/**
 * UNIARE API 클라이언트
 */
const UaDeckApi = (() => {
    const TOKEN_KEY = 'uadeck_token';
    const USER_KEY = 'uadeck_user';

    /**
     * API 베이스 URL
     * @returns {string}
     */
    function getBaseUrl() {
        if (window.UNIARE_API_BASE) return window.UNIARE_API_BASE;
        if (window.UADECK_API_BASE) return window.UADECK_API_BASE;

        const { hostname, port, protocol } = window.location;
        const isLocal = hostname === 'localhost' || hostname === '127.0.0.1';
        // Live Server 등 정적 전용 포트 → API 컨테이너/프로세스(3000)로 직접 연결
        const proxiedWebPorts = new Set(['44082', '8080', '80', '443', '']);
        if (isLocal && port && !proxiedWebPorts.has(port)) {
            return `${protocol}//${hostname}:3000/api/v1`;
        }

        return '/api/v1';
    }

    /**
     * API 미디어 경로를 브라우저에서 로드 가능한 URL로 변환
     * (Live Server 등 API 호스트가 다른 경우 대비)
     * @param {string|null} apiPath
     * @returns {string|null}
     */
    function resolveMediaUrl(apiPath) {
        if (!apiPath) return null;
        if (apiPath.startsWith('http://') || apiPath.startsWith('https://')) return apiPath;

        const base = getBaseUrl();
        if (base.startsWith('http')) {
            const origin = base.replace(/\/api\/v1\/?$/, '');
            return `${origin}${apiPath}`;
        }
        return apiPath;
    }

    /**
     * HTTP 오류 메시지
     * @param {Response} res
     * @param {object} data
     * @returns {string}
     */
    function formatError(res, data) {
        if (res.status === 405 || res.status === 404) {
            return 'API 서버에 연결되지 않았습니다. Docker 또는 npm run api:dev 로 API를 실행하세요.';
        }
        if (res.status === 413) {
            return data.error || '업로드 크기가 제한을 초과했습니다. 고화질 옵션을 끄고 다시 시도해 주세요.';
        }
        if (res.status === 0 || res.type === 'opaque') {
            return '네트워크 오류입니다. API 서버가 실행 중인지 확인하세요.';
        }
        return data.error || `요청 실패 (${res.status})`;
    }

    /**
     * 저장된 토큰
     * @returns {string|null}
     */
    function getToken() {
        return localStorage.getItem(TOKEN_KEY);
    }

    /**
     * 캐시된 사용자
     * @returns {object|null}
     */
    function getCachedUser() {
        try {
            const raw = localStorage.getItem(USER_KEY);
            return raw ? JSON.parse(raw) : null;
        } catch {
            return null;
        }
    }

    /**
     * 인증 정보 저장
     * @param {string} token
     * @param {object} user
     */
    function saveAuth(token, user) {
        localStorage.setItem(TOKEN_KEY, token);
        localStorage.setItem(USER_KEY, JSON.stringify(user));
    }

    /**
     * 로그아웃
     */
    function logout() {
        localStorage.removeItem(TOKEN_KEY);
        localStorage.removeItem(USER_KEY);
    }

    /**
     * API 요청
     * @param {string} path
     * @param {object} [options]
     * @returns {Promise<object>}
     */
    async function request(path, options = {}) {
        const headers = { 'Content-Type': 'application/json', ...(options.headers || {}) };
        const token = getToken();
        if (token) headers.Authorization = `Bearer ${token}`;

        const res = await fetch(`${getBaseUrl()}${path}`, { ...options, headers });
        const data = await res.json().catch(() => ({}));

        if (!res.ok) {
            throw new Error(formatError(res, data));
        }
        return data;
    }

    return {
        getToken,
        getCachedUser,
        saveAuth,
        logout,
        getBaseUrl,
        resolveMediaUrl,

        /** @param {string} email @param {string} password */
        login: (email, password) =>
            request('/auth/login', { method: 'POST', body: JSON.stringify({ email, password }) }),

        /** @param {object} body */
        register: (body) =>
            request('/auth/register', { method: 'POST', body: JSON.stringify(body) }),

        getMe: () => request('/auth/me'),

        /** @param {object} body */
        updateProfile: (body) => request('/auth/me', { method: 'PUT', body: JSON.stringify(body) }),

        /** @param {string} currentPassword @param {string} newPassword */
        changePassword: (currentPassword, newPassword) =>
            request('/auth/me/password', {
                method: 'POST',
                body: JSON.stringify({ currentPassword, newPassword }),
            }),

        /** @param {string} shareCode */
        getDeck: (shareCode) => request(`/decks/${shareCode}`),

        getMyDecks: () => request('/decks'),

        /** @param {object} body */
        saveDeck: (body) => request('/decks', { method: 'POST', body: JSON.stringify(body) }),

        /** @param {string} shareCode @param {object} body */
        updateDeck: (shareCode, body) =>
            request(`/decks/${shareCode}`, { method: 'PUT', body: JSON.stringify(body) }),

        /** @param {string} shareCode */
        deleteDeck: (shareCode) => request(`/decks/${shareCode}`, { method: 'DELETE' }),

        getPresets: () => request('/decks/presets'),

        getFavorites: () => request('/decks/favorites'),

        /** @param {string[]} shareCodes */
        syncFavorites: (shareCodes) =>
            request('/decks/favorites', {
                method: 'POST',
                body: JSON.stringify({ shareCodes }),
            }),

        /** @param {string} shareCode */
        addFavorite: (shareCode) =>
            request(`/decks/favorites/${shareCode}`, { method: 'PUT' }),

        /** @param {string} shareCode */
        removeFavorite: (shareCode) =>
            request(`/decks/favorites/${shareCode}`, { method: 'DELETE' }),

        /** 관리자: 회원 목록 */
        adminGetUsers: (q = '', page = 1) =>
            request(`/admin/users?q=${encodeURIComponent(q)}&page=${page}`),

        /** @param {number} id */
        adminGetUser: (id) => request(`/admin/users/${id}`),

        /** @param {number} id @param {object} body */
        adminUpdateUser: (id, body) =>
            request(`/admin/users/${id}`, { method: 'PUT', body: JSON.stringify(body) }),

        /** @param {number} id @param {string} newPassword */
        adminResetPassword: (id, newPassword) =>
            request(`/admin/users/${id}/reset-password`, {
                method: 'POST',
                body: JSON.stringify({ newPassword }),
            }),

        adminGetDecks: () => request('/admin/decks'),

        adminGetOrphanPreviews: () => request('/admin/previews/orphans'),

        adminDeleteOrphanPreviews: () =>
            request('/admin/previews/orphans', { method: 'DELETE' }),

        /** @param {object} body */
        adminCreatePreset: (body) =>
            request('/admin/decks/preset', { method: 'POST', body: JSON.stringify(body) }),

        /** @param {string} shareCode */
        adminDeleteDeck: (shareCode) =>
            request(`/admin/decks/${shareCode}`, { method: 'DELETE' }),
    };
})();

window.UaDeckApi = UaDeckApi;