package agent

import (
	"context"
	"log/slog"
	"os"
	"path/filepath"
	"testing"
	"time"

	"github.com/iomodo/staff/git"
	"github.com/iomodo/staff/llm"
	"github.com/iomodo/staff/tm"
	"github.com/iomodo/staff/tm/git_tm"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

// MockLLMProvider implements LLMProvider for testing
type MockLLMProvider struct{}

func (m *MockLLMProvider) ChatCompletion(ctx context.Context, req llm.ChatCompletionRequest) (*llm.ChatCompletionResponse, error) {
	return &llm.ChatCompletionResponse{
		ID:    "mock-response-id",
		Model: req.Model,
		Choices: []llm.ChatCompletionChoice{
			{
				Index: 0,
				Message: llm.Message{
					Role:    llm.RoleAssistant,
					Content: "This is a mock response for testing purposes.",
				},
				FinishReason: "stop",
			},
		},
		Usage: llm.Usage{
			PromptTokens:     10,
			CompletionTokens: 20,
			TotalTokens:      30,
		},
		Provider: llm.ProviderOpenAI,
	}, nil
}

func (m *MockLLMProvider) CreateEmbeddings(ctx context.Context, req llm.EmbeddingRequest) (*llm.EmbeddingResponse, error) {
	return &llm.EmbeddingResponse{
		Object: "list",
		Data: []llm.Embedding{
			{
				Object:    "embedding",
				Embedding: []float64{0.1, 0.2, 0.3},
				Index:     0,
			},
		},
		Usage: llm.Usage{
			PromptTokens: 5,
			TotalTokens:  5,
		},
		Model:    req.Model,
		Provider: llm.ProviderOpenAI,
	}, nil
}

func (m *MockLLMProvider) Close() error {
	return nil
}

// MockLLMFactory implements ProviderFactory for testing
type MockLLMFactory struct{}

func (f *MockLLMFactory) CreateProvider(config llm.Config) (llm.LLMProvider, error) {
	return &MockLLMProvider{}, nil
}

func (f *MockLLMFactory) SupportsProvider(provider llm.Provider) bool {
	return provider == llm.ProviderOpenAI
}

func setupTestAgent(t *testing.T) (*Agent, func()) {
	// Create temporary directories
	tempDir, err := os.MkdirTemp("", "agent-test")
	require.NoError(t, err)

	tasksDir := filepath.Join(tempDir, "tasks")
	workspaceDir := filepath.Join(tempDir, "workspace")
	codeRepoDir := filepath.Join(tempDir, "code-repo")

	// Create directories
	require.NoError(t, os.MkdirAll(tasksDir, 0755))
	require.NoError(t, os.MkdirAll(workspaceDir, 0755))
	require.NoError(t, os.MkdirAll(codeRepoDir, 0755))

	// Initialize git repositories
	gitInterface := git.DefaultGit(tasksDir)
	ctx := context.Background()

	err = gitInterface.Init(ctx, tasksDir)
	require.NoError(t, err)

	// Set git user config
	userConfig := git.UserConfig{
		Name:  "Test User",
		Email: "test@example.com",
	}
	err = gitInterface.SetUserConfig(ctx, userConfig)
	require.NoError(t, err)

	// Create logger for testing
	logger := slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelInfo}))

	// Create task manager
	taskManager := git_tm.NewGitTaskManagerWithLogger(gitInterface, tasksDir, logger)

	// Create LLM config (using a mock configuration)
	llmConfig := llm.Config{
		Provider: llm.ProviderOpenAI,
		APIKey:   "test-key",
		BaseURL:  "https://api.openai.com/v1",
		Timeout:  30 * time.Second,
	}

	// Create agent config
	config := AgentConfig{
		Name:         "test-agent",
		Role:         "Test Engineer",
		GitUsername:  "test-agent",
		GitEmail:     "test-agent@test.com",
		WorkingDir:   workspaceDir,
		LLMProvider:  llm.ProviderOpenAI,
		LLMModel:     "gpt-3.5-turbo",
		LLMConfig:    llmConfig,
		SystemPrompt: "You are a test agent. Provide simple, clear solutions.",
		TaskManager:  taskManager,
		GitRepoPath:  codeRepoDir,
		GitRemote:    "origin",
		GitBranch:    "main",
	}

	// Create logger for testing
	logger = slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelInfo}))

	// Create agent with mock LLM provider
	agent := &Agent{
		Config:       config,
		llmProvider:  &MockLLMProvider{},
		gitInterface: git.DefaultGit(codeRepoDir),
		ctx:          context.Background(),
		cancel:       func() {},
		logger:       logger,
	}

	cleanup := func() {
		agent.Stop()
		os.RemoveAll(tempDir)
	}

	return agent, cleanup
}

func TestNewAgent(t *testing.T) {
	// Create temporary directories
	tempDir, err := os.MkdirTemp("", "agent-test")
	require.NoError(t, err)
	defer os.RemoveAll(tempDir)

	tasksDir := filepath.Join(tempDir, "tasks")
	workspaceDir := filepath.Join(tempDir, "workspace")
	codeRepoDir := filepath.Join(tempDir, "code-repo")

	// Create directories
	require.NoError(t, os.MkdirAll(tasksDir, 0755))
	require.NoError(t, os.MkdirAll(workspaceDir, 0755))
	require.NoError(t, os.MkdirAll(codeRepoDir, 0755))

	// Initialize git repositories
	gitInterface := git.DefaultGit(tasksDir)
	ctx := context.Background()

	err = gitInterface.Init(ctx, tasksDir)
	require.NoError(t, err)

	// Set git user config
	userConfig := git.UserConfig{
		Name:  "Test User",
		Email: "test@example.com",
	}
	err = gitInterface.SetUserConfig(ctx, userConfig)
	require.NoError(t, err)

	// Create logger for testing
	logger := slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelInfo}))

	// Create task manager
	taskManager := git_tm.NewGitTaskManagerWithLogger(gitInterface, tasksDir, logger)

	// Create LLM config (using a mock configuration)
	llmConfig := llm.Config{
		Provider: llm.ProviderOpenAI,
		APIKey:   "test-key",
		BaseURL:  "https://api.openai.com/v1",
		Timeout:  30 * time.Second,
	}

	// Create agent config
	config := AgentConfig{
		Name:         "test-agent",
		Role:         "Test Engineer",
		GitUsername:  "test-agent",
		GitEmail:     "test-agent@test.com",
		WorkingDir:   workspaceDir,
		LLMProvider:  llm.ProviderOpenAI,
		LLMModel:     "gpt-3.5-turbo",
		LLMConfig:    llmConfig,
		SystemPrompt: "You are a test agent. Provide simple, clear solutions.",
		TaskManager:  taskManager,
		GitRepoPath:  codeRepoDir,
		GitRemote:    "origin",
		GitBranch:    "main",
	}

	// Create logger for testing
	logger = slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelInfo}))

	// Create agent using NewAgent function
	agent, err := NewAgent(config, logger)
	require.NoError(t, err)
	defer agent.Stop()

	assert.NotNil(t, agent)
	assert.Equal(t, "test-agent", agent.Config.Name)
	assert.Equal(t, "Test Engineer", agent.Config.Role)
}

func TestValidateConfig(t *testing.T) {
	// Test valid config
	validConfig := AgentConfig{
		Name:         "test",
		Role:         "test",
		WorkingDir:   "/tmp",
		SystemPrompt: "test",
		TaskManager:  &git_tm.GitTaskManager{},
		GitRepoPath:  "/tmp",
	}

	err := validateConfig(validConfig)
	assert.NoError(t, err)

	// Test invalid configs
	testCases := []struct {
		name   string
		config AgentConfig
	}{
		{"empty name", AgentConfig{Role: "test", WorkingDir: "/tmp", SystemPrompt: "test", TaskManager: &git_tm.GitTaskManager{}, GitRepoPath: "/tmp"}},
		{"empty role", AgentConfig{Name: "test", WorkingDir: "/tmp", SystemPrompt: "test", TaskManager: &git_tm.GitTaskManager{}, GitRepoPath: "/tmp"}},
		{"empty working dir", AgentConfig{Name: "test", Role: "test", SystemPrompt: "test", TaskManager: &git_tm.GitTaskManager{}, GitRepoPath: "/tmp"}},
		{"empty system prompt", AgentConfig{Name: "test", Role: "test", WorkingDir: "/tmp", SystemPrompt: "test", GitRepoPath: "/tmp"}},
		{"nil task manager", AgentConfig{Name: "test", Role: "test", WorkingDir: "/tmp", SystemPrompt: "test", GitRepoPath: "/tmp"}},
		{"empty git repo path", AgentConfig{Name: "test", Role: "test", WorkingDir: "/tmp", SystemPrompt: "test", TaskManager: &git_tm.GitTaskManager{}}},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			err := validateConfig(tc.config)
			assert.Error(t, err)
		})
	}
}

func TestGenerateBranchName(t *testing.T) {
	agent, cleanup := setupTestAgent(t)
	defer cleanup()

	task := &tm.Task{
		ID:    "task-123",
		Title: "Implement User Authentication",
	}

	branchName := agent.generateBranchName(task)
	assert.Contains(t, branchName, "task-123")
	assert.Contains(t, branchName, "implement-user-authentication")
}

func TestBuildTaskPrompt(t *testing.T) {
	agent, cleanup := setupTestAgent(t)
	defer cleanup()

	dueDate := time.Now().AddDate(0, 0, 7)
	task := &tm.Task{
		ID:          "task-123",
		Title:       "Test Task",
		Description: "This is a test task",
		Priority:    tm.PriorityHigh,
		DueDate:     &dueDate,
	}

	prompt := agent.buildTaskPrompt(task)
	assert.Contains(t, prompt, "task-123")
	assert.Contains(t, prompt, "Test Task")
	assert.Contains(t, prompt, "This is a test task")
	assert.Contains(t, prompt, "high")
}

func TestFormatSolution(t *testing.T) {
	agent, cleanup := setupTestAgent(t)
	defer cleanup()

	task := &tm.Task{
		ID:          "task-123",
		Title:       "Test Task",
		Description: "This is a test task description",
		Priority:    tm.PriorityMedium,
	}

	solution := "This is the solution to the task."
	formatted := agent.formatSolution(task, solution)

	assert.Contains(t, formatted, "# Task Solution: Test Task")
	assert.Contains(t, formatted, "**Task ID:** task-123")
	assert.Contains(t, formatted, "**Agent:** test-agent (Test Engineer)")
	assert.Contains(t, formatted, "## Task Description")
	assert.Contains(t, formatted, "This is a test task description")
	assert.Contains(t, formatted, "## Solution")
	assert.Contains(t, formatted, "This is the solution to the task.")
	assert.Contains(t, formatted, "*This solution was generated by AI Agent*")
}

func TestAgentStop(t *testing.T) {
	agent, cleanup := setupTestAgent(t)
	defer cleanup()

	// Test that Stop doesn't panic
	assert.NotPanics(t, func() {
		agent.Stop()
	})
}

func TestGenerateBranchNameWithSpecialCharacters(t *testing.T) {
	agent, cleanup := setupTestAgent(t)
	defer cleanup()

	testCases := []struct {
		title    string
		expected string
	}{
		{
			title:    "Simple Task",
			expected: "task/task-123-simple-task",
		},
		{
			title:    "Task with (parentheses) and [brackets]",
			expected: "task/task-123-task-with-parentheses-and-brackets",
		},
		{
			title:    "Very Long Task Title That Should Be Truncated Because It Exceeds The Maximum Length Allowed For Branch Names",
			expected: "task/task-123-very-long-task-title-that-should-be-truncated-beca",
		},
	}

	for _, tc := range testCases {
		t.Run(tc.title, func(t *testing.T) {
			task := &tm.Task{
				ID:    "task-123",
				Title: tc.title,
			}

			branchName := agent.generateBranchName(task)
			assert.Equal(t, tc.expected, branchName)
		})
	}
}

func TestProcessTaskWithLLM(t *testing.T) {
	agent, cleanup := setupTestAgent(t)
	defer cleanup()

	task := &tm.Task{
		ID:          "task-123",
		Title:       "Test Task",
		Description: "This is a test task",
		Priority:    tm.PriorityHigh,
	}

	solution, err := agent.processTaskWithLLM(task)
	assert.NoError(t, err)
	assert.Contains(t, solution, "mock response")
}

func TestMockLLMProvider(t *testing.T) {
	mockProvider := &MockLLMProvider{}

	// Test ChatCompletion
	req := llm.ChatCompletionRequest{
		Model: "gpt-3.5-turbo",
		Messages: []llm.Message{
			{Role: llm.RoleUser, Content: "Hello"},
		},
	}

	resp, err := mockProvider.ChatCompletion(context.Background(), req)
	assert.NoError(t, err)
	assert.NotNil(t, resp)
	assert.Equal(t, "gpt-3.5-turbo", resp.Model)
	assert.Len(t, resp.Choices, 1)
	assert.Contains(t, resp.Choices[0].Message.Content, "mock response")

	// Test CreateEmbeddings
	embedReq := llm.EmbeddingRequest{
		Input: "test",
		Model: "text-embedding-ada-002",
	}

	embedResp, err := mockProvider.CreateEmbeddings(context.Background(), embedReq)
	assert.NoError(t, err)
	assert.NotNil(t, embedResp)
	assert.Len(t, embedResp.Data, 1)
	assert.Len(t, embedResp.Data[0].Embedding, 3)

	// Test Close
	err = mockProvider.Close()
	assert.NoError(t, err)
}