//
// Copyright 2026 Element Creations Ltd.
//
// SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial.
// Please see LICENSE files in the repository root for full details.
//

@testable import ElementX
import Foundation
import Synchronization
import Testing

final class HealthChatAPIServiceTests {
    private let tokenProvider = HealthChatOpenIDTokenProviderMock()
    private let service: HealthChatAPIService
    
    init() {
        MockAPIURLProtocol.reset()
        
        let configuration = URLSessionConfiguration.ephemeral
        configuration.protocolClasses = [MockAPIURLProtocol.self]
        service = HealthChatAPIService(baseURL: "https://api.test",
                                       tokenProvider: tokenProvider,
                                       urlSession: URLSession(configuration: configuration))
        
        tokenProvider.validTokenReturnValue = .success(MockAPIURLProtocol.validToken)
    }
    
    @Test
    func membersRequestsCorrectURL() async throws {
        let result = await service.members(searchQuery: nil)
        
        let response = try result.get()
        #expect(response.users.map(\.userID) == ["@alice:healthchat.ch"])
        #expect(response.isApproved)
        
        let request = try #require(MockAPIURLProtocol.lastRequest)
        #expect(request.httpMethod == "GET")
        #expect(request.url?.path() == "/api/usermatrix/users")
        #expect(request.url?.query() == nil)
        #expect(request.value(forHTTPHeaderField: "Authorization") == "Bearer \(MockAPIURLProtocol.validToken)")
    }
    
    @Test
    func membersAppendsSearchQuery() async throws {
        _ = await service.members(searchQuery: "Zürich")
        
        let url = try #require(MockAPIURLProtocol.lastRequest?.url)
        let queryItems = URLComponents(url: url, resolvingAgainstBaseURL: false)?.queryItems
        #expect(queryItems == [URLQueryItem(name: "search", value: "Zürich")])
    }
    
    @Test
    func ownProfileRequestsCorrectURL() async throws {
        let result = await service.ownProfile()
        
        let member = try result.get()
        #expect(member.userID == "@me:healthchat.ch")
        
        let request = try #require(MockAPIURLProtocol.lastRequest)
        #expect(request.httpMethod == "GET")
        #expect(request.url?.path() == "/api/usermatrix/profile")
    }
    
    @Test
    func updateOwnProfileSendsPartialJSONBody() async throws {
        var update = HealthChatProfileUpdate()
        update.businessTel = "+41 44 123 45 67"
        update.specialty = "Physiotherapie"
        
        let result = await service.updateOwnProfile(update)
        
        try result.get()
        
        let request = try #require(MockAPIURLProtocol.lastRequest)
        #expect(request.httpMethod == "PUT")
        #expect(request.url?.path() == "/api/usermatrix/profile")
        #expect(request.value(forHTTPHeaderField: "Content-Type") == "application/json")
        
        let body = try #require(MockAPIURLProtocol.lastRequestBody)
        let object = try #require(JSONSerialization.jsonObject(with: body) as? [String: Any])
        #expect(object.keys.sorted() == ["businessTel", "specialty"])
    }
    
    @Test
    func profileCompletenessRequestsCorrectURL() async throws {
        let result = await service.profileCompleteness()
        
        let completeness = try result.get()
        #expect(!completeness.isComplete)
        
        #expect(MockAPIURLProtocol.lastRequest?.url?.path() == "/api/usermatrix/profile/completeness")
    }
    
    @Test
    func inviteMemberSendsEmailAndPersonalNote() async throws {
        let result = await service.inviteMember(email: "new@example.ch", personalNote: "Bitte tritt uns bei!")
        
        try result.get()
        
        let request = try #require(MockAPIURLProtocol.lastRequest)
        #expect(request.httpMethod == "POST")
        #expect(request.url?.path() == "/api/usermatrix/invite")
        
        let body = try #require(MockAPIURLProtocol.lastRequestBody)
        let object = try #require(JSONSerialization.jsonObject(with: body) as? [String: Any])
        #expect(object["email"] as? String == "new@example.ch")
        #expect(object["personalNote"] as? String == "Bitte tritt uns bei!")
    }
    
    @Test
    func retriesOnceWithFreshTokenAfter401() async {
        let tokenRequests = Mutex(0)
        tokenProvider.validTokenClosure = {
            let count = tokenRequests.withLock { count in
                count += 1
                return count
            }
            return .success(count == 1 ? "staleToken" : MockAPIURLProtocol.validToken)
        }
        
        let result = await service.members(searchQuery: nil)
        
        #expect((try? result.get()) != nil)
        #expect(tokenProvider.invalidateTokenCallsCount == 1)
        #expect(tokenRequests.withLock { $0 } == 2)
    }
    
    @Test
    func persistent401FailsAsUnauthorized() async {
        tokenProvider.validTokenReturnValue = .success("staleToken")
        
        let result = await service.members(searchQuery: nil)
        
        #expect(result == .failure(.unauthorized))
        #expect(tokenProvider.invalidateTokenCallsCount == 1)
    }
    
    @Test
    func tokenFailurePropagatesWithoutRequest() async {
        tokenProvider.validTokenReturnValue = .failure(.tokenAcquisitionFailed)
        
        let result = await service.members(searchQuery: nil)
        
        #expect(result == .failure(.tokenAcquisitionFailed))
        #expect(MockAPIURLProtocol.lastRequest == nil)
    }
}

// MARK: - MockAPIURLProtocol

private nonisolated class MockAPIURLProtocol: URLProtocol {
    static let validToken = "freshOpenIDToken"
    
    private struct Captured {
        var request: URLRequest?
        var body: Data?
    }
    
    private static let captured: Mutex<Captured> = .init(.init())
    
    static var lastRequest: URLRequest? {
        captured.withLock { $0.request }
    }
    
    static var lastRequestBody: Data? {
        captured.withLock { $0.body }
    }
    
    static func reset() {
        captured.withLock { $0 = .init() }
    }
    
    private static let membersJSON = """
    {
        "users": [{ "userId": "@alice:healthchat.ch" }],
        "isApproved": true
    }
    """
    
    private static let profileJSON = """
    { "userId": "@me:healthchat.ch" }
    """
    
    private static let responses: [String: (Int, Data)] = [
        "/api/usermatrix/users": (200, Data(membersJSON.utf8)),
        "/api/usermatrix/profile": (200, Data(profileJSON.utf8)),
        "/api/usermatrix/profile/completeness": (200, Data(#"{ "isComplete": false, "missingFields": [], "message": "", "hasProfilePhoto": false }"#.utf8)),
        "/api/usermatrix/invite": (200, Data(#"{ "message": "ok" }"#.utf8))
    ]
    
    override func startLoading() {
        let body = Self.bodyData(of: request)
        MockAPIURLProtocol.captured.withLock {
            $0.request = request
            $0.body = body
        }
        
        guard let url = request.url else {
            client?.urlProtocol(self, didFailWithError: URLError(.badURL))
            return
        }
        
        let isAuthenticated = request.value(forHTTPHeaderField: "Authorization") == "Bearer \(MockAPIURLProtocol.validToken)"
        let (statusCode, data) = isAuthenticated ? MockAPIURLProtocol.responses[url.path()] ?? (404, Data()) : (401, Data())
        
        guard let response = HTTPURLResponse(url: url, statusCode: statusCode, httpVersion: nil, headerFields: nil) else {
            client?.urlProtocol(self, didFailWithError: URLError(.badServerResponse))
            return
        }
        
        client?.urlProtocol(self, didReceive: response, cacheStoragePolicy: .notAllowed)
        client?.urlProtocol(self, didLoad: data)
        client?.urlProtocolDidFinishLoading(self)
    }
    
    override func stopLoading() { }
    
    override class func canonicalRequest(for request: URLRequest) -> URLRequest {
        request
    }
    
    override class func canInit(with request: URLRequest) -> Bool {
        true
    }
    
    /// `URLProtocol` never sees `httpBody` for data tasks — the body only arrives as a stream.
    private static func bodyData(of request: URLRequest) -> Data? {
        if let body = request.httpBody {
            return body
        }
        guard let stream = request.httpBodyStream else {
            return nil
        }
        
        stream.open()
        defer { stream.close() }
        
        var data = Data()
        let bufferSize = 4096
        let buffer = UnsafeMutablePointer<UInt8>.allocate(capacity: bufferSize)
        defer { buffer.deallocate() }
        
        while stream.hasBytesAvailable {
            let read = stream.read(buffer, maxLength: bufferSize)
            guard read > 0 else { break }
            data.append(buffer, count: read)
        }
        return data
    }
}