/**
 * WebUI 专有 SQLite 配置存储
 *
 * 数据库文件位于扩展目录 data/webui.db，与 pi-Agent 配置完全隔离。
 */

import { existsSync, mkdirSync, readFileSync, renameSync } from "node:fs";
import { join } from "node:path";
import { DatabaseSync } from "node:sqlite";

const SCHEMA_VERSION = 1;

export interface WebuiDbInfo {
	dataDir: string;
	dbPath: string;
}

export interface WebuiAvatarSettings {
	userAvatarUrl: string;
	agentAvatarUrl: string;
}

let db: DatabaseSync | null = null;

function requireDb(): DatabaseSync {
	if (!db?.isOpen) {
		throw new Error("WebUI 数据库未初始化");
	}
	return db;
}

function getMeta(key: string): string | null {
	const row = requireDb()
		.prepare("SELECT value FROM webui_meta WHERE key = ?")
		.get(key) as { value: string } | undefined;
	return row?.value ?? null;
}

function setMeta(key: string, value: string): void {
	requireDb()
		.prepare(
			`INSERT INTO webui_meta (key, value) VALUES (?, ?)
       ON CONFLICT(key) DO UPDATE SET value = excluded.value`,
		)
		.run(key, value);
}

function migrateLegacyJsonIfNeeded(extensionDir: string): void {
	if (getMeta("legacy_json_migrated") === "1") return;

	const legacyFile = join(extensionDir, "webui-settings.json");
	if (!existsSync(legacyFile)) {
		setMeta("legacy_json_migrated", "1");
		return;
	}

	try {
		const raw = JSON.parse(readFileSync(legacyFile, "utf8")) as Partial<WebuiAvatarSettings>;
		if (typeof raw.userAvatarUrl === "string" && raw.userAvatarUrl && !getWebuiConfig("userAvatarUrl")) {
			setWebuiConfig("userAvatarUrl", raw.userAvatarUrl);
		}
		if (typeof raw.agentAvatarUrl === "string" && raw.agentAvatarUrl && !getWebuiConfig("agentAvatarUrl")) {
			setWebuiConfig("agentAvatarUrl", raw.agentAvatarUrl);
		}
		const migratedPath = `${legacyFile}.migrated`;
		if (!existsSync(migratedPath)) {
			renameSync(legacyFile, migratedPath);
		}
		console.log("[webui] 已从 webui-settings.json 迁移配置到 SQLite");
	} catch (err) {
		console.warn("[webui] 迁移 webui-settings.json 失败:", err);
	}

	setMeta("legacy_json_migrated", "1");
}

export function initWebuiDatabase(extensionDir: string): WebuiDbInfo {
	const dataDir = join(extensionDir, "data");
	const dbPath = join(dataDir, "webui.db");
	mkdirSync(dataDir, { recursive: true });

	db = new DatabaseSync(dbPath);
	db.exec("PRAGMA journal_mode = WAL;");
	db.exec("PRAGMA foreign_keys = ON;");
	db.exec(`
    CREATE TABLE IF NOT EXISTS webui_meta (
      key TEXT PRIMARY KEY NOT NULL,
      value TEXT NOT NULL
    );
    CREATE TABLE IF NOT EXISTS webui_config (
      key TEXT PRIMARY KEY NOT NULL,
      value TEXT NOT NULL,
      updated_at TEXT NOT NULL
    );
  `);

	if (!getMeta("schema_version")) {
		setMeta("schema_version", String(SCHEMA_VERSION));
	}

	migrateLegacyJsonIfNeeded(extensionDir);

	return { dataDir, dbPath };
}

export function getWebuiConfig(key: string): string | null {
	const row = requireDb()
		.prepare("SELECT value FROM webui_config WHERE key = ?")
		.get(key) as { value: string } | undefined;
	return row?.value ?? null;
}

export function setWebuiConfig(key: string, value: string): void {
	const now = new Date().toISOString();
	requireDb()
		.prepare(
			`INSERT INTO webui_config (key, value, updated_at) VALUES (?, ?, ?)
       ON CONFLICT(key) DO UPDATE SET value = excluded.value, updated_at = excluded.updated_at`,
		)
		.run(key, value, now);
}

export function setWebuiConfigMany(entries: Record<string, string>): void {
	const stmt = requireDb().prepare(
		`INSERT INTO webui_config (key, value, updated_at) VALUES (?, ?, ?)
     ON CONFLICT(key) DO UPDATE SET value = excluded.value, updated_at = excluded.updated_at`,
	);
	const now = new Date().toISOString();
	for (const [key, value] of Object.entries(entries)) {
		stmt.run(key, value, now);
	}
}

export function getAllWebuiConfig(): Record<string, string> {
	const rows = requireDb()
		.prepare("SELECT key, value FROM webui_config ORDER BY key")
		.all() as Array<{ key: string; value: string }>;
	return Object.fromEntries(rows.map((row) => [row.key, row.value]));
}

export function deleteWebuiConfig(key: string): boolean {
	const result = requireDb().prepare("DELETE FROM webui_config WHERE key = ?").run(key);
	return result.changes > 0;
}

export function readWebuiAvatarSettings(): WebuiAvatarSettings {
	return {
		userAvatarUrl: getWebuiConfig("userAvatarUrl") ?? "",
		agentAvatarUrl: getWebuiConfig("agentAvatarUrl") ?? "",
	};
}

export function writeWebuiAvatarSettings(settings: WebuiAvatarSettings): void {
	setWebuiConfigMany({
		userAvatarUrl: settings.userAvatarUrl,
		agentAvatarUrl: settings.agentAvatarUrl,
	});
}

export function closeWebuiDatabase(): void {
	if (db?.isOpen) {
		db.close();
		db = null;
	}
}

export function getWebuiDatabasePath(): string | null {
	return db?.location() ?? null;
}

const PINNED_SESSIONS_CONFIG_KEY = "pinnedSessionPaths";

export function readPinnedSessionPaths(): string[] {
	const raw = getWebuiConfig(PINNED_SESSIONS_CONFIG_KEY);
	if (!raw) return [];
	try {
		const parsed = JSON.parse(raw) as unknown;
		if (!Array.isArray(parsed)) return [];
		return parsed.filter((entry): entry is string => typeof entry === "string" && entry.trim().length > 0);
	} catch {
		return [];
	}
}

function writePinnedSessionPaths(paths: string[]): void {
	const unique: string[] = [];
	for (const path of paths) {
		if (!unique.includes(path)) unique.push(path);
	}
	setWebuiConfig(PINNED_SESSIONS_CONFIG_KEY, JSON.stringify(unique));
}

export function prunePinnedSessionPaths(validPaths: Iterable<string>): string[] {
	const valid = new Set(validPaths);
	const current = readPinnedSessionPaths();
	const pruned = current.filter((path) => valid.has(path));
	if (pruned.length !== current.length) {
		writePinnedSessionPaths(pruned);
	}
	return pruned;
}

export function pinSessionPath(path: string): string[] {
	const current = readPinnedSessionPaths();
	if (current.includes(path)) return current;
	writePinnedSessionPaths([path, ...current]);
	return readPinnedSessionPaths();
}

export function unpinSessionPath(path: string): string[] {
	const next = readPinnedSessionPaths().filter((entry) => entry !== path);
	writePinnedSessionPaths(next);
	return next;
}

export function removePinnedSessionPath(path: string): void {
	if (readPinnedSessionPaths().includes(path)) {
		unpinSessionPath(path);
	}
}

export function setSessionPinned(path: string, pinned: boolean): string[] {
	return pinned ? pinSessionPath(path) : unpinSessionPath(path);
}