// ABOUTME: Tests for the summary writer that emits run summaries via slog.
// ABOUTME: Validates JSON output, text output, and nil summary handling.
package summary

import (
	"bytes"
	"strings"
	"testing"
	"time"
)

func TestSummaryWriter_JSON(t *testing.T) {
	var buf bytes.Buffer
	w := NewSummaryWriter(&buf, "json")

	s := &RunSummary{
		StartTime:       time.Date(2025, 1, 1, 0, 0, 0, 0, time.UTC),
		EndTime:         time.Date(2025, 1, 1, 0, 1, 0, 0, time.UTC),
		DurationSeconds: 60,
		SampleCount:     12,
		CPUTotal:        StatSummary{Peak: 95.5, Avg: 42.0, P95: 88.0},
		MemUsedBytes:    StatSummary{Peak: 8000000, Avg: 4000000, P95: 7500000},
		MemUsedPercent:  StatSummary{Peak: 80.0, Avg: 40.0, P95: 75.0},
		TopCPUProcesses: []ProcessPeak{
			{PID: 1, Name: "busy", PeakCPU: 95.5, PeakMem: 1000},
		},
		TopMemProcesses: []ProcessPeak{
			{PID: 2, Name: "hungry", PeakCPU: 10.0, PeakMem: 8000000},
		},
	}

	w.Write(s)

	output := buf.String()
	if !strings.Contains(output, "run_summary") {
		t.Errorf("output should contain 'run_summary', got: %s", output)
	}
	if !strings.Contains(output, "duration_seconds") {
		t.Errorf("output should contain 'duration_seconds', got: %s", output)
	}
	if !strings.Contains(output, "sample_count") {
		t.Errorf("output should contain 'sample_count', got: %s", output)
	}
	if !strings.Contains(output, "cpu_total_percent") {
		t.Errorf("output should contain 'cpu_total_percent', got: %s", output)
	}
	if !strings.Contains(output, "mem_used_bytes") {
		t.Errorf("output should contain 'mem_used_bytes', got: %s", output)
	}
	if !strings.Contains(output, "top_cpu_processes") {
		t.Errorf("output should contain 'top_cpu_processes', got: %s", output)
	}
	if !strings.Contains(output, "top_mem_processes") {
		t.Errorf("output should contain 'top_mem_processes', got: %s", output)
	}
}

func TestSummaryWriter_Text(t *testing.T) {
	var buf bytes.Buffer
	w := NewSummaryWriter(&buf, "text")

	s := &RunSummary{
		StartTime:       time.Date(2025, 1, 1, 0, 0, 0, 0, time.UTC),
		EndTime:         time.Date(2025, 1, 1, 0, 1, 0, 0, time.UTC),
		DurationSeconds: 60,
		SampleCount:     12,
		CPUTotal:        StatSummary{Peak: 95.5, Avg: 42.0, P95: 88.0},
		MemUsedBytes:    StatSummary{Peak: 8000000, Avg: 4000000, P95: 7500000},
		MemUsedPercent:  StatSummary{Peak: 80.0, Avg: 40.0, P95: 75.0},
	}

	w.Write(s)

	output := buf.String()
	if !strings.Contains(output, "run_summary") {
		t.Errorf("output should contain 'run_summary', got: %s", output)
	}
	if !strings.Contains(output, "duration_seconds") {
		t.Errorf("output should contain 'duration_seconds', got: %s", output)
	}
}

func TestSummaryWriter_NilSummary(t *testing.T) {
	var buf bytes.Buffer
	w := NewSummaryWriter(&buf, "json")

	// Should not panic and should not write anything
	w.Write(nil)

	if buf.Len() != 0 {
		t.Errorf("expected no output for nil summary, got: %s", buf.String())
	}
}