package ai

import (
	"context"
	"testing"
	"time"

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

// MockProvider implements ModelProvider for testing
type MockProvider struct {
	name         string
	capabilities ProviderCapabilities
	shouldFail   bool
	response     *TaskResponse
	executeFunc  func(ctx context.Context, request *TaskRequest) (*TaskResponse, error)
}

func NewMockProvider(name string) *MockProvider {
	return &MockProvider{
		name: name,
		capabilities: ProviderCapabilities{
			SupportsMCP:       true,
			SupportsTools:     true,
			SupportsStreaming: true,
			SupportsFunctions: false,
			MaxTokens:         4096,
			SupportedModels:   []string{"test-model", "test-model-2"},
			SupportsImages:    false,
			SupportsFiles:     true,
		},
		response: &TaskResponse{
			Success:  true,
			Response: "Mock response",
		},
	}
}

func (m *MockProvider) ExecuteTask(ctx context.Context, request *TaskRequest) (*TaskResponse, error) {
	if m.executeFunc != nil {
		return m.executeFunc(ctx, request)
	}

	if m.shouldFail {
		return nil, NewProviderError(ErrTaskExecutionFailed, "mock execution failed")
	}

	response := *m.response // Copy the response
	response.TaskID = request.TaskID
	response.AgentID = request.AgentID
	response.Provider = m.name
	response.StartTime = time.Now()
	response.EndTime = time.Now().Add(100 * time.Millisecond)
	response.Duration = response.EndTime.Sub(response.StartTime)

	return &response, nil
}

func (m *MockProvider) GetCapabilities() ProviderCapabilities {
	return m.capabilities
}

func (m *MockProvider) ValidateConfig() error {
	if m.shouldFail {
		return NewProviderError(ErrInvalidConfiguration, "mock config validation failed")
	}
	return nil
}

func (m *MockProvider) GetProviderInfo() ProviderInfo {
	return ProviderInfo{
		Name:           m.name,
		Type:           "mock",
		Version:        "1.0.0",
		Endpoint:       "mock://localhost",
		DefaultModel:   "test-model",
		RequiresAPIKey: false,
		RateLimit:      0,
	}
}

func TestProviderError(t *testing.T) {
	tests := []struct {
		name      string
		err       *ProviderError
		expected  string
		retryable bool
	}{
		{
			name:      "simple error",
			err:       ErrProviderNotFound,
			expected:  "Provider not found",
			retryable: false,
		},
		{
			name:      "error with details",
			err:       NewProviderError(ErrRateLimitExceeded, "API rate limit of 1000/hour exceeded"),
			expected:  "Rate limit exceeded: API rate limit of 1000/hour exceeded",
			retryable: false,
		},
		{
			name: "retryable error",
			err: &ProviderError{
				Code:      "TEMPORARY_ERROR",
				Message:   "Temporary failure",
				Retryable: true,
			},
			expected:  "Temporary failure",
			retryable: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			assert.Equal(t, tt.expected, tt.err.Error())
			assert.Equal(t, tt.retryable, tt.err.IsRetryable())
		})
	}
}

func TestTaskRequest(t *testing.T) {
	request := &TaskRequest{
		TaskID:          "test-task-123",
		AgentID:         "agent-456",
		AgentRole:       "developer",
		Repository:      "test/repo",
		TaskTitle:       "Test Task",
		TaskDescription: "A test task for unit testing",
		TaskLabels:      []string{"bug", "urgent"},
		Priority:        8,
		Complexity:      6,
		ModelName:       "test-model",
		Temperature:     0.7,
		MaxTokens:       4096,
		EnableTools:     true,
	}

	// Validate required fields
	assert.NotEmpty(t, request.TaskID)
	assert.NotEmpty(t, request.AgentID)
	assert.NotEmpty(t, request.AgentRole)
	assert.NotEmpty(t, request.Repository)
	assert.NotEmpty(t, request.TaskTitle)
	assert.Greater(t, request.Priority, 0)
	assert.Greater(t, request.Complexity, 0)
}

func TestTaskResponse(t *testing.T) {
	startTime := time.Now()
	endTime := startTime.Add(2 * time.Second)

	response := &TaskResponse{
		Success:   true,
		TaskID:    "test-task-123",
		AgentID:   "agent-456",
		ModelUsed: "test-model",
		Provider:  "mock",
		Response:  "Task completed successfully",
		Actions: []TaskAction{
			{
				Type:      "file_create",
				Target:    "test.go",
				Content:   "package main",
				Result:    "File created",
				Success:   true,
				Timestamp: time.Now(),
			},
		},
		Artifacts: []Artifact{
			{
				Name:      "test.go",
				Type:      "file",
				Path:      "./test.go",
				Content:   "package main",
				Size:      12,
				CreatedAt: time.Now(),
			},
		},
		StartTime: startTime,
		EndTime:   endTime,
		Duration:  endTime.Sub(startTime),
		TokensUsed: TokenUsage{
			PromptTokens:     50,
			CompletionTokens: 100,
			TotalTokens:      150,
		},
	}

	// Validate response structure
	assert.True(t, response.Success)
	assert.NotEmpty(t, response.TaskID)
	assert.NotEmpty(t, response.Provider)
	assert.Len(t, response.Actions, 1)
	assert.Len(t, response.Artifacts, 1)
	assert.Equal(t, 2*time.Second, response.Duration)
	assert.Equal(t, 150, response.TokensUsed.TotalTokens)
}

func TestTaskAction(t *testing.T) {
	action := TaskAction{
		Type:      "file_edit",
		Target:    "main.go",
		Content:   "updated content",
		Result:    "File updated successfully",
		Success:   true,
		Timestamp: time.Now(),
		Metadata: map[string]interface{}{
			"line_count": 42,
			"backup":     true,
		},
	}

	assert.Equal(t, "file_edit", action.Type)
	assert.True(t, action.Success)
	assert.NotNil(t, action.Metadata)
	assert.Equal(t, 42, action.Metadata["line_count"])
}

func TestArtifact(t *testing.T) {
	artifact := Artifact{
		Name:      "output.log",
		Type:      "log",
		Path:      "/tmp/output.log",
		Content:   "Log content here",
		Size:      16,
		CreatedAt: time.Now(),
		Checksum:  "abc123",
	}

	assert.Equal(t, "output.log", artifact.Name)
	assert.Equal(t, "log", artifact.Type)
	assert.Equal(t, int64(16), artifact.Size)
	assert.NotEmpty(t, artifact.Checksum)
}

func TestProviderCapabilities(t *testing.T) {
	capabilities := ProviderCapabilities{
		SupportsMCP:       true,
		SupportsTools:     true,
		SupportsStreaming: false,
		SupportsFunctions: true,
		MaxTokens:         8192,
		SupportedModels:   []string{"gpt-4", "gpt-3.5-turbo"},
		SupportsImages:    true,
		SupportsFiles:     true,
	}

	assert.True(t, capabilities.SupportsMCP)
	assert.True(t, capabilities.SupportsTools)
	assert.False(t, capabilities.SupportsStreaming)
	assert.Equal(t, 8192, capabilities.MaxTokens)
	assert.Len(t, capabilities.SupportedModels, 2)
}

func TestProviderInfo(t *testing.T) {
	info := ProviderInfo{
		Name:           "Test Provider",
		Type:           "test",
		Version:        "1.0.0",
		Endpoint:       "https://api.test.com",
		DefaultModel:   "test-model",
		RequiresAPIKey: true,
		RateLimit:      1000,
	}

	assert.Equal(t, "Test Provider", info.Name)
	assert.True(t, info.RequiresAPIKey)
	assert.Equal(t, 1000, info.RateLimit)
}

func TestProviderConfig(t *testing.T) {
	config := ProviderConfig{
		Type:          "test",
		Endpoint:      "https://api.test.com",
		APIKey:        "test-key",
		DefaultModel:  "test-model",
		Temperature:   0.7,
		MaxTokens:     4096,
		Timeout:       300 * time.Second,
		RetryAttempts: 3,
		RetryDelay:    2 * time.Second,
		EnableTools:   true,
		EnableMCP:     true,
	}

	assert.Equal(t, "test", config.Type)
	assert.Equal(t, float32(0.7), config.Temperature)
	assert.Equal(t, 4096, config.MaxTokens)
	assert.Equal(t, 300*time.Second, config.Timeout)
	assert.True(t, config.EnableTools)
}

func TestRoleConfig(t *testing.T) {
	roleConfig := RoleConfig{
		Provider:         "openai",
		Model:           "gpt-4",
		Temperature:     0.3,
		MaxTokens:       8192,
		SystemPrompt:    "You are a helpful assistant",
		FallbackProvider: "ollama",
		FallbackModel:   "llama2",
		EnableTools:     true,
		EnableMCP:       false,
		AllowedTools:    []string{"file_ops", "code_analysis"},
		MCPServers:      []string{"file-server"},
	}

	assert.Equal(t, "openai", roleConfig.Provider)
	assert.Equal(t, "gpt-4", roleConfig.Model)
	assert.Equal(t, float32(0.3), roleConfig.Temperature)
	assert.Len(t, roleConfig.AllowedTools, 2)
	assert.True(t, roleConfig.EnableTools)
	assert.False(t, roleConfig.EnableMCP)
}

func TestRoleModelMapping(t *testing.T) {
	mapping := RoleModelMapping{
		DefaultProvider:  "ollama",
		FallbackProvider: "openai",
		Roles: map[string]RoleConfig{
			"developer": {
				Provider:    "ollama",
				Model:      "codellama",
				Temperature: 0.3,
			},
			"reviewer": {
				Provider:    "openai",
				Model:      "gpt-4",
				Temperature: 0.2,
			},
		},
	}

	assert.Equal(t, "ollama", mapping.DefaultProvider)
	assert.Len(t, mapping.Roles, 2)

	devConfig, exists := mapping.Roles["developer"]
	require.True(t, exists)
	assert.Equal(t, "codellama", devConfig.Model)
	assert.Equal(t, float32(0.3), devConfig.Temperature)
}

func TestTokenUsage(t *testing.T) {
	usage := TokenUsage{
		PromptTokens:     100,
		CompletionTokens: 200,
		TotalTokens:      300,
	}

	assert.Equal(t, 100, usage.PromptTokens)
	assert.Equal(t, 200, usage.CompletionTokens)
	assert.Equal(t, 300, usage.TotalTokens)
	assert.Equal(t, usage.PromptTokens+usage.CompletionTokens, usage.TotalTokens)
}

func TestMockProviderExecuteTask(t *testing.T) {
	provider := NewMockProvider("test-provider")

	request := &TaskRequest{
		TaskID:    "test-123",
		AgentID:   "agent-456",
		AgentRole: "developer",
		Repository: "test/repo",
		TaskTitle: "Test Task",
	}

	ctx := context.Background()
	response, err := provider.ExecuteTask(ctx, request)

	require.NoError(t, err)
	assert.True(t, response.Success)
	assert.Equal(t, "test-123", response.TaskID)
	assert.Equal(t, "agent-456", response.AgentID)
	assert.Equal(t, "test-provider", response.Provider)
	assert.NotEmpty(t, response.Response)
}

func TestMockProviderFailure(t *testing.T) {
	provider := NewMockProvider("failing-provider")
	provider.shouldFail = true

	request := &TaskRequest{
		TaskID:    "test-123",
		AgentID:   "agent-456",
		AgentRole: "developer",
	}

	ctx := context.Background()
	_, err := provider.ExecuteTask(ctx, request)

	require.Error(t, err)
	assert.IsType(t, &ProviderError{}, err)

	providerErr := err.(*ProviderError)
	assert.Equal(t, "TASK_EXECUTION_FAILED", providerErr.Code)
}

func TestMockProviderCustomExecuteFunc(t *testing.T) {
	provider := NewMockProvider("custom-provider")

	// Set custom execution function
	provider.executeFunc = func(ctx context.Context, request *TaskRequest) (*TaskResponse, error) {
		return &TaskResponse{
			Success:  true,
			TaskID:   request.TaskID,
			Response: "Custom response: " + request.TaskTitle,
			Provider: "custom-provider",
		}, nil
	}

	request := &TaskRequest{
		TaskID:    "test-123",
		TaskTitle: "Custom Task",
	}

	ctx := context.Background()
	response, err := provider.ExecuteTask(ctx, request)

	require.NoError(t, err)
	assert.Equal(t, "Custom response: Custom Task", response.Response)
}

func TestMockProviderCapabilities(t *testing.T) {
	provider := NewMockProvider("test-provider")

	capabilities := provider.GetCapabilities()

	assert.True(t, capabilities.SupportsMCP)
	assert.True(t, capabilities.SupportsTools)
	assert.Equal(t, 4096, capabilities.MaxTokens)
	assert.Len(t, capabilities.SupportedModels, 2)
	assert.Contains(t, capabilities.SupportedModels, "test-model")
}

func TestMockProviderInfo(t *testing.T) {
	provider := NewMockProvider("test-provider")

	info := provider.GetProviderInfo()

	assert.Equal(t, "test-provider", info.Name)
	assert.Equal(t, "mock", info.Type)
	assert.Equal(t, "test-model", info.DefaultModel)
	assert.False(t, info.RequiresAPIKey)
}