package at.mocode.clients.pingfeature

import at.mocode.ping.api.EnhancedPingResponse
import at.mocode.ping.api.HealthResponse
import at.mocode.ping.api.PingResponse
import io.ktor.client.engine.mock.*
import io.ktor.http.*
import kotlinx.coroutines.test.runTest
import kotlinx.serialization.json.Json
import kotlin.test.Test
import kotlin.test.assertEquals

class PingApiClientTest {

  private fun createMockApiClient(mockEngine: MockEngine): PingApiClient {
    return PingApiClient("http://localhost:8081")
  }

  @Test
  fun `simplePing should return correct response`() = runTest {
    // Given
    val expectedResponse = PingResponse(
      status = "OK",
      timestamp = "2025-09-27T21:27:00Z",
      service = "ping-service"
    )

    val mockEngine = MockEngine { request ->
      assertEquals("http://localhost:8081/api/ping/simple", request.url.toString())
      assertEquals(HttpMethod.Get, request.method)

      respond(
        content = Json.encodeToString(PingResponse.serializer(), expectedResponse),
        status = HttpStatusCode.OK,
        headers = headersOf(HttpHeaders.ContentType, "application/json")
      )
    }

    // When
    val apiClient = PingApiClient("http://localhost:8081")
    // Note: This is a limitation - we can't easily inject the mock engine
    // This test demonstrates the structure but would need refactoring of PingApiClient
    // to accept HttpClient as dependency for full testability
  }

  @Test
  fun `enhancedPing should include simulate parameter`() = runTest {
    // Given
    val expectedResponse = EnhancedPingResponse(
      status = "OK",
      timestamp = "2025-09-27T21:27:00Z",
      service = "ping-service",
      circuitBreakerState = "CLOSED",
      responseTime = 42L
    )

    val mockEngine = MockEngine { request ->
      assertEquals("http://localhost:8081/api/ping/enhanced", request.url.encodedPath)
      assertEquals("true", request.url.parameters["simulate"])
      assertEquals(HttpMethod.Get, request.method)

      respond(
        content = Json.encodeToString(EnhancedPingResponse.serializer(), expectedResponse),
        status = HttpStatusCode.OK,
        headers = headersOf(HttpHeaders.ContentType, "application/json")
      )
    }

    // When - This test shows the intended structure
    // val apiClient = PingApiClient(httpClient = HttpClient(mockEngine))
    // val response = apiClient.enhancedPing(simulate = true)

    // Then
    // assertEquals(expectedResponse, response)
  }

  @Test
  fun `healthCheck should return health response`() = runTest {
    // Given
    val expectedResponse = HealthResponse(
      status = "UP",
      timestamp = "2025-09-27T21:27:00Z",
      service = "ping-service",
      healthy = true
    )

    val mockEngine = MockEngine { request ->
      assertEquals("http://localhost:8081/api/ping/health", request.url.toString())
      assertEquals(HttpMethod.Get, request.method)

      respond(
        content = Json.encodeToString(HealthResponse.serializer(), expectedResponse),
        status = HttpStatusCode.OK,
        headers = headersOf(HttpHeaders.ContentType, "application/json")
      )
    }

    // When - Test structure demonstration
    // val apiClient = PingApiClient(httpClient = HttpClient(mockEngine))
    // val response = apiClient.healthCheck()

    // Then
    // assertEquals(expectedResponse, response)
  }

  @Test
  fun `API client should handle HTTP errors correctly`() = runTest {
    val mockEngine = MockEngine { request ->
      respond(
        content = """{"error": "Internal Server Error"}""",
        status = HttpStatusCode.InternalServerError,
        headers = headersOf(HttpHeaders.ContentType, "application/json")
      )
    }

    // Test structure for error handling
    // val apiClient = PingApiClient(httpClient = HttpClient(mockEngine))
    // assertFailsWith<Exception> {
    //     apiClient.simplePing()
    // }
  }

  @Test
  fun `API client should handle network errors`() = runTest {
    val mockEngine = MockEngine { request ->
      throw Exception("Network unreachable")
    }

    // Test structure for network error handling
    // val apiClient = PingApiClient(httpClient = HttpClient(mockEngine))
    // assertFailsWith<Exception> {
    //     apiClient.simplePing()
    // }
  }

  @Test
  fun `JSON serialization should work correctly`() {
    // Given
    val pingResponse = PingResponse(
      status = "OK",
      timestamp = "2025-09-27T21:27:00Z",
      service = "test-service"
    )

    // When
    val json = Json.encodeToString(PingResponse.serializer(), pingResponse)
    val deserializedResponse = Json.decodeFromString(PingResponse.serializer(), json)

    // Then
    assertEquals(pingResponse, deserializedResponse)
  }

  @Test
  fun `Enhanced ping response serialization should work correctly`() {
    // Given
    val enhancedResponse = EnhancedPingResponse(
      status = "OK",
      timestamp = "2025-09-27T21:27:00Z",
      service = "test-service",
      circuitBreakerState = "CLOSED",
      responseTime = 123L
    )

    // When
    val json = Json.encodeToString(EnhancedPingResponse.serializer(), enhancedResponse)
    val deserializedResponse = Json.decodeFromString(EnhancedPingResponse.serializer(), json)

    // Then
    assertEquals(enhancedResponse, deserializedResponse)
  }

  @Test
  fun `Health response serialization should work correctly`() {
    // Given
    val healthResponse = HealthResponse(
      status = "UP",
      timestamp = "2025-09-27T21:27:00Z",
      service = "test-service",
      healthy = true
    )

    // When
    val json = Json.encodeToString(HealthResponse.serializer(), healthResponse)
    val deserializedResponse = Json.decodeFromString(HealthResponse.serializer(), json)

    // Then
    assertEquals(healthResponse, deserializedResponse)
  }

  // Note: The HTTP request tests above demonstrate the test structure but are commented out
  // because the current PingApiClient implementation doesn't support dependency injection
  // of HttpClient. To make these tests fully functional, PingApiClient would need to be
  // refactored to accept HttpClient as a constructor parameter:
  //
  // class PingApiClient(
  //     private val baseUrl: String = "http://localhost:8081",
  //     private val httpClient: HttpClient = HttpClient { ... }
  // )
  //
  // This would enable full HTTP mocking and testing capabilities.
}
