			path: this.path,
			password: this.options.password,
			keyFile: this.options.keyFile,
		});

		const bridgeFile = fileURLToPath(this.bridgePath);
		const result = await new Promise<{ stdout: string; stderr: string; code: number }>((resolve, reject) => {
			const child = spawn(this.pythonPath, [bridgeFile], {
				stdio: ["pipe", "pipe", "pipe"],
			});

			let stdout = "";
			let stderr = "";
			let settled = false;

			try {
				child.stdin.write(payload);
				child.stdin.end();
			} catch (error) {
				reject(error);
			}

			child.stdout.on("data", (chunk) => {
				stdout += chunk.toString();
			});

			child.stderr.on("data", (chunk) => {
				stderr += chunk.toString();
			});

			child.on("error", (error) => {
				if (!settled) {
					settled = true;
					reject(error);
				}
			});

			child.on("close", (code) => {
				if (!settled) {
					settled = true;
					resolve({ stdout, stderr, code: code ?? 1 });
				}
			});
		});

		const output = result.stdout.trim();
		if (!output) {
			throw new Error(result.stderr || `Empty response from Python bridge (exit code ${result.code})`);
		}

		let parsed: KeePassResponse<T>;
		try {
			parsed = JSON.parse(output) as KeePassResponse<T>;
		} catch (error) {
			throw new Error(`Invalid JSON from Python bridge: ${error instanceof Error ? error.message : String(error)}`);
		}

		if (!parsed.ok) {
			throw new Error(parsed.error || result.stderr || `KeePass bridge error (exit code ${result.code})`);
		}

		return parsed.data;
	}
}

export function openKeePassDatabase(path: string, options: KeePassOpenOptions) {
	return new KeePassDatabase(path, options);
}