api-client.js

// ==========================================
// API CLIENT - SQL DATABASE COMMUNICATION
// ==========================================

const API_URL = 'http://localhost:3001/api';

class DatabaseAPI {
    // ==========================================
    // COMPLAINT OPERATIONS
    // ==========================================

    static async getAllComplaints() {
        try {
            const response = await fetch(`${API_URL}/complaints`);
            if (!response.ok) throw new Error('Failed to fetch complaints');
            const complaints = await response.json();
            console.log(`Retrieved ${complaints.length} complaints from database`);
            return complaints;
        } catch (error) {
            console.error('Error getting complaints:', error);
            return [];
        }
    }

    static async getComplaintsByStudent(studentId) {
        try {
            const response = await fetch(`${API_URL}/complaints/student/${studentId}`);
            if (!response.ok) throw new Error('Failed to fetch student complaints');
            return await response.json();
        } catch (error) {
            console.error('Error getting student complaints:', error);
            return [];
        }
    }

    static async getComplaintsByStatus(status) {
        try {
            const response = await fetch(`${API_URL}/complaints/status/${status}`);
            if (!response.ok) throw new Error('Failed to fetch complaints by status');
            return await response.json();
        } catch (error) {
            console.error('Error getting complaints by status:', error);
            return [];
        }
    }

    static async getComplaintsByCategory(category) {
        try {
            const response = await fetch(`${API_URL}/complaints/category/${category}`);
            if (!response.ok) throw new Error('Failed to fetch complaints by category');
            return await response.json();
        } catch (error) {
            console.error('Error getting complaints by category:', error);
            return [];
        }
    }

    static async getComplaintById(complaintId) {
        try {
            const response = await fetch(`${API_URL}/complaints/${complaintId}`);
            if (!response.ok) throw new Error('Failed to fetch complaint');
            return await response.json();
        } catch (error) {
            console.error('Error getting complaint by ID:', error);
            return null;
        }
    }

    static async addComplaint(complaint) {
        try {
            const response = await fetch(`${API_URL}/complaints`, {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify(complaint)
            });
            if (!response.ok) throw new Error('Failed to add complaint');
            console.log('Complaint added:', complaint.id);
            return await response.json();
        } catch (error) {
            console.error('Error adding complaint:', error);
            return null;
        }
    }

    static async updateComplaint(complaint) {
        try {
            const response = await fetch(`${API_URL}/complaints/${complaint.id}`, {
                method: 'PUT',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify(complaint)
            });
            if (!response.ok) throw new Error('Failed to update complaint');
            console.log('Complaint updated:', complaint.id);
            return await response.json();
        } catch (error) {
            console.error('Error updating complaint:', error);
            return null;
        }
    }

    static async deleteComplaint(complaintId) {
        try {
            const response = await fetch(`${API_URL}/complaints/${complaintId}`, {
                method: 'DELETE'
            });
            if (!response.ok) throw new Error('Failed to delete complaint');
            console.log('Complaint deleted:', complaintId);
            return await response.json();
        } catch (error) {
            console.error('Error deleting complaint:', error);
            return null;
        }
    }

    static async countComplaints() {
        try {
            const response = await fetch(`${API_URL}/complaints/count/total`);
            if (!response.ok) throw new Error('Failed to count complaints');
            const result = await response.json();
            return result.count || 0;
        } catch (error) {
            console.error('Error counting complaints:', error);
            return 0;
        }
    }

    // ==========================================
    // USER OPERATIONS
    // ==========================================

    static async getStudentByUsername(username) {
        try {
            const response = await fetch(`${API_URL}/users/student/${username}`);
            if (!response.ok) throw new Error('Failed to fetch student');
            return await response.json();
        } catch (error) {
            console.error('Error getting student by username:', error);
            return null;
        }
    }

    static async getAllStudents() {
        try {
            const response = await fetch(`${API_URL}/users/students/all`);
            if (!response.ok) throw new Error('Failed to fetch students');
            return await response.json();
        } catch (error) {
            console.error('Error getting all students:', error);
            return [];
        }
    }

    static async addStudent(student) {
        try {
            const response = await fetch(`${API_URL}/users/student`, {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify(student)
            });
            if (!response.ok) {
                const error = await response.json();
                throw new Error(error.error || 'Failed to add student');
            }
            console.log('Student added to database:', student.username);
            return await response.json();
        } catch (error) {
            console.error('Error adding student:', error);
            throw error;
        }
    }

    static async updateStudent(username, student) {
        try {
            const response = await fetch(`${API_URL}/users/student/${username}`, {
                method: 'PUT',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify(student)
            });
            if (!response.ok) throw new Error('Failed to update student');
            console.log('Student updated in database:', username);
            return await response.json();
        } catch (error) {
            console.error('Error updating student:', error);
            return null;
        }
    }

    static async deleteStudent(username) {
        try {
            const response = await fetch(`${API_URL}/users/student/${username}`, {
                method: 'DELETE'
            });
            if (!response.ok) throw new Error('Failed to delete student');
            console.log('Student deleted from database:', username);
            return await response.json();
        } catch (error) {
            console.error('Error deleting student:', error);
            return null;
        }
    }

    static async studentExists(username) {
        try {
            const student = await this.getStudentByUsername(username);
            return student && student.username !== undefined;
        } catch (error) {
            console.error('Error checking if student exists:', error);
            return false;
        }
    }

    // ==========================================
    // CHAT OPERATIONS
    // ==========================================

    static async addChatMessage(message) {
        try {
            const response = await fetch(`${API_URL}/chats`, {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify(message)
            });
            if (!response.ok) throw new Error('Failed to add chat message');
            console.log('✓ Chat message added to database:', message.id);
            return await response.json();
        } catch (error) {
            console.error('Error adding chat message:', error);
            throw error;
        }
    }

    static async getChatsByComplaintId(complaintId) {
        try {
            const response = await fetch(`${API_URL}/chats/complaint/${complaintId}`);
            if (!response.ok) throw new Error('Failed to fetch chat messages');
            const chats = await response.json();
            console.log(`Retrieved ${chats.length} chat messages for complaint ${complaintId}`);
            return chats;
        } catch (error) {
            console.error('Error getting chats by complaint ID:', error);
            return [];
        }
    }

    static async getAllChats() {
        try {
            const response = await fetch(`${API_URL}/chats`);
            if (!response.ok) throw new Error('Failed to fetch chats');
            return await response.json();
        } catch (error) {
            console.error('Error getting all chats:', error);
            return [];
        }
    }

    static async deleteChatsForComplaint(complaintId) {
        try {
            const response = await fetch(`${API_URL}/chats/complaint/${complaintId}`, {
                method: 'DELETE'
            });
            if (!response.ok) throw new Error('Failed to delete chats');
            console.log('Chats deleted for complaint:', complaintId);
            return await response.json();
        } catch (error) {
            console.error('Error deleting chats:', error);
            return null;
        }
    }
}

// Create global API instance
const dbAPI = DatabaseAPI;