package worker_test

import (
	"os"
	"path/filepath"
	"testing"
	"time"

	"github.com/jfraeys/fetch_ml/internal/manifest"
	"github.com/jfraeys/fetch_ml/internal/worker"
)

// TestGPUDetectorEnvOverrides validates both FETCH_ML_GPU_TYPE and FETCH_ML_GPU_COUNT work
func TestGPUDetectorEnvOverrides(t *testing.T) {
	tests := []struct {
		name           string
		gpuType        string
		gpuCount       string
		wantType       worker.GPUType
		wantCount      int
		wantMethod     worker.DetectionSource
		wantConfigured string
	}{
		{
			name:           "env type only - nvidia",
			gpuType:        "nvidia",
			wantType:       worker.GPUTypeNVIDIA,
			wantMethod:     worker.DetectionSourceEnvType,
			wantConfigured: "nvidia",
		},
		{
			name:           "env type only - apple",
			gpuType:        "apple",
			wantType:       worker.GPUTypeApple,
			wantMethod:     worker.DetectionSourceEnvType,
			wantConfigured: "apple",
		},
		{
			name:           "env type only - none",
			gpuType:        "none",
			wantType:       worker.GPUTypeNone,
			wantMethod:     worker.DetectionSourceEnvType,
			wantConfigured: "none",
		},
		{
			name:           "both env vars set",
			gpuType:        "nvidia",
			gpuCount:       "4",
			wantType:       worker.GPUTypeNVIDIA,
			wantMethod:     worker.DetectionSourceEnvBoth,
			wantConfigured: "nvidia",
		},
		{
			name:           "env type amd - shows amd configured vendor",
			gpuType:        "amd",
			wantType:       worker.GPUTypeAMD,
			wantMethod:     worker.DetectionSourceEnvType,
			wantConfigured: "amd",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Set env vars
			if tt.gpuType != "" {
				os.Setenv("FETCH_ML_GPU_TYPE", tt.gpuType)
				defer os.Unsetenv("FETCH_ML_GPU_TYPE")
			}
			if tt.gpuCount != "" {
				os.Setenv("FETCH_ML_GPU_COUNT", tt.gpuCount)
				defer os.Unsetenv("FETCH_ML_GPU_COUNT")
			}

			factory := &worker.GPUDetectorFactory{}
			result := factory.CreateDetectorWithInfo(nil)

			if result.Info.GPUType != tt.wantType {
				t.Errorf("GPUType = %v, want %v", result.Info.GPUType, tt.wantType)
			}
			if result.Info.DetectionMethod != tt.wantMethod {
				t.Errorf("DetectionMethod = %v, want %v", result.Info.DetectionMethod, tt.wantMethod)
			}
			if result.Info.ConfiguredVendor != tt.wantConfigured {
				t.Errorf("ConfiguredVendor = %v, want %v", result.Info.ConfiguredVendor, tt.wantConfigured)
			}
		})
	}
}

// TestAMDAliasManifestRecord validates AMD config shows proper aliasing and records to manifest
func TestAMDAliasManifestRecord(t *testing.T) {
	cfg := &worker.Config{
		GPUVendor: "amd",
	}

	factory := &worker.GPUDetectorFactory{}
	result := factory.CreateDetectorWithInfo(cfg)

	// AMD uses NVIDIA detector implementation
	if result.Info.ConfiguredVendor != "amd" {
		t.Errorf("ConfiguredVendor = %v, want 'amd'", result.Info.ConfiguredVendor)
	}
	if result.Info.GPUType != worker.GPUTypeNVIDIA {
		t.Errorf("GPUType = %v, want %v (NVIDIA implementation for AMD alias)", result.Info.GPUType, worker.GPUTypeNVIDIA)
	}

	// R.3: Record GPU detection info to manifest
	m := manifest.NewRunManifest("run-test-amd", "task-amd", "job-amd", time.Now())
	m.Environment = &manifest.ExecutionEnvironment{
		GPUDetectionMethod: string(result.Info.DetectionMethod),
		GPUVendor:          result.Info.ConfiguredVendor,
		GPUCount:           1, // AMD detection returns count from NVIDIA implementation
	}

	// Write and reload manifest to verify persistence
	dir := t.TempDir()
	if err := m.WriteToDir(dir); err != nil {
		t.Fatalf("WriteToDir failed: %v", err)
	}

	loaded, err := manifest.LoadFromDir(dir)
	if err != nil {
		t.Fatalf("LoadFromDir failed: %v", err)
	}

	// Verify GPU info was persisted
	if loaded.Environment == nil {
		t.Fatal("expected Environment to be written to manifest")
	}
	if loaded.Environment.GPUVendor != result.Info.ConfiguredVendor {
		t.Errorf("GPUVendor mismatch: got %q, want %q", loaded.Environment.GPUVendor, result.Info.ConfiguredVendor)
	}
	if loaded.Environment.GPUDetectionMethod != string(result.Info.DetectionMethod) {
		t.Errorf("GPUDetectionMethod mismatch: got %q, want %q", loaded.Environment.GPUDetectionMethod, result.Info.DetectionMethod)
	}

	// Verify manifest file includes nonce for security
	manifestFile := filepath.Join(dir, "run_manifest.json")
	if _, err := os.Stat(manifestFile); os.IsNotExist(err) {
		t.Error("expected run_manifest.json to exist")
	}
}

// TestGPUDetectorEnvCountOverride validates FETCH_ML_GPU_COUNT with auto-detect
func TestGPUDetectorEnvCountOverride(t *testing.T) {
	os.Setenv("FETCH_ML_GPU_COUNT", "8")
	defer os.Unsetenv("FETCH_ML_GPU_COUNT")

	cfg := &worker.Config{
		GPUVendor: "nvidia",
	}

	factory := &worker.GPUDetectorFactory{}
	result := factory.CreateDetectorWithInfo(cfg)

	if result.Info.DetectionMethod != worker.DetectionSourceEnvCount {
		t.Errorf("DetectionMethod = %v, want %v", result.Info.DetectionMethod, worker.DetectionSourceEnvCount)
	}
	if result.Info.EnvOverrideCount != 8 {
		t.Errorf("EnvOverrideCount = %v, want 8", result.Info.EnvOverrideCount)
	}
}

// TestGPUDetectorDetectionSources validates all detection source types
func TestGPUDetectorDetectionSources(t *testing.T) {
	tests := []struct {
		name       string
		envType    string
		envCount   string
		config     *worker.Config
		wantSource worker.DetectionSource
	}{
		{
			name:       "env type takes precedence over config",
			envType:    "apple",
			config:     &worker.Config{GPUVendor: "nvidia"},
			wantSource: worker.DetectionSourceEnvType,
		},
		{
			name:       "env count triggers env_count source",
			envCount:   "2",
			config:     &worker.Config{GPUVendor: "nvidia"},
			wantSource: worker.DetectionSourceEnvCount,
		},
		{
			name:       "config source when no env",
			config:     &worker.Config{GPUVendor: "nvidia"},
			wantSource: worker.DetectionSourceConfig,
		},
		{
			name:       "auto source for GPUDevices",
			config:     &worker.Config{GPUDevices: []string{"/dev/nvidia0"}},
			wantSource: worker.DetectionSourceAuto,
		},
		{
			name:       "auto source for AppleGPU",
			config:     &worker.Config{AppleGPU: worker.AppleGPUConfig{Enabled: true}},
			wantSource: worker.DetectionSourceAuto,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if tt.envType != "" {
				os.Setenv("FETCH_ML_GPU_TYPE", tt.envType)
				defer os.Unsetenv("FETCH_ML_GPU_TYPE")
			}
			if tt.envCount != "" {
				os.Setenv("FETCH_ML_GPU_COUNT", tt.envCount)
				defer os.Unsetenv("FETCH_ML_GPU_COUNT")
			}

			factory := &worker.GPUDetectorFactory{}
			result := factory.CreateDetectorWithInfo(tt.config)

			if result.Info.DetectionMethod != tt.wantSource {
				t.Errorf("DetectionMethod = %v, want %v", result.Info.DetectionMethod, tt.wantSource)
			}
		})
	}
}

// TestGPUDetectorInfoFields validates all GPUDetectionInfo fields are populated
func TestGPUDetectorInfoFields(t *testing.T) {
	os.Setenv("FETCH_ML_GPU_TYPE", "nvidia")
	os.Setenv("FETCH_ML_GPU_COUNT", "4")
	defer os.Unsetenv("FETCH_ML_GPU_TYPE")
	defer os.Unsetenv("FETCH_ML_GPU_COUNT")

	factory := &worker.GPUDetectorFactory{}
	result := factory.CreateDetectorWithInfo(nil)

	// Validate all expected fields
	if result.Info.GPUType == "" {
		t.Error("GPUType field is empty")
	}
	if result.Info.ConfiguredVendor == "" {
		t.Error("ConfiguredVendor field is empty")
	}
	if result.Info.DetectionMethod == "" {
		t.Error("DetectionMethod field is empty")
	}
	if result.Info.EnvOverrideType != "nvidia" {
		t.Errorf("EnvOverrideType = %v, want 'nvidia'", result.Info.EnvOverrideType)
	}
	if result.Info.EnvOverrideCount != 4 {
		t.Errorf("EnvOverrideCount = %v, want 4", result.Info.EnvOverrideCount)
	}
}