// The Swift Programming Language
// https://docs.swift.org/swift-book

import Foundation

public class OpenFoodFactsClient {
	let version: Int = 0
	public var prod: Bool = false
	var baseURL: URL? {
		if prod {
			return URL(
				string: "https://world.openfoodfacts.org/api/v\(version)")
		} else {
			return URL(
				string: "https://world.openfoodfacts.net/api/v\(version)")
		}
	}

	public init() {}

	public func getProductByBarcode(_ barcode: String) async throws
		-> ProductResponse
	{
		guard
			let endpoint = baseURL?.appendingPathComponent("product/\(barcode)")
		else { throw OFFError.invalidURL }
		var request = URLRequest(url: endpoint)
		request.setValue("application/json", forHTTPHeaderField: "accept")
		let (data, response) = try await URLSession.shared.data(for: request)

		guard let response = response as? HTTPURLResponse,
			response.statusCode == 200
		else {
			throw OFFError.invalidResponse
		}
		do {
			return try JSONDecoder().decode(ProductResponse.self, from: data)
		}
	}

	public struct SearchQuery {
		public let additivesTags: String?
		public let allergensTags: String?
		public let brandsTags: String?
		public let categoriesTags: String?
		public let countriesTagsEn: String?
		public let embCodesTags: String?
		public let labelsTags: String?
		public let manufacturingPlacesTags: String?
		public let nutritionGradesTags: String?
		public let originsTags: String?
		public let packagingTagsDe: String?
		public let purchasePlacesTags: String?
	}

	// public func search(_ productName: String, queryParams: SearchQuery? = nil) async throws -> SearchResponse {
	//     let qp = Mirror(reflecting: queryParams ?? {})
	//     var s: String = "?product_name=\(productName)&"
	//     for case let (label?, value) in qp.children {
	//         s += label.camelCaseToSnakeCase() + "=" + (value as! String) + "&"
	//     }
	//     guard let endpoint = baseURL?.appendingPathComponent("search\(s)") else { throw OFFError.invalidURL }
	//     var request = URLRequest(url: endpoint)
	//     request.setValue("application/json", forHTTPHeaderField: "accept")

	//     let (data, response) = try await URLSession.shared.data(for: request)
	//     guard let response = response as? HTTPURLResponse, response.statusCode == 200 else {
	//         throw OFFError.invalidResponse
	//     }
	//     do {
	//         return try JSONDecoder().decode(SearchResponse.self, from: data)
	//     }
	// }

	//https://wiki.openfoodfacts.org/API/Read/Search#Parameters
	public func search(query: PerlSearchQuery) async throws -> SearchResponse {
		let endpoint = URL(
			string:
				"https://world.openfoodfacts.org/cgi/search.pl?\(query.makeToRequest())"
		)!
		print(endpoint)
		let request = URLRequest(url: endpoint)
		// request.setValue("application/json", forHTTPHeaderField: "accept")
		let (data, response) = try await URLSession.shared.data(for: request)

		guard let response = response as? HTTPURLResponse,
			response.statusCode == 200
		else {
			throw OFFError.invalidResponse
		}
		do {
			return try JSONDecoder().decode(SearchResponse.self, from: data)
		}

	}
}

enum OFFError: Error {
	case invalidURL, invalidResponse
}