import * as path from "path";
import type { PublisherConfig, PublisherState, FrontmatterMapping } from "./types";

const CONFIG_FILENAME = "sequoia.json";
const STATE_FILENAME = ".sequoia-state.json";

export async function findConfig(
	startDir: string = process.cwd(),
): Promise<string | null> {
	let currentDir = startDir;

	while (true) {
		const configPath = path.join(currentDir, CONFIG_FILENAME);
		const file = Bun.file(configPath);

		if (await file.exists()) {
			return configPath;
		}

		const parentDir = path.dirname(currentDir);
		if (parentDir === currentDir) {
			// Reached root
			return null;
		}
		currentDir = parentDir;
	}
}

export async function loadConfig(
	configPath?: string,
): Promise<PublisherConfig> {
	const resolvedPath = configPath || (await findConfig());

	if (!resolvedPath) {
		throw new Error(
			`Could not find ${CONFIG_FILENAME}. Run 'sequoia init' to create one.`,
		);
	}

	try {
		const file = Bun.file(resolvedPath);
		const content = await file.text();
		const config = JSON.parse(content) as PublisherConfig;

		// Validate required fields
		if (!config.siteUrl) throw new Error("siteUrl is required in config");
		if (!config.contentDir) throw new Error("contentDir is required in config");
		if (!config.publicationUri)
			throw new Error("publicationUri is required in config");

		return config;
	} catch (error) {
		if (error instanceof Error && error.message.includes("required")) {
			throw error;
		}
		throw new Error(`Failed to load config from ${resolvedPath}: ${error}`);
	}
}

export function generateConfigTemplate(options: {
	siteUrl: string;
	contentDir: string;
	imagesDir?: string;
	publicDir?: string;
	outputDir?: string;
	pathPrefix?: string;
	publicationUri: string;
	pdsUrl?: string;
	frontmatter?: FrontmatterMapping;
	ignore?: string[];
}): string {
	const config: Record<string, unknown> = {
		siteUrl: options.siteUrl,
		contentDir: options.contentDir,
	};

	if (options.imagesDir) {
		config.imagesDir = options.imagesDir;
	}

	if (options.publicDir && options.publicDir !== "./public") {
		config.publicDir = options.publicDir;
	}

	if (options.outputDir) {
		config.outputDir = options.outputDir;
	}

	if (options.pathPrefix && options.pathPrefix !== "/posts") {
		config.pathPrefix = options.pathPrefix;
	}

	config.publicationUri = options.publicationUri;

	if (options.pdsUrl && options.pdsUrl !== "https://bsky.social") {
		config.pdsUrl = options.pdsUrl;
	}

	if (options.frontmatter && Object.keys(options.frontmatter).length > 0) {
		config.frontmatter = options.frontmatter;
	}

	if (options.ignore && options.ignore.length > 0) {
		config.ignore = options.ignore;
	}

	return JSON.stringify(config, null, 2);
}

export async function loadState(configDir: string): Promise<PublisherState> {
	const statePath = path.join(configDir, STATE_FILENAME);
	const file = Bun.file(statePath);

	if (!(await file.exists())) {
		return { posts: {} };
	}

	try {
		const content = await file.text();
		return JSON.parse(content) as PublisherState;
	} catch {
		return { posts: {} };
	}
}

export async function saveState(
	configDir: string,
	state: PublisherState,
): Promise<void> {
	const statePath = path.join(configDir, STATE_FILENAME);
	await Bun.write(statePath, JSON.stringify(state, null, 2));
}

export function getStatePath(configDir: string): string {
	return path.join(configDir, STATE_FILENAME);
}