package resource

import (
	"testing"
)

func TestParseNvidiaSMI(t *testing.T) {
	output := `0, NVIDIA GeForce RTX 4090, 45, 30, 4096, 24576, 16.67, 150.5, 450.0
1, NVIDIA GeForce RTX 4090, 52, 75, 8192, 24576, 33.33, 320.0, 450.0`

	metrics := parseNvidiaSMI(output)
	if len(metrics) != 2 {
		t.Fatalf("expected 2 GPUs, got %d", len(metrics))
	}

	if metrics[0].Index != 0 {
		t.Errorf("expected index 0, got %d", metrics[0].Index)
	}
	if metrics[0].Name != "NVIDIA GeForce RTX 4090" {
		t.Errorf("unexpected name: %s", metrics[0].Name)
	}
	if metrics[0].TemperatureC != 45 {
		t.Errorf("expected temp 45, got %d", metrics[0].TemperatureC)
	}
	if metrics[0].UtilizationGPU != 30 {
		t.Errorf("expected util 30, got %d", metrics[0].UtilizationGPU)
	}
	if metrics[0].MemoryUsedMB != 4096 {
		t.Errorf("expected mem used 4096, got %d", metrics[0].MemoryUsedMB)
	}
	if metrics[0].MemoryTotalMB != 24576 {
		t.Errorf("expected mem total 24576, got %d", metrics[0].MemoryTotalMB)
	}
	if metrics[0].PowerDrawW != 150.5 {
		t.Errorf("expected power 150.5, got %f", metrics[0].PowerDrawW)
	}

	if metrics[1].Index != 1 {
		t.Errorf("expected index 1, got %d", metrics[1].Index)
	}
	if metrics[1].UtilizationGPU != 75 {
		t.Errorf("expected util 75, got %d", metrics[1].UtilizationGPU)
	}
}

func TestParseNvidiaSMIEmpty(t *testing.T) {
	metrics := parseNvidiaSMI("")
	if len(metrics) != 0 {
		t.Errorf("expected 0 metrics for empty input, got %d", len(metrics))
	}
}

func TestParseNvidiaSMIInvalidLines(t *testing.T) {
	output := `invalid line
0, GPU0, 40, 50, 1024, 8192, 12.5, 100.0, 300.0
, , , , , , , , `

	metrics := parseNvidiaSMI(output)
	// Both lines with 9 fields parse; the empty-name one has Name=""
	validCount := 0
	for _, m := range metrics {
		if m.Name != "" {
			validCount++
		}
	}
	if validCount != 1 {
		t.Errorf("expected 1 valid metric with name, got %d", validCount)
	}
}

func TestGPUCollectorTotals(t *testing.T) {
	c := &GPUCollector{
		metrics: []GPUMetrics{
			{MemoryUsedMB: 4096, MemoryTotalMB: 24576, UtilizationGPU: 30},
			{MemoryUsedMB: 8192, MemoryTotalMB: 24576, UtilizationGPU: 75},
		},
	}

	if c.TotalMemoryUsedMB() != 12288 {
		t.Errorf("expected 12288, got %d", c.TotalMemoryUsedMB())
	}
	if c.TotalMemoryTotalMB() != 49152 {
		t.Errorf("expected 49152, got %d", c.TotalMemoryTotalMB())
	}

	avg := c.AverageUtilization()
	if avg != 52.5 {
		t.Errorf("expected 52.5, got %f", avg)
	}

	ratio := c.MemoryUtilizationRatio()
	expectedRatio := 12288.0 / 49152.0
	if ratio != expectedRatio {
		t.Errorf("expected %f, got %f", expectedRatio, ratio)
	}
}

func TestGPUCollectorEmpty(t *testing.T) {
	c := &GPUCollector{}
	if c.TotalMemoryUsedMB() != 0 {
		t.Error("expected 0 for empty collector")
	}
	if c.AverageUtilization() != 0 {
		t.Error("expected 0 for empty collector")
	}
	if c.MemoryUtilizationRatio() != 0 {
		t.Error("expected 0 for empty collector")
	}
}

func TestParseIntSafe(t *testing.T) {
	if parseIntSafe("42") != 42 {
		t.Error("expected 42")
	}
	if parseIntSafe("invalid") != 0 {
		t.Error("expected 0 for invalid")
	}
	if parseIntSafe("  100  ") != 100 {
		t.Error("expected 100 with whitespace")
	}
}

func TestParseFloatSafe(t *testing.T) {
	if parseFloatSafe("3.14") != 3.14 {
		t.Error("expected 3.14")
	}
	if parseFloatSafe("invalid") != 0 {
		t.Error("expected 0 for invalid")
	}
}