class CreditRiskAPI {
    constructor(apiToken) {
        this.apiToken = apiToken;
        this.baseURL = 'https://api.creditrisk.co.za/api';
        this.accessToken = localStorage.getItem('access_token');
        this.refreshToken = localStorage.getItem('refresh_token');
    }

    async request(endpoint, options = {}) {
        const url = `${this.baseURL}${endpoint}?api_token=${this.apiToken}`;
        
        const config = {
            headers: {
                'Content-Type': 'application/json',
                ...options.headers
            },
            ...options
        };

        if (this.accessToken && options.requiresAuth) {
            config.headers.Authorization = `Bearer ${this.accessToken}`;
        }

        try {
            let response = await fetch(url, config);
            
            // If unauthorized, try to refresh token
            if (response.status === 401 && this.refreshToken) {
                const refreshed = await this.refreshAccessToken();
                if (refreshed) {
                    config.headers.Authorization = `Bearer ${this.accessToken}`;
                    response = await fetch(url, config);
                }
            }
            
            return await response.json();
        } catch (error) {
            throw new Error(`API request failed: ${error.message}`);
        }
    }

    async login(username, password) {
        const result = await this.request('/auth', {
            method: 'POST',
            body: JSON.stringify({ username, password })
        });

        if (result.status === 'success') {
            this.accessToken = result.access_token;
            this.refreshToken = result.refresh_token;
            
            localStorage.setItem('access_token', this.accessToken);
            localStorage.setItem('refresh_token', this.refreshToken);
        }

        return result;
    }

    async refreshAccessToken() {
        try {
            const result = await this.request('/refresh', {
                method: 'POST',
                body: JSON.stringify({ refresh_token: this.refreshToken })
            });

            if (result.status === 'success') {
                this.accessToken = result.access_token;
                localStorage.setItem('access_token', this.accessToken);
                return true;
            }
        } catch (error) {
            // Refresh failed, redirect to login
            this.logout();
        }
        return false;
    }

    async logout() {
        if (this.accessToken) {
            await this.request('/logout', {
                method: 'POST',
                requiresAuth: true,
                body: JSON.stringify({ access_token: this.accessToken })
            });
        }

        this.accessToken = null;
        this.refreshToken = null;
        localStorage.removeItem('access_token');
        localStorage.removeItem('refresh_token');
    }

    async sendApplicationInvite(inviteData) {
        return await this.request('/send_application_invite', {
            method: 'POST',
            requiresAuth: true,
            body: JSON.stringify(inviteData)
        });
    }
}

// Usage
const api = new CreditRiskAPI('your-api-token-here');

// Login
api.login('user@example.com', 'password123')
    .then(result => {
        if (result.status === 'success') {
            console.log('Logged in successfully');
            
            // Send invite
            return api.sendApplicationInvite({
                email: 'customer@example.com',
                company_name: 'ABC Corp',
                contact_name: 'John Doe'
            });
        }
    })
    .then(result => {
        console.log('Invite sent:', result);
    })
    .catch(error => {
        console.error('Error:', error);
    });