package controller

import (
	"context"
	"encoding/json"
	"errors"
	"testing"

	"hash-of-wisdom/internal/controller/mocks"
	"hash-of-wisdom/internal/pow/challenge"
	"hash-of-wisdom/internal/protocol"
	"hash-of-wisdom/internal/quotes"
	"hash-of-wisdom/internal/service"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/mock"
	"github.com/stretchr/testify/require"
)

func TestNewWisdomController(t *testing.T) {
	mockService := mocks.NewMockWisdomService(t)
	controller := NewWisdomController(mockService)

	assert.NotNil(t, controller)
	assert.Equal(t, mockService, controller.wisdomService)
	assert.NotNil(t, controller.codec)
}

func TestWisdomController_HandleMessage_UnsupportedType(t *testing.T) {
	mockService := mocks.NewMockWisdomService(t)
	controller := NewWisdomController(mockService)

	ctx := context.Background()
	msg := &protocol.Message{
		Type:    protocol.MessageType(0xFF), // Invalid type
		Payload: []byte{},
	}

	response, err := controller.HandleMessage(ctx, msg)
	require.NoError(t, err)
	assert.Equal(t, protocol.ErrorResponse, response.Type)

	var errorPayload protocol.ErrorResponsePayload
	err = json.Unmarshal(response.Payload, &errorPayload)
	require.NoError(t, err)
	assert.Equal(t, protocol.ErrMalformedMessage, errorPayload.Code)
	assert.Contains(t, errorPayload.Message, "unsupported message type: 0xff")
}

func TestWisdomController_HandleChallengeRequest_Success(t *testing.T) {
	mockService := mocks.NewMockWisdomService(t)
	controller := NewWisdomController(mockService)

	// Mock successful challenge generation
	testChallenge := &challenge.Challenge{
		Resource:   "quotes",
		Timestamp:  12345,
		Difficulty: 4,
		Random:     []byte("test"),
		HMAC:       []byte("signature"),
	}

	mockService.On("GenerateChallenge", mock.Anything, "quotes").Return(testChallenge, nil)

	ctx := context.Background()
	msg := &protocol.Message{
		Type:    protocol.ChallengeRequest,
		Payload: []byte{},
	}

	response, err := controller.HandleMessage(ctx, msg)
	require.NoError(t, err)
	assert.Equal(t, protocol.ChallengeResponse, response.Type)

	// Verify the challenge is properly marshaled
	var challengePayload challenge.Challenge
	err = json.Unmarshal(response.Payload, &challengePayload)
	require.NoError(t, err)
	assert.Equal(t, testChallenge.Resource, challengePayload.Resource)
	assert.Equal(t, testChallenge.Difficulty, challengePayload.Difficulty)

	mockService.AssertExpectations(t)
}

func TestWisdomController_HandleChallengeRequest_ServiceError(t *testing.T) {
	mockService := mocks.NewMockWisdomService(t)
	controller := NewWisdomController(mockService)

	// Mock service error
	mockService.On("GenerateChallenge", mock.Anything, "quotes").Return(nil, errors.New("service error"))

	ctx := context.Background()
	msg := &protocol.Message{
		Type:    protocol.ChallengeRequest,
		Payload: []byte{},
	}

	response, err := controller.HandleMessage(ctx, msg)
	require.NoError(t, err)
	assert.Equal(t, protocol.ErrorResponse, response.Type)

	var errorPayload protocol.ErrorResponsePayload
	err = json.Unmarshal(response.Payload, &errorPayload)
	require.NoError(t, err)
	assert.Equal(t, protocol.ErrServerError, errorPayload.Code)
	assert.Equal(t, "failed to generate challenge", errorPayload.Message)

	mockService.AssertExpectations(t)
}

func TestWisdomController_HandleSolutionRequest_Success(t *testing.T) {
	mockService := mocks.NewMockWisdomService(t)
	controller := NewWisdomController(mockService)

	// Create test solution request
	testChallenge := challenge.Challenge{
		Resource:   "quotes",
		Timestamp:  12345,
		Difficulty: 4,
		Random:     []byte("test"),
		HMAC:       []byte("signature"),
	}

	solutionPayload := protocol.SolutionRequestPayload{
		Challenge: testChallenge,
		Nonce:     12345,
	}

	payloadJSON, err := json.Marshal(solutionPayload)
	require.NoError(t, err)

	testQuote := &quotes.Quote{
		Text:   "Test quote",
		Author: "Test Author",
	}

	// Mock successful verification and quote retrieval
	mockService.On("VerifySolution", mock.Anything, mock.AnythingOfType("*challenge.Solution")).Return(nil)
	mockService.On("GetQuote", mock.Anything).Return(testQuote, nil)

	ctx := context.Background()
	msg := &protocol.Message{
		Type:    protocol.SolutionRequest,
		Payload: payloadJSON,
	}

	response, err := controller.HandleMessage(ctx, msg)
	require.NoError(t, err)
	assert.Equal(t, protocol.QuoteResponse, response.Type)

	// Verify the quote is properly marshaled
	var quotePayload quotes.Quote
	err = json.Unmarshal(response.Payload, &quotePayload)
	require.NoError(t, err)
	assert.Equal(t, testQuote.Text, quotePayload.Text)
	assert.Equal(t, testQuote.Author, quotePayload.Author)

	mockService.AssertExpectations(t)
}

func TestWisdomController_HandleSolutionRequest_InvalidJSON(t *testing.T) {
	mockService := mocks.NewMockWisdomService(t)
	controller := NewWisdomController(mockService)

	ctx := context.Background()
	msg := &protocol.Message{
		Type:    protocol.SolutionRequest,
		Payload: []byte("invalid json"),
	}

	response, err := controller.HandleMessage(ctx, msg)
	require.NoError(t, err)
	assert.Equal(t, protocol.ErrorResponse, response.Type)

	var errorPayload protocol.ErrorResponsePayload
	err = json.Unmarshal(response.Payload, &errorPayload)
	require.NoError(t, err)
	assert.Equal(t, protocol.ErrMalformedMessage, errorPayload.Code)
	assert.Equal(t, "invalid solution format", errorPayload.Message)

	mockService.AssertNotCalled(t, "VerifySolution")
	mockService.AssertNotCalled(t, "GetQuote")
}

func TestWisdomController_HandleSolutionRequest_VerificationFailed(t *testing.T) {
	mockService := mocks.NewMockWisdomService(t)
	controller := NewWisdomController(mockService)

	// Create test solution request
	testChallenge := challenge.Challenge{
		Resource:   "quotes",
		Timestamp:  12345,
		Difficulty: 4,
		Random:     []byte("test"),
		HMAC:       []byte("signature"),
	}

	solutionPayload := protocol.SolutionRequestPayload{
		Challenge: testChallenge,
		Nonce:     12345,
	}

	payloadJSON, err := json.Marshal(solutionPayload)
	require.NoError(t, err)

	// Mock verification failure
	mockService.On("VerifySolution", mock.Anything, mock.AnythingOfType("*challenge.Solution")).Return(service.ErrInvalidSolution)

	ctx := context.Background()
	msg := &protocol.Message{
		Type:    protocol.SolutionRequest,
		Payload: payloadJSON,
	}

	response, err := controller.HandleMessage(ctx, msg)
	require.NoError(t, err)
	assert.Equal(t, protocol.ErrorResponse, response.Type)

	var errorPayload protocol.ErrorResponsePayload
	err = json.Unmarshal(response.Payload, &errorPayload)
	require.NoError(t, err)
	assert.Equal(t, protocol.ErrInvalidSolution, errorPayload.Code)
	assert.Equal(t, "solution verification failed", errorPayload.Message)

	mockService.AssertExpectations(t)
	mockService.AssertNotCalled(t, "GetQuote")
}

func TestWisdomController_HandleSolutionRequest_QuoteServiceError(t *testing.T) {
	mockService := mocks.NewMockWisdomService(t)
	controller := NewWisdomController(mockService)

	// Create test solution request
	testChallenge := challenge.Challenge{
		Resource:   "quotes",
		Timestamp:  12345,
		Difficulty: 4,
		Random:     []byte("test"),
		HMAC:       []byte("signature"),
	}

	solutionPayload := protocol.SolutionRequestPayload{
		Challenge: testChallenge,
		Nonce:     12345,
	}

	payloadJSON, err := json.Marshal(solutionPayload)
	require.NoError(t, err)

	// Mock successful verification but quote service error
	mockService.On("VerifySolution", mock.Anything, mock.AnythingOfType("*challenge.Solution")).Return(nil)
	mockService.On("GetQuote", mock.Anything).Return(nil, errors.New("quote service error"))

	ctx := context.Background()
	msg := &protocol.Message{
		Type:    protocol.SolutionRequest,
		Payload: payloadJSON,
	}

	response, err := controller.HandleMessage(ctx, msg)
	require.NoError(t, err)
	assert.Equal(t, protocol.ErrorResponse, response.Type)

	var errorPayload protocol.ErrorResponsePayload
	err = json.Unmarshal(response.Payload, &errorPayload)
	require.NoError(t, err)
	assert.Equal(t, protocol.ErrServerError, errorPayload.Code)
	assert.Equal(t, "failed to get quote", errorPayload.Message)

	mockService.AssertExpectations(t)
}

func TestWisdomController_CreateErrorResponse_MarshalError(t *testing.T) {
	mockService := mocks.NewMockWisdomService(t)
	controller := NewWisdomController(mockService)

	// This test verifies the internal error handling
	// In practice, json.Marshal on ErrorResponsePayload should never fail
	// But we test the error path for completeness
	response, err := controller.createErrorResponse(protocol.ErrServerError, "test message")

	// Should not fail with normal inputs
	require.NoError(t, err)
	assert.Equal(t, protocol.ErrorResponse, response.Type)
	assert.NotEmpty(t, response.Payload)
}

func TestWisdomController_HandleMessage_ContextCancellation(t *testing.T) {
	mockService := mocks.NewMockWisdomService(t)
	controller := NewWisdomController(mockService)

	// Create cancelled context
	ctx, cancel := context.WithCancel(context.Background())
	cancel()

	// Mock service to respect context cancellation
	mockService.On("GenerateChallenge", mock.Anything, "quotes").Return(nil, context.Canceled)

	msg := &protocol.Message{
		Type:    protocol.ChallengeRequest,
		Payload: []byte{},
	}

	response, err := controller.HandleMessage(ctx, msg)
	require.NoError(t, err)
	assert.Equal(t, protocol.ErrorResponse, response.Type)

	var errorPayload protocol.ErrorResponsePayload
	err = json.Unmarshal(response.Payload, &errorPayload)
	require.NoError(t, err)
	assert.Equal(t, protocol.ErrServerError, errorPayload.Code)

	mockService.AssertExpectations(t)
}