import z from "zod";
import { AppError, AuthenticationError, AuthorizationError, ValidationError } from "../error";

export type RequestOptions = {
	method: "GET" | "POST" | "PUT" | "DELETE";
	headers?: Record<string, string>;
	contentType?: "application/json" | "application/x-www-form-urlencoded";
	signal?: AbortSignal;
	body?: any;
	// Add more options as needed
};

export class BaseApiService {
	bearerToken: string;
	baseUrl: string;

	constructor(bearerToken: string, baseUrl: string) {
		this.bearerToken = bearerToken;
		this.baseUrl = baseUrl;
	}

	setBearerToken(bearerToken: string) {
		this.bearerToken = bearerToken;
	}

	async request<T>(
		url: string,
		body?: any,
		responseSchema?: z.ZodSchema<T>,
		options?: RequestOptions
	): Promise<T> {
		const defaultOptions: RequestOptions = {
			headers: {
				"Content-Type": "application/json",
				Authorization: `Bearer ${this.bearerToken}`,
			},
			method: "GET",
		};

		const mergedOptions: RequestOptions = {
			...defaultOptions,
			...(options ?? {}),
			headers: {
				...defaultOptions.headers,
				...(options?.headers ?? {}),
			},
		};

		let requestBody;

		// Serialize body
		if (body) {
			if (mergedOptions.headers?.["Content-Type"].toLocaleLowerCase() === "application/json") {
				requestBody = JSON.stringify(body);
			}

			if (
				mergedOptions.headers?.["Content-Type"].toLocaleLowerCase() ===
				"application/x-www-form-urlencoded"
			) {
				requestBody = new URLSearchParams(body);
			}

			mergedOptions.body = requestBody;
		}

		if (!this.baseUrl) {
			throw new AppError("Base URL is not set.");
		}

		if (!this.bearerToken) {
			throw new AuthenticationError("You are not authenticated. Please login again.");
		}

		const fullUrl = new URL(url, this.baseUrl).toString();

		const response = await fetch(fullUrl, mergedOptions);

		if (!response.ok) {
			if (response.status === 401) {
				throw new AuthenticationError("You are not authenticated. Please login again.");
			}

			if (response.status === 403) {
				throw new AuthorizationError("You don't have permission to access this resource.");
			}

			throw new AppError(`API Error: ${response.statusText}`);
		}

		let data;

		try {
			data = await response.json();
		} catch (error) {
			throw new AppError(`Failed to parse response as JSON: ${error}`);
		}

		if (!responseSchema) {
			return data;
		}

		const parsedData = responseSchema.safeParse(data);

		if (!parsedData.success) {
			throw new ValidationError(`Invalid response: ${parsedData.error.message}`);
		}

		return parsedData.data;
	}

	async get<T>(
		url: string,
		responseSchema?: z.ZodSchema<T>,
		options?: Omit<RequestOptions, "method">
	) {
		return this.request(url, undefined, responseSchema, {
			...options,
			method: "GET",
		});
	}

	async post<T>(
		url: string,
		body?: any,
		responseSchema?: z.ZodSchema<T>,
		options?: Omit<RequestOptions, "method">
	) {
		return this.request(url, body, responseSchema, {
			...options,
			method: "POST",
		});
	}

	async put<T>(
		url: string,
		body?: any,
		responseSchema?: z.ZodSchema<T>,
		options?: Omit<RequestOptions, "method">
	) {
		return this.request(url, body, responseSchema, {
			...options,
			method: "PUT",
		});
	}

	async delete<T>(
		url: string,
		body?: any,
		responseSchema?: z.ZodSchema<T>,
		options?: Omit<RequestOptions, "method">
	) {
		return this.request(url, body, responseSchema, {
			...options,
			method: "DELETE",
		});
	}
}

export const baseApiService = new BaseApiService(
	typeof window !== "undefined" ? localStorage.getItem("surfsense_bearer_token") || "" : "",
	process.env.NEXT_PUBLIC_FASTAPI_BACKEND_URL || ""
);