/**
 * API 통신 유틸리티
 */
class API {
    constructor() {
        this.baseURL = 'http://localhost:24102/api';
        this.token = localStorage.getItem('access_token');
    }

    // 토큰 설정
    setToken(token) {
        this.token = token;
        if (token) {
            localStorage.setItem('access_token', token);
        } else {
            localStorage.removeItem('access_token');
        }
    }

    // 기본 요청 헤더
    getHeaders() {
        const headers = {
            'Content-Type': 'application/json',
        };
        
        if (this.token) {
            headers['Authorization'] = `Bearer ${this.token}`;
        }
        
        return headers;
    }

    // GET 요청
    async get(endpoint, params = {}) {
        const url = new URL(`${this.baseURL}${endpoint}`, window.location.origin);
        Object.keys(params).forEach(key => {
            if (params[key] !== null && params[key] !== undefined) {
                url.searchParams.append(key, params[key]);
            }
        });

        const response = await fetch(url, {
            method: 'GET',
            headers: this.getHeaders(),
        });

        return this.handleResponse(response);
    }

    // POST 요청
    async post(endpoint, data = {}) {
        const response = await fetch(`${this.baseURL}${endpoint}`, {
            method: 'POST',
            headers: this.getHeaders(),
            body: JSON.stringify(data),
        });

        return this.handleResponse(response);
    }

    // PUT 요청
    async put(endpoint, data = {}) {
        const response = await fetch(`${this.baseURL}${endpoint}`, {
            method: 'PUT',
            headers: this.getHeaders(),
            body: JSON.stringify(data),
        });

        return this.handleResponse(response);
    }

    // DELETE 요청
    async delete(endpoint) {
        const response = await fetch(`${this.baseURL}${endpoint}`, {
            method: 'DELETE',
            headers: this.getHeaders(),
        });

        return this.handleResponse(response);
    }

    // 파일 업로드
    async uploadFile(endpoint, formData) {
        const headers = {};
        if (this.token) {
            headers['Authorization'] = `Bearer ${this.token}`;
        }

        const response = await fetch(`${this.baseURL}${endpoint}`, {
            method: 'POST',
            headers: headers,
            body: formData,
        });

        return this.handleResponse(response);
    }

    // 응답 처리
    async handleResponse(response) {
        if (response.status === 401) {
            // 토큰 만료 또는 인증 실패
            this.setToken(null);
            window.location.reload();
            throw new Error('인증이 필요합니다');
        }

        if (!response.ok) {
            const errorData = await response.json().catch(() => ({}));
            throw new Error(errorData.detail || `HTTP ${response.status}`);
        }

        const contentType = response.headers.get('content-type');
        if (contentType && contentType.includes('application/json')) {
            return await response.json();
        }

        return await response.text();
    }

    // 인증 관련 API
    async login(email, password) {
        return await this.post('/auth/login', { email, password });
    }

    async logout() {
        try {
            await this.post('/auth/logout');
        } finally {
            this.setToken(null);
        }
    }

    async getCurrentUser() {
        return await this.get('/auth/me');
    }

    async refreshToken(refreshToken) {
        return await this.post('/auth/refresh', { refresh_token: refreshToken });
    }

    // 문서 관련 API
    async getDocuments(params = {}) {
        return await this.get('/documents/', params);
    }

    async getDocument(documentId) {
        return await this.get(`/documents/${documentId}`);
    }

    async uploadDocument(formData) {
        return await this.uploadFile('/documents/', formData);
    }

    async deleteDocument(documentId) {
        return await this.delete(`/documents/${documentId}`);
    }

    async getTags() {
        return await this.get('/documents/tags/');
    }

    async createTag(tagData) {
        return await this.post('/documents/tags/', tagData);
    }

    // 하이라이트 관련 API
    async createHighlight(highlightData) {
        return await this.post('/highlights/', highlightData);
    }

    async getDocumentHighlights(documentId) {
        return await this.get(`/highlights/document/${documentId}`);
    }

    async updateHighlight(highlightId, data) {
        return await this.put(`/highlights/${highlightId}`, data);
    }

    async deleteHighlight(highlightId) {
        return await this.delete(`/highlights/${highlightId}`);
    }

    // 메모 관련 API
    async createNote(noteData) {
        return await this.post('/notes/', noteData);
    }

    async getNotes(params = {}) {
        return await this.get('/notes/', params);
    }

    async getDocumentNotes(documentId) {
        return await this.get(`/notes/document/${documentId}`);
    }

    async updateNote(noteId, data) {
        return await this.put(`/notes/${noteId}`, data);
    }

    async deleteNote(noteId) {
        return await this.delete(`/notes/${noteId}`);
    }

    async getPopularNoteTags() {
        return await this.get('/notes/tags/popular');
    }

    // 책갈피 관련 API
    async createBookmark(bookmarkData) {
        return await this.post('/bookmarks/', bookmarkData);
    }

    async getBookmarks(params = {}) {
        return await this.get('/bookmarks/', params);
    }

    async getDocumentBookmarks(documentId) {
        return await this.get(`/bookmarks/document/${documentId}`);
    }

    async updateBookmark(bookmarkId, data) {
        return await this.put(`/bookmarks/${bookmarkId}`, data);
    }

    async deleteBookmark(bookmarkId) {
        return await this.delete(`/bookmarks/${bookmarkId}`);
    }

    // 검색 관련 API
    async search(params = {}) {
        return await this.get('/search/', params);
    }

    async getSearchSuggestions(query) {
        return await this.get('/search/suggestions', { q: query });
    }

    // 사용자 관리 API
    async getUsers() {
        return await this.get('/users/');
    }

    async createUser(userData) {
        return await this.post('/auth/create-user', userData);
    }

    async updateUser(userId, userData) {
        return await this.put(`/users/${userId}`, userData);
    }

    async deleteUser(userId) {
        return await this.delete(`/users/${userId}`);
    }

    async updateProfile(profileData) {
        return await this.put('/users/profile', profileData);
    }

    async changePassword(passwordData) {
        return await this.put('/auth/change-password', passwordData);
    }
}

// 전역 API 인스턴스
window.api = new API();