package platform

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
)

func TestPCIeLinkSummaryAcceptsIdleGen1WhenLinkReachesMaximumUnderLoad(t *testing.T) {
	path := filepath.Join(t.TempDir(), "summary.txt")
	if err := os.WriteFile(path, []byte("overall_status=OK\n"), 0644); err != nil {
		t.Fatal(err)
	}
	findings := []nvidiaPCIeBandwidthFinding{{
		Index: 0, BDF: "0000:05:00.0", BeforeSpeed: "Gen1", AfterSpeed: "Gen5",
		MaxSpeed: "Gen5", Width: 16, MaxWidth: 16, Supported: true, Sampled: true,
	}}

	if err := appendNvidiaPCIeLinkSummary(path, findings); err != nil {
		t.Fatal(err)
	}
	raw, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	got := string(raw)
	if !strings.Contains(got, "overall_status=OK\n") || !strings.Contains(got, "pcie_link_under_load_status=OK\n") {
		t.Fatalf("summary did not accept a link that rose from idle Gen1 to maximum under load:\n%s", got)
	}
}

func TestPCIeLinkSummaryFailsLinkStillBelowMaximumAfterLoad(t *testing.T) {
	path := filepath.Join(t.TempDir(), "summary.txt")
	if err := os.WriteFile(path, []byte("overall_status=UNSUPPORTED\n"), 0644); err != nil {
		t.Fatal(err)
	}
	findings := []nvidiaPCIeBandwidthFinding{{
		Index: 0, BDF: "0000:05:00.0", BeforeSpeed: "Gen1", AfterSpeed: "Gen1",
		MaxSpeed: "Gen5", Width: 16, MaxWidth: 16, Supported: true, Sampled: true, Degraded: true,
	}}

	if err := appendNvidiaPCIeLinkSummary(path, findings); err != nil {
		t.Fatal(err)
	}
	raw, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	got := string(raw)
	if !strings.Contains(got, "overall_status=FAILED\n") || !strings.Contains(got, "pcie_link_under_load_status=FAILED\n") {
		t.Fatalf("summary did not fail a link that stayed degraded under load:\n%s", got)
	}
}

func TestPCIeLinkSummaryIsUnsupportedWhenLoadNeverRan(t *testing.T) {
	path := filepath.Join(t.TempDir(), "summary.txt")
	if err := os.WriteFile(path, []byte("overall_status=FAILED\n"), 0644); err != nil {
		t.Fatal(err)
	}
	findings := []nvidiaPCIeBandwidthFinding{{
		Index: 0, BDF: "0000:05:00.0", BeforeSpeed: "Gen1", MaxSpeed: "Gen5",
		MaxWidth: 16, Supported: true,
	}}

	if err := appendNvidiaPCIeLinkSummary(path, findings); err != nil {
		t.Fatal(err)
	}
	raw, err := os.ReadFile(path)
	if err != nil {
		t.Fatal(err)
	}
	got := string(raw)
	if !strings.Contains(got, "pcie_link_under_load_status=UNSUPPORTED\n") {
		t.Fatalf("summary claimed a link verdict although the load callback never ran:\n%s", got)
	}
}