// Mock API service for development without backend
import { v4 as uuidv4 } from 'uuid';

// Mock data for knowledge bases
const mockKnowledgeBases = [
    {
        id: 'kb-001',
        name: 'Frontend Development',
        description: 'Resources and guides for frontend development including React, Vue, and Angular',
        created_at: '2023-10-15T08:30:00Z',
        updated_at: '2023-12-20T14:45:00Z',
        create_time: '2023-10-15T08:30:00Z',
        update_time: '2023-12-20T14:45:00Z',
        type: 'private',
        owner: {
            id: 'user-001',
            username: 'johndoe',
            email: 'john@example.com',
        },
        document_count: 15,
        tags: ['react', 'javascript', 'frontend'],
        permissions: {
            can_edit: true,
            can_read: true,
        },
        documents: [
            {
                id: 'doc-001',
                name: 'React Best Practices.pdf',
                description: 'A guide to React best practices and patterns',
                size: '1.2MB',
                create_time: '2023-10-20T09:15:00Z',
                update_time: '2023-10-20T09:15:00Z',
            },
            {
                id: 'doc-002',
                name: 'Vue.js Tutorial.docx',
                description: 'Step-by-step tutorial for Vue.js beginners',
                size: '850KB',
                create_time: '2023-11-05T14:30:00Z',
                update_time: '2023-11-05T14:30:00Z',
            },
            {
                id: 'doc-003',
                name: 'JavaScript ES6 Features.pdf',
                description: 'Overview of ES6 features and examples',
                size: '1.5MB',
                create_time: '2023-11-15T11:45:00Z',
                update_time: '2023-11-15T11:45:00Z',
            },
        ],
    },
    {
        id: 'kb-002',
        name: 'Backend Technologies',
        description: 'Information about backend frameworks, databases, and server configurations',
        created_at: '2023-09-05T10:15:00Z',
        updated_at: '2024-01-10T09:20:00Z',
        create_time: '2023-09-05T10:15:00Z',
        update_time: '2024-01-10T09:20:00Z',
        type: 'private',
        owner: {
            id: 'user-001',
            username: 'johndoe',
            email: 'john@example.com',
        },
        document_count: 23,
        tags: ['nodejs', 'python', 'databases'],
        permissions: {
            can_edit: true,
            can_read: true,
        },
    },
    {
        id: 'kb-003',
        name: 'DevOps Practices',
        description: 'Best practices for CI/CD, containerization, and cloud deployment',
        created_at: '2023-11-12T15:45:00Z',
        updated_at: '2024-02-05T11:30:00Z',
        create_time: '2023-11-12T15:45:00Z',
        update_time: '2024-02-05T11:30:00Z',
        type: 'public',
        owner: {
            id: 'user-002',
            username: 'janedoe',
            email: 'jane@example.com',
        },
        document_count: 18,
        tags: ['docker', 'kubernetes', 'aws'],
        permissions: {
            can_edit: false,
            can_read: true,
        },
    },
    {
        id: 'kb-004',
        name: 'Machine Learning Fundamentals',
        description: 'Introduction to machine learning concepts, algorithms, and frameworks',
        created_at: '2023-08-20T09:00:00Z',
        updated_at: '2024-01-25T16:15:00Z',
        create_time: '2023-08-20T09:00:00Z',
        update_time: '2024-01-25T16:15:00Z',
        type: 'public',
        owner: {
            id: 'user-003',
            username: 'alexsmith',
            email: 'alex@example.com',
        },
        document_count: 30,
        tags: ['ml', 'python', 'tensorflow'],
        permissions: {
            can_edit: false,
            can_read: true,
        },
    },
    {
        id: 'kb-005',
        name: 'UI/UX Design Principles',
        description: 'Guidelines for creating effective and user-friendly interfaces',
        created_at: '2023-12-01T13:20:00Z',
        updated_at: '2024-02-15T10:45:00Z',
        create_time: '2023-12-01T13:20:00Z',
        update_time: '2024-02-15T10:45:00Z',
        type: 'private',
        owner: {
            id: 'user-002',
            username: 'janedoe',
            email: 'jane@example.com',
        },
        document_count: 12,
        tags: ['design', 'ui', 'ux'],
        permissions: {
            can_edit: true,
            can_read: true,
        },
    },
    {
        id: 'kb-006',
        name: 'Mobile App Development',
        description: 'Resources for iOS, Android, and cross-platform mobile development',
        created_at: '2023-10-25T11:10:00Z',
        updated_at: '2024-01-30T14:00:00Z',
        create_time: '2023-10-25T11:10:00Z',
        update_time: '2024-01-30T14:00:00Z',
        type: 'private',
        owner: {
            id: 'user-001',
            username: 'johndoe',
            email: 'john@example.com',
        },
        document_count: 20,
        tags: ['mobile', 'react-native', 'flutter'],
        permissions: {
            can_edit: true,
            can_read: true,
        },
    },
    {
        id: 'kb-007',
        name: 'Cybersecurity Best Practices',
        description: 'Guidelines for securing applications, networks, and data',
        created_at: '2023-09-18T14:30:00Z',
        updated_at: '2024-02-10T09:15:00Z',
        create_time: '2023-09-18T14:30:00Z',
        update_time: '2024-02-10T09:15:00Z',
        type: 'private',
        owner: {
            id: 'user-004',
            username: 'sarahwilson',
            email: 'sarah@example.com',
        },
        document_count: 25,
        tags: ['security', 'encryption', 'authentication'],
        permissions: {
            can_edit: false,
            can_read: false,
        },
    },
    {
        id: 'kb-008',
        name: 'Data Science Toolkit',
        description: 'Tools and techniques for data analysis, visualization, and modeling',
        created_at: '2023-11-05T10:00:00Z',
        updated_at: '2024-01-20T15:30:00Z',
        create_time: '2023-11-05T10:00:00Z',
        update_time: '2024-01-20T15:30:00Z',
        type: 'public',
        owner: {
            id: 'user-003',
            username: 'alexsmith',
            email: 'alex@example.com',
        },
        document_count: 28,
        tags: ['data-science', 'python', 'visualization'],
        permissions: {
            can_edit: false,
            can_read: true,
        },
    },
];

// In-memory store for CRUD operations
let knowledgeBases = [...mockKnowledgeBases];

// Helper function for pagination
const paginate = (array, page_size, page) => {
    const startIndex = (page - 1) * page_size;
    const endIndex = startIndex + page_size;
    const items = array.slice(startIndex, endIndex);

    return {
        items,
        total: array.length,
        page,
        page_size,
    };
};

// Mock API functions
export const mockGet = async (url, params = {}) => {
    console.log(`[MOCK API] GET ${url}`, params);

    // Simulate network delay
    await new Promise((resolve) => setTimeout(resolve, 500));

    // Knowledge bases list with pagination
    if (url === '/knowledge-bases/') {
        const { page = 1, page_size = 10 } = params;
        return paginate(knowledgeBases, page_size, page);
    }

    // Knowledge base search
    if (url === '/knowledge-bases/search/') {
        const { keyword = '', page = 1, page_size = 10 } = params;
        const filtered = knowledgeBases.filter(
            (kb) =>
                kb.name.toLowerCase().includes(keyword.toLowerCase()) ||
                kb.description.toLowerCase().includes(keyword.toLowerCase()) ||
                kb.tags.some((tag) => tag.toLowerCase().includes(keyword.toLowerCase()))
        );
        return paginate(filtered, page_size, page);
    }

    // Knowledge base details
    if (url.match(/^\/knowledge-bases\/[^/]+\/$/)) {
        const id = url.split('/')[2];
        const knowledgeBase = knowledgeBases.find((kb) => kb.id === id);

        if (!knowledgeBase) {
            throw { response: { status: 404, data: { message: 'Knowledge base not found' } } };
        }

        return knowledgeBase;
    }

    throw { response: { status: 404, data: { message: 'Not found' } } };
};

export const mockPost = async (url, data) => {
    console.log(`[MOCK API] POST ${url}`, data);

    // Simulate network delay
    await new Promise((resolve) => setTimeout(resolve, 700));

    // Create knowledge base
    if (url === '/knowledge-bases/') {
        const newKnowledgeBase = {
            id: `kb-${uuidv4().slice(0, 8)}`,
            name: data.name,
            description: data.description || '',
            desc: data.desc || data.description || '',
            created_at: new Date().toISOString(),
            updated_at: new Date().toISOString(),
            create_time: new Date().toISOString(),
            update_time: new Date().toISOString(),
            type: data.type || 'private',
            owner: {
                id: 'user-001',
                username: 'johndoe',
                email: 'john@example.com',
            },
            document_count: 0,
            tags: data.tags || [],
            permissions: {
                can_edit: true,
                can_read: true,
            },
            documents: [],
        };

        knowledgeBases.push(newKnowledgeBase);
        return newKnowledgeBase;
    }

    throw { response: { status: 404, data: { message: 'Not found' } } };
};

export const mockPut = async (url, data) => {
    console.log(`[MOCK API] PUT ${url}`, data);

    // Simulate network delay
    await new Promise((resolve) => setTimeout(resolve, 600));

    // Update knowledge base
    if (url.match(/^\/knowledge-bases\/[^/]+\/$/)) {
        const id = url.split('/')[2];
        const index = knowledgeBases.findIndex((kb) => kb.id === id);

        if (index === -1) {
            throw { response: { status: 404, data: { message: 'Knowledge base not found' } } };
        }

        const updatedKnowledgeBase = {
            ...knowledgeBases[index],
            ...data,
            updated_at: new Date().toISOString(),
            update_time: new Date().toISOString(),
        };

        knowledgeBases[index] = updatedKnowledgeBase;
        return updatedKnowledgeBase;
    }

    throw { response: { status: 404, data: { message: 'Not found' } } };
};

export const mockDel = async (url) => {
    console.log(`[MOCK API] DELETE ${url}`);

    // Simulate network delay
    await new Promise((resolve) => setTimeout(resolve, 800));

    // Delete knowledge base
    if (url.match(/^\/knowledge-bases\/[^/]+\/$/)) {
        const id = url.split('/')[2];
        const index = knowledgeBases.findIndex((kb) => kb.id === id);

        if (index === -1) {
            throw { response: { status: 404, data: { message: 'Knowledge base not found' } } };
        }

        knowledgeBases.splice(index, 1);
        return { success: true };
    }

    throw { response: { status: 404, data: { message: 'Not found' } } };
};

// Reset mock data to initial state (useful for testing)
export const resetMockData = () => {
    knowledgeBases = [...mockKnowledgeBases];
};