package ai

import (
	"context"
	"testing"
	"time"

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

func TestNewProviderFactory(t *testing.T) {
	factory := NewProviderFactory()

	assert.NotNil(t, factory)
	assert.Empty(t, factory.configs)
	assert.Empty(t, factory.providers)
	assert.Empty(t, factory.healthChecks)
	assert.Empty(t, factory.lastHealthCheck)
}

func TestProviderFactoryRegisterProvider(t *testing.T) {
	factory := NewProviderFactory()

	// Create a valid mock provider config (since validation will be called)
	config := ProviderConfig{
		Type:         "mock",
		Endpoint:     "mock://localhost",
		DefaultModel: "test-model",
		Temperature:  0.7,
		MaxTokens:    4096,
		Timeout:      300 * time.Second,
	}

	// Override CreateProvider to return our mock
	originalCreate := factory.CreateProvider
	factory.CreateProvider = func(config ProviderConfig) (ModelProvider, error) {
		return NewMockProvider("test-provider"), nil
	}
	defer func() { factory.CreateProvider = originalCreate }()

	err := factory.RegisterProvider("test", config)
	require.NoError(t, err)

	// Verify provider was registered
	assert.Len(t, factory.providers, 1)
	assert.Contains(t, factory.providers, "test")
	assert.True(t, factory.healthChecks["test"])
}

func TestProviderFactoryRegisterProviderValidationFailure(t *testing.T) {
	factory := NewProviderFactory()

	// Create a mock provider that will fail validation
	config := ProviderConfig{
		Type:         "mock",
		Endpoint:     "mock://localhost",
		DefaultModel: "test-model",
	}

	// Override CreateProvider to return a failing mock
	factory.CreateProvider = func(config ProviderConfig) (ModelProvider, error) {
		mock := NewMockProvider("failing-provider")
		mock.shouldFail = true // This will make ValidateConfig fail
		return mock, nil
	}

	err := factory.RegisterProvider("failing", config)
	require.Error(t, err)
	assert.Contains(t, err.Error(), "invalid configuration")

	// Verify provider was not registered
	assert.Empty(t, factory.providers)
}

func TestProviderFactoryGetProvider(t *testing.T) {
	factory := NewProviderFactory()
	mockProvider := NewMockProvider("test-provider")

	// Manually add provider and mark as healthy
	factory.providers["test"] = mockProvider
	factory.healthChecks["test"] = true
	factory.lastHealthCheck["test"] = time.Now()

	provider, err := factory.GetProvider("test")
	require.NoError(t, err)
	assert.Equal(t, mockProvider, provider)
}

func TestProviderFactoryGetProviderNotFound(t *testing.T) {
	factory := NewProviderFactory()

	_, err := factory.GetProvider("nonexistent")
	require.Error(t, err)
	assert.IsType(t, &ProviderError{}, err)

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

func TestProviderFactoryGetProviderUnhealthy(t *testing.T) {
	factory := NewProviderFactory()
	mockProvider := NewMockProvider("test-provider")

	// Add provider but mark as unhealthy
	factory.providers["test"] = mockProvider
	factory.healthChecks["test"] = false
	factory.lastHealthCheck["test"] = time.Now()

	_, err := factory.GetProvider("test")
	require.Error(t, err)
	assert.IsType(t, &ProviderError{}, err)

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

func TestProviderFactorySetRoleMapping(t *testing.T) {
	factory := NewProviderFactory()

	mapping := RoleModelMapping{
		DefaultProvider:  "test",
		FallbackProvider: "backup",
		Roles: map[string]RoleConfig{
			"developer": {
				Provider: "test",
				Model:   "dev-model",
			},
		},
	}

	factory.SetRoleMapping(mapping)

	assert.Equal(t, mapping, factory.roleMapping)
}

func TestProviderFactoryGetProviderForRole(t *testing.T) {
	factory := NewProviderFactory()

	// Set up providers
	devProvider := NewMockProvider("dev-provider")
	backupProvider := NewMockProvider("backup-provider")

	factory.providers["dev"] = devProvider
	factory.providers["backup"] = backupProvider
	factory.healthChecks["dev"] = true
	factory.healthChecks["backup"] = true
	factory.lastHealthCheck["dev"] = time.Now()
	factory.lastHealthCheck["backup"] = time.Now()

	factory.configs["dev"] = ProviderConfig{
		Type:         "mock",
		DefaultModel: "dev-model",
		Temperature:  0.7,
	}

	factory.configs["backup"] = ProviderConfig{
		Type:         "mock",
		DefaultModel: "backup-model",
		Temperature:  0.8,
	}

	// Set up role mapping
	mapping := RoleModelMapping{
		DefaultProvider:  "backup",
		FallbackProvider: "backup",
		Roles: map[string]RoleConfig{
			"developer": {
				Provider:    "dev",
				Model:      "custom-dev-model",
				Temperature: 0.3,
			},
		},
	}
	factory.SetRoleMapping(mapping)

	provider, config, err := factory.GetProviderForRole("developer")
	require.NoError(t, err)

	assert.Equal(t, devProvider, provider)
	assert.Equal(t, "custom-dev-model", config.DefaultModel)
	assert.Equal(t, float32(0.3), config.Temperature)
}

func TestProviderFactoryGetProviderForRoleWithFallback(t *testing.T) {
	factory := NewProviderFactory()

	// Set up only backup provider (primary is missing)
	backupProvider := NewMockProvider("backup-provider")
	factory.providers["backup"] = backupProvider
	factory.healthChecks["backup"] = true
	factory.lastHealthCheck["backup"] = time.Now()
	factory.configs["backup"] = ProviderConfig{Type: "mock", DefaultModel: "backup-model"}

	// Set up role mapping with primary provider that doesn't exist
	mapping := RoleModelMapping{
		DefaultProvider:  "backup",
		FallbackProvider: "backup",
		Roles: map[string]RoleConfig{
			"developer": {
				Provider:         "nonexistent",
				FallbackProvider: "backup",
			},
		},
	}
	factory.SetRoleMapping(mapping)

	provider, config, err := factory.GetProviderForRole("developer")
	require.NoError(t, err)

	assert.Equal(t, backupProvider, provider)
	assert.Equal(t, "backup-model", config.DefaultModel)
}

func TestProviderFactoryGetProviderForRoleNotFound(t *testing.T) {
	factory := NewProviderFactory()

	// No providers registered and no default
	mapping := RoleModelMapping{
		Roles: make(map[string]RoleConfig),
	}
	factory.SetRoleMapping(mapping)

	_, _, err := factory.GetProviderForRole("nonexistent")
	require.Error(t, err)
	assert.IsType(t, &ProviderError{}, err)
}

func TestProviderFactoryGetProviderForTask(t *testing.T) {
	factory := NewProviderFactory()

	// Set up a provider that supports a specific model
	mockProvider := NewMockProvider("test-provider")
	mockProvider.capabilities.SupportedModels = []string{"specific-model", "another-model"}

	factory.providers["test"] = mockProvider
	factory.healthChecks["test"] = true
	factory.lastHealthCheck["test"] = time.Now()
	factory.configs["test"] = ProviderConfig{Type: "mock", DefaultModel: "default-model"}

	request := &TaskRequest{
		TaskID:    "test-123",
		AgentRole: "developer",
		ModelName: "specific-model", // Request specific model
	}

	provider, config, err := factory.GetProviderForTask(request)
	require.NoError(t, err)

	assert.Equal(t, mockProvider, provider)
	assert.Equal(t, "specific-model", config.DefaultModel) // Should override default
}

func TestProviderFactoryGetProviderForTaskModelNotSupported(t *testing.T) {
	factory := NewProviderFactory()

	mockProvider := NewMockProvider("test-provider")
	mockProvider.capabilities.SupportedModels = []string{"model-1", "model-2"}

	factory.providers["test"] = mockProvider
	factory.healthChecks["test"] = true
	factory.lastHealthCheck["test"] = time.Now()

	request := &TaskRequest{
		TaskID:    "test-123",
		AgentRole: "developer",
		ModelName: "unsupported-model",
	}

	_, _, err := factory.GetProviderForTask(request)
	require.Error(t, err)
	assert.IsType(t, &ProviderError{}, err)

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

func TestProviderFactoryListProviders(t *testing.T) {
	factory := NewProviderFactory()

	// Add some mock providers
	factory.providers["provider1"] = NewMockProvider("provider1")
	factory.providers["provider2"] = NewMockProvider("provider2")
	factory.providers["provider3"] = NewMockProvider("provider3")

	providers := factory.ListProviders()

	assert.Len(t, providers, 3)
	assert.Contains(t, providers, "provider1")
	assert.Contains(t, providers, "provider2")
	assert.Contains(t, providers, "provider3")
}

func TestProviderFactoryListHealthyProviders(t *testing.T) {
	factory := NewProviderFactory()

	// Add providers with different health states
	factory.providers["healthy1"] = NewMockProvider("healthy1")
	factory.providers["healthy2"] = NewMockProvider("healthy2")
	factory.providers["unhealthy"] = NewMockProvider("unhealthy")

	factory.healthChecks["healthy1"] = true
	factory.healthChecks["healthy2"] = true
	factory.healthChecks["unhealthy"] = false

	factory.lastHealthCheck["healthy1"] = time.Now()
	factory.lastHealthCheck["healthy2"] = time.Now()
	factory.lastHealthCheck["unhealthy"] = time.Now()

	healthyProviders := factory.ListHealthyProviders()

	assert.Len(t, healthyProviders, 2)
	assert.Contains(t, healthyProviders, "healthy1")
	assert.Contains(t, healthyProviders, "healthy2")
	assert.NotContains(t, healthyProviders, "unhealthy")
}

func TestProviderFactoryGetProviderInfo(t *testing.T) {
	factory := NewProviderFactory()

	mock1 := NewMockProvider("mock1")
	mock2 := NewMockProvider("mock2")

	factory.providers["provider1"] = mock1
	factory.providers["provider2"] = mock2

	info := factory.GetProviderInfo()

	assert.Len(t, info, 2)
	assert.Contains(t, info, "provider1")
	assert.Contains(t, info, "provider2")

	// Verify that the name is overridden with the registered name
	assert.Equal(t, "provider1", info["provider1"].Name)
	assert.Equal(t, "provider2", info["provider2"].Name)
}

func TestProviderFactoryHealthCheck(t *testing.T) {
	factory := NewProviderFactory()

	// Add a healthy and an unhealthy provider
	healthyProvider := NewMockProvider("healthy")
	unhealthyProvider := NewMockProvider("unhealthy")
	unhealthyProvider.shouldFail = true

	factory.providers["healthy"] = healthyProvider
	factory.providers["unhealthy"] = unhealthyProvider

	ctx := context.Background()
	results := factory.HealthCheck(ctx)

	assert.Len(t, results, 2)
	assert.NoError(t, results["healthy"])
	assert.Error(t, results["unhealthy"])

	// Verify health states were updated
	assert.True(t, factory.healthChecks["healthy"])
	assert.False(t, factory.healthChecks["unhealthy"])
}

func TestProviderFactoryGetHealthStatus(t *testing.T) {
	factory := NewProviderFactory()

	mockProvider := NewMockProvider("test")
	factory.providers["test"] = mockProvider

	now := time.Now()
	factory.healthChecks["test"] = true
	factory.lastHealthCheck["test"] = now

	status := factory.GetHealthStatus()

	assert.Len(t, status, 1)
	assert.Contains(t, status, "test")

	testStatus := status["test"]
	assert.Equal(t, "test", testStatus.Name)
	assert.True(t, testStatus.Healthy)
	assert.Equal(t, now, testStatus.LastCheck)
}

func TestProviderFactoryIsProviderHealthy(t *testing.T) {
	factory := NewProviderFactory()

	// Test healthy provider
	factory.healthChecks["healthy"] = true
	factory.lastHealthCheck["healthy"] = time.Now()
	assert.True(t, factory.isProviderHealthy("healthy"))

	// Test unhealthy provider
	factory.healthChecks["unhealthy"] = false
	factory.lastHealthCheck["unhealthy"] = time.Now()
	assert.False(t, factory.isProviderHealthy("unhealthy"))

	// Test provider with old health check (should be considered unhealthy)
	factory.healthChecks["stale"] = true
	factory.lastHealthCheck["stale"] = time.Now().Add(-15 * time.Minute)
	assert.False(t, factory.isProviderHealthy("stale"))

	// Test non-existent provider
	assert.False(t, factory.isProviderHealthy("nonexistent"))
}

func TestProviderFactoryMergeRoleConfig(t *testing.T) {
	factory := NewProviderFactory()

	baseConfig := ProviderConfig{
		Type:         "test",
		DefaultModel: "base-model",
		Temperature:  0.7,
		MaxTokens:    4096,
		EnableTools:  false,
		EnableMCP:    false,
		MCPServers:   []string{"base-server"},
	}

	roleConfig := RoleConfig{
		Model:       "role-model",
		Temperature: 0.3,
		MaxTokens:   8192,
		EnableTools: true,
		EnableMCP:   true,
		MCPServers:  []string{"role-server"},
	}

	merged := factory.mergeRoleConfig(baseConfig, roleConfig)

	assert.Equal(t, "role-model", merged.DefaultModel)
	assert.Equal(t, float32(0.3), merged.Temperature)
	assert.Equal(t, 8192, merged.MaxTokens)
	assert.True(t, merged.EnableTools)
	assert.True(t, merged.EnableMCP)
	assert.Len(t, merged.MCPServers, 2) // Should be merged
	assert.Contains(t, merged.MCPServers, "base-server")
	assert.Contains(t, merged.MCPServers, "role-server")
}

func TestDefaultProviderFactory(t *testing.T) {
	factory := DefaultProviderFactory()

	// Should have at least the default ollama provider
	providers := factory.ListProviders()
	assert.Contains(t, providers, "ollama")

	// Should have role mappings configured
	assert.NotEmpty(t, factory.roleMapping.Roles)
	assert.Contains(t, factory.roleMapping.Roles, "developer")
	assert.Contains(t, factory.roleMapping.Roles, "reviewer")

	// Test getting provider for developer role
	_, config, err := factory.GetProviderForRole("developer")
	require.NoError(t, err)
	assert.Equal(t, "codellama:13b", config.DefaultModel)
	assert.Equal(t, float32(0.3), config.Temperature)
}

func TestProviderFactoryCreateProvider(t *testing.T) {
	factory := NewProviderFactory()

	tests := []struct {
		name      string
		config    ProviderConfig
		expectErr bool
	}{
		{
			name: "ollama provider",
			config: ProviderConfig{
				Type:         "ollama",
				Endpoint:     "http://localhost:11434",
				DefaultModel: "llama2",
			},
			expectErr: false,
		},
		{
			name: "openai provider",
			config: ProviderConfig{
				Type:         "openai",
				Endpoint:     "https://api.openai.com/v1",
				APIKey:       "test-key",
				DefaultModel: "gpt-4",
			},
			expectErr: false,
		},
		{
			name: "resetdata provider",
			config: ProviderConfig{
				Type:         "resetdata",
				Endpoint:     "https://api.resetdata.ai",
				APIKey:       "test-key",
				DefaultModel: "llama2",
			},
			expectErr: false,
		},
		{
			name: "unknown provider",
			config: ProviderConfig{
				Type: "unknown",
			},
			expectErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			provider, err := factory.CreateProvider(tt.config)

			if tt.expectErr {
				assert.Error(t, err)
				assert.Nil(t, provider)
			} else {
				assert.NoError(t, err)
				assert.NotNil(t, provider)
			}
		})
	}
}