//
//  Copyright RevenueCat Inc. All Rights Reserved.
//
//  Licensed under the MIT License (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//      https://opensource.org/licenses/MIT
//
//  HTTPRequestPath.swift
//
//  Created by Nacho Soto on 8/8/23.

import Foundation

protocol HTTPRequestPath {

    /// The base URL for requests to this path.
    static var serverHostURL: URL { get }

    /// The fallback hosts to use when the main server is down.
    ///
    /// Not all endpoints have a fallback host, but some do.
    var fallbackHosts: [URL] { get }

    /// Whether requests to this path are authenticated.
    var authenticated: Bool { get }

    /// Whether requests to this path can be cached using `ETagManager`.
    var shouldSendEtag: Bool { get }

    /// Whether the endpoint will perform signature verification.
    var supportsSignatureVerification: Bool { get }

    /// Whether endpoint requires a nonce for signature verification.
    var needsNonceForSigning: Bool { get }

    /// The name of the endpoint.
    var name: String { get }

    /// The full relative path for this endpoint.
    var relativePath: String { get }
}

extension HTTPRequestPath {

    var fallbackHosts: [URL] {
        return []
    }

    var url: URL? { return self.url(proxyURL: nil) }

    func url(proxyURL: URL? = nil, fallbackHostIndex: Int? = nil) -> URL? {
        let baseURL: URL
        if let proxyURL {
            baseURL = proxyURL
        } else if let fallbackHostIndex {
            guard let fallbackHost = self.fallbackHosts[safe: fallbackHostIndex] else {
                return nil
            }
            baseURL = fallbackHost
        } else {
            baseURL = Self.serverHostURL
        }
        return URL(string: self.relativePath, relativeTo: baseURL)
    }
}

// MARK: - Main paths

extension HTTPRequest {

    enum Path: Hashable {

        case getCustomerInfo(appUserID: String)
        case getOfferings(appUserID: String)
        case getIntroEligibility(appUserID: String)
        case logIn
        case postAttributionData(appUserID: String)
        case postOfferForSigning
        case postReceiptData
        case postSubscriberAttributes(appUserID: String)
        case postAdServicesToken(appUserID: String)
        case health
        case appHealthReport(appUserID: String)
        case getProductEntitlementMapping
        case getCustomerCenterConfig(appUserID: String)
        case postRedeemWebPurchase

    }

    enum PaywallPath: Hashable {

        case postEvents

    }

    enum DiagnosticsPath: Hashable {

        case postDiagnostics

    }

    enum WebBillingPath: Hashable {

        case getWebProducts(appUserID: String)

    }

}

extension HTTPRequest.Path: HTTPRequestPath {

    // swiftlint:disable:next force_unwrapping
    static let serverHostURL = URL(string: "https://api.revenuecat.com")!

    var fallbackHosts: [URL] {
        switch self {
        case .getOfferings, .getProductEntitlementMapping:
            // swiftlint:disable:next force_unwrapping
            return [URL(string: "https://api-production.8-lives-cat.io")!]
        default:
            return []
        }
    }

    var authenticated: Bool {
        switch self {
        case .getCustomerInfo,
                .getOfferings,
                .getIntroEligibility,
                .logIn,
                .postAttributionData,
                .postOfferForSigning,
                .postReceiptData,
                .postSubscriberAttributes,
                .postAdServicesToken,
                .postRedeemWebPurchase,
                .getProductEntitlementMapping,
                .getCustomerCenterConfig,
                .appHealthReport:
            return true

        case .health:
            return false
        }
    }

    var shouldSendEtag: Bool {
        switch self {
        case .getCustomerInfo,
                .getOfferings,
                .getIntroEligibility,
                .logIn,
                .postAttributionData,
                .postOfferForSigning,
                .postReceiptData,
                .postSubscriberAttributes,
                .postAdServicesToken,
                .postRedeemWebPurchase,
                .getProductEntitlementMapping,
                .getCustomerCenterConfig,
                .appHealthReport:
            return true
        case .health:
            return false
        }
    }

    var supportsSignatureVerification: Bool {
        switch self {
        case .getCustomerInfo,
                .logIn,
                .postReceiptData,
                .health,
                .getOfferings,
                .getProductEntitlementMapping,
                .appHealthReport:
            return true
        case .getIntroEligibility,
                .postSubscriberAttributes,
                .postAttributionData,
                .postAdServicesToken,
                .postOfferForSigning,
                .postRedeemWebPurchase,
                .getCustomerCenterConfig:
            return false
        }
    }

    var needsNonceForSigning: Bool {
        switch self {
        case .getCustomerInfo,
                .logIn,
                .postReceiptData,
                .health:
            return true
        case .getOfferings,
                .getIntroEligibility,
                .postSubscriberAttributes,
                .postAttributionData,
                .postAdServicesToken,
                .postOfferForSigning,
                .postRedeemWebPurchase,
                .getProductEntitlementMapping,
                .getCustomerCenterConfig,
                .appHealthReport:
            return false
        }
    }

    var relativePath: String {
        return "/v1/\(self.pathComponent)"
    }

    var pathComponent: String {
        switch self {
        case let .getCustomerInfo(appUserID):
            return "subscribers/\(Self.escape(appUserID))"

        case let .getOfferings(appUserID):
            return "subscribers/\(Self.escape(appUserID))/offerings"

        case let .getIntroEligibility(appUserID):
            return "subscribers/\(Self.escape(appUserID))/intro_eligibility"

        case let .appHealthReport(appUserID):
            return "subscribers/\(Self.escape(appUserID))/health_report"

        case .logIn:
            return "subscribers/identify"

        case let .postAttributionData(appUserID):
            return "subscribers/\(Self.escape(appUserID))/attribution"

        case let .postAdServicesToken(appUserID):
            return "subscribers/\(Self.escape(appUserID))/adservices_attribution"

        case .postOfferForSigning:
            return "offers"

        case .postReceiptData:
            return "receipts"

        case let .postSubscriberAttributes(appUserID):
            return "subscribers/\(Self.escape(appUserID))/attributes"

        case .health:
            return "health"

        case .getProductEntitlementMapping:
            return "product_entitlement_mapping"

        case let .getCustomerCenterConfig(appUserID):
            return "customercenter/\(Self.escape(appUserID))"

        case .postRedeemWebPurchase:
            return "subscribers/redeem_purchase"

        }
    }

    var name: String {
        switch self {
        case .getCustomerInfo:
            return "get_customer"

        case .getOfferings:
            return "get_offerings"

        case .getIntroEligibility:
            return "get_intro_eligibility"

        case .logIn:
            return "log_in"

        case .postAttributionData:
            return "post_attribution"

        case .postAdServicesToken:
            return "post_adservices_token"

        case .postOfferForSigning:
            return "post_offer_for_signing"

        case .postReceiptData:
            return "post_receipt"

        case .postSubscriberAttributes:
            return "post_attributes"

        case .health:
            return "post_health"

        case .getProductEntitlementMapping:
            return "get_product_entitlement_mapping"

        case .getCustomerCenterConfig:
            return "customer_center"

        case .postRedeemWebPurchase:
            return "post_redeem_web_purchase"

        case .appHealthReport:
            return "get_app_health_report"

        }
    }

    private static func escape(_ appUserID: String) -> String {
        return appUserID.trimmedAndEscaped
    }
}