import { Platform } from 'react-native';
import type { DashboardData, OneTimeExpense, RecurringExpense, User } from '@/types';

export type LoginPayload = any;
export type RegisterPayload = any;

const BASE_URL = 'http://64.181.172.51:3333/api/v1'

let currentToken: string | null = null;

export function setApiToken(token: string | null) {
    currentToken = token;
}

async function fetcher<T>(endpoint: string, options?: RequestInit): Promise<T> {
    const url = `${BASE_URL}${endpoint}`;
    try {
        const headers: Record<string, string> = {};
        if (options?.body) {
            headers['Content-Type'] = 'application/json';
        }
        if (currentToken) {
            headers['Authorization'] = `Bearer ${currentToken}`;
        }

        const response = await fetch(url, {
            ...options,
            headers: {
                ...headers,
                ...options?.headers,
            },
        });

        if (!response.ok) {
            const errorText = await response.text();
            console.error(`API Error (${response.status}):`, errorText);
            throw new Error(`API Error: ${response.status}`);
        }

        const data = await response.json();
        return data;
    } catch (error) {
        console.error(`Fetch Error on ${endpoint}:`, error);
        throw error;
    }
}

export async function apiLogin(data: any): Promise<{ user: User; token: string }> {
    const result = await fetcher<{ data: { user: User; token: string } }>('/auth/login', {
        method: 'POST',
        body: JSON.stringify(data),
    });
    return result.data;
}

export async function apiRegister(data: any): Promise<{ user: User; token: string }> {
    const result = await fetcher<{ data: { user: User; token: string } }>('/auth/register', {
        method: 'POST',
        body: JSON.stringify(data),
    });
    return result.data;
}

export async function getDashboard(userId: number, month?: number, year?: number): Promise<DashboardData> {
    const params = new URLSearchParams();
    if (month) params.append('month', month.toString());
    if (year) params.append('year', year.toString());
    const qs = params.toString() ? `?${params.toString()}` : '';

    const result = await fetcher<{ data: DashboardData }>(`/users/${userId}/dashboard${qs}`);
    return result.data;
}

export async function updateUserSalary(
    userId: number,
    data: { gross_salary: number; net_salary_override: number | null },
): Promise<User> {
    const result = await fetcher<{ data: User }>(`/users/${userId}`, {
        method: 'PUT',
        body: JSON.stringify(data),
    });
    return result.data;
}

export async function getRecurringExpenses(userId: number): Promise<RecurringExpense[]> {
    const result = await fetcher<{ data: RecurringExpense[] }>(`/users/${userId}/recurring-expenses`);
    return result.data;
}

export async function createRecurringExpense(
    userId: number,
    data: Omit<RecurringExpense, 'id' | 'user_id' | 'created_at' | 'updated_at'>,
): Promise<RecurringExpense> {
    const result = await fetcher<{ data: RecurringExpense }>(`/users/${userId}/recurring-expenses`, {
        method: 'POST',
        body: JSON.stringify(data),
    });
    return result.data;
}

export async function toggleRecurringExpense(
    userId: number,
    expenseId: number,
): Promise<RecurringExpense> {
    const result = await fetcher<{ data: RecurringExpense }>(`/users/${userId}/recurring-expenses/${expenseId}/toggle`, {
        method: 'PATCH',
    });
    return result.data;
}

export async function updateRecurringExpense(
    userId: number,
    expenseId: number,
    data: Partial<Omit<RecurringExpense, 'id' | 'user_id' | 'created_at' | 'updated_at'>>,
): Promise<RecurringExpense> {
    const result = await fetcher<{ data: RecurringExpense }>(`/users/${userId}/recurring-expenses/${expenseId}`, {
        method: 'PUT',
        body: JSON.stringify(data),
    });
    return result.data;
}

export async function deleteRecurringExpense(userId: number, expenseId: number): Promise<void> {
    await fetcher(`/users/${userId}/recurring-expenses/${expenseId}`, {
        method: 'DELETE',
    });
}

export async function getOneTimeExpenses(userId: number, month?: number, year?: number): Promise<OneTimeExpense[]> {
    const params = new URLSearchParams();
    if (month) params.append('month', month.toString());
    if (year) params.append('year', year.toString());
    const qs = params.toString() ? `?${params.toString()}` : '';
    const result = await fetcher<{ data: OneTimeExpense[] }>(`/users/${userId}/one-time-expenses${qs}`);
    return result.data;
}

export async function createOneTimeExpense(
    userId: number,
    data: Omit<OneTimeExpense, 'id' | 'user_id' | 'created_at' | 'updated_at'>,
): Promise<OneTimeExpense> {
    const result = await fetcher<{ data: OneTimeExpense }>(`/users/${userId}/one-time-expenses`, {
        method: 'POST',
        body: JSON.stringify(data),
    });
    return result.data;
}

export async function updateOneTimeExpense(
    userId: number,
    expenseId: number,
    data: Partial<Omit<OneTimeExpense, 'id' | 'user_id' | 'created_at' | 'updated_at'>>,
): Promise<OneTimeExpense> {
    const result = await fetcher<{ data: OneTimeExpense }>(`/users/${userId}/one-time-expenses/${expenseId}`, {
        method: 'PUT',
        body: JSON.stringify(data),
    });
    return result.data;
}

export async function deleteOneTimeExpense(userId: number, expenseId: number): Promise<void> {
    await fetcher(`/users/${userId}/one-time-expenses/${expenseId}`, {
        method: 'DELETE',
    });
}