package platform

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

const ncclValidOutput = `# size count type redop root time algbw busbw #wrong time algbw busbw #wrong
536870912 134217728 float sum -1 19547 27.47 48.07 0 19512 27.52 48.15 0
# Out of bounds values : 0 OK
# Avg bus bandwidth    : 48.1908
`

func TestValidateNCCLAllReduceOutputHealthyNVLinkPair(t *testing.T) {
	runDir := t.TempDir()
	writeNCCLValidationArtifact(t, runDir, "01-nvidia-smi-topo-m.log", "\tGPU0\tGPU1\nGPU0\tX\tNV2\nGPU1\tNV2\tX\n")
	writeNCCLValidationArtifact(t, runDir, "01-nvidia-smi-nvlink-s.log", `GPU 0: H100
Link 0: 26.562 GB/s
Link 1: 26.562 GB/s
GPU 1: H100
Link 0: 26.562 GB/s
Link 1: 26.562 GB/s
`)
	status, detail := validateNCCLAllReduceOutput(runDir, []byte(ncclValidOutput), []int{0, 1})
	if status != "OK" {
		t.Fatalf("status=%q detail=%q want OK", status, detail)
	}
}

func TestValidateNCCLAllReduceOutputFailsInactiveNVLinkEndpoint(t *testing.T) {
	runDir := t.TempDir()
	writeNCCLValidationArtifact(t, runDir, "01-nvidia-smi-topo-m.log", "\tGPU0\tGPU1\nGPU0\tX\tNV2\nGPU1\tNV2\tX\n")
	writeNCCLValidationArtifact(t, runDir, "01-nvidia-smi-nvlink-s.log", `GPU 0: H100
Link 0: 26.562 GB/s
Link 1: 26.562 GB/s
GPU 1: H100
NVML: Unable to retrieve NVLink information as all links are inActive
`)
	status, detail := validateNCCLAllReduceOutput(runDir, []byte(ncclValidOutput), []int{0, 1})
	if status != "FAILED" || !strings.Contains(detail, "GPU1 0/2") {
		t.Fatalf("status=%q detail=%q want FAILED with GPU1 0/2", status, detail)
	}
}

func TestValidateNCCLAllReduceOutputRejectsWrongValues(t *testing.T) {
	bad := strings.Replace(ncclValidOutput, "48.07 0", "48.07 2", 1)
	status, detail := validateNCCLAllReduceOutput(t.TempDir(), []byte(bad), []int{0})
	if status != "FAILED" || !strings.Contains(detail, "2 wrong") {
		t.Fatalf("status=%q detail=%q want wrong-value failure", status, detail)
	}
}

func TestValidateNCCLAllReduceOutputPCIeOnlyDoesNotRequireNVLink(t *testing.T) {
	runDir := t.TempDir()
	writeNCCLValidationArtifact(t, runDir, "01-nvidia-smi-topo-m.log", "\tGPU0\tGPU1\nGPU0\tX\tPIX\nGPU1\tPIX\tX\n")
	status, detail := validateNCCLAllReduceOutput(runDir, []byte(ncclValidOutput), []int{0, 1})
	if status != "OK" || !strings.Contains(detail, "no NVLink-bonded pair") {
		t.Fatalf("status=%q detail=%q want PCIe-only OK", status, detail)
	}
}

func TestValidateNCCLAllReduceOutputUnknownFormatIsUnsupported(t *testing.T) {
	status, _ := validateNCCLAllReduceOutput(t.TempDir(), []byte("all done\n"), []int{0})
	if status != "UNSUPPORTED" {
		t.Fatalf("status=%q want UNSUPPORTED", status)
	}
}

func TestRunAcceptancePackAppliesOutputValidator(t *testing.T) {
	runDir, err := runAcceptancePackCtx(context.Background(), t.TempDir(), "validator-test", []satJob{{
		name: "01-result.log",
		cmd:  []string{"sh", "-c", "printf command-ok"},
		validate: func(string, []byte) (string, string) {
			return "FAILED", "documented output check failed"
		},
	}}, nil)
	if err != nil {
		t.Fatal(err)
	}
	summary, err := os.ReadFile(filepath.Join(runDir, "summary.txt"))
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(string(summary), "overall_status=FAILED") ||
		!strings.Contains(string(summary), "1-result_detail=documented output check failed") {
		t.Fatalf("summary did not retain validator failure:\n%s", summary)
	}
	logData, err := os.ReadFile(filepath.Join(runDir, "01-result.log"))
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(string(logData), "[bee-validator] FAILED: documented output check failed") {
		t.Fatalf("job log did not retain validator result:\n%s", logData)
	}
}

func TestNCCLJobHealthAndDebugConfiguration(t *testing.T) {
	jobs := ncclSATJobs([]int{0, 2})
	var job satJob
	for _, candidate := range jobs {
		if candidate.name == "02-all-reduce-perf.log" {
			job = candidate
			break
		}
	}
	if job.name == "" || job.validate == nil {
		t.Fatal("all_reduce_perf job or its output validator is missing")
	}
	if !nvidiaJobNeedsHealthCheck(job) {
		t.Fatal("all_reduce_perf job must run NVIDIA health checks")
	}
	if !isNvidiaAcceptancePack("nccl-tests") {
		t.Fatal("nccl-tests must produce NVIDIA per-GPU status files")
	}
	env := strings.Join(job.env, "\n")
	for _, expected := range []string{
		"CUDA_DEVICE_ORDER=PCI_BUS_ID",
		"CUDA_VISIBLE_DEVICES=0,2",
		"NCCL_DEBUG=INFO",
		"NCCL_DEBUG_SUBSYS=INIT,GRAPH",
	} {
		if !strings.Contains(env, expected) {
			t.Fatalf("job env=%q missing %q", env, expected)
		}
	}
}

func writeNCCLValidationArtifact(t *testing.T, dir, name, body string) {
	t.Helper()
	if err := os.WriteFile(filepath.Join(dir, name), []byte(body), 0644); err != nil {
		t.Fatal(err)
	}
}