package metrics

import (
	"encoding/json"
	"os"
	"strings"
	"testing"
	"time"
)

const fdinfoA = `pos:	0
flags:	02100002
drm-driver:	i915
drm-client-id:	544
drm-pdev:	0000:00:02.0
drm-total-system0:	52624 KiB
drm-resident-system0:	50140 KiB
drm-resident-stolen-system0:	32 KiB
drm-engine-render:	1000000000 ns
drm-engine-copy:	0 ns
drm-engine-video:	2000000000 ns
drm-engine-capacity-video:	2
drm-engine-video-enhance:	0 ns
`

func TestParseFdinfo(t *testing.T) {
	fi := parseFdinfo(fdinfoA)
	if fi.driver != "i915" || fi.pdev != "0000:00:02.0" || fi.client != "544" {
		t.Fatalf("identity: %+v", fi)
	}
	if fi.engines["video"] != 2000000000 || fi.capacity["video"] != 2 {
		t.Errorf("video engine: %+v", fi)
	}
	if fi.mem != (50140+32)<<10 {
		t.Errorf("resident = %d", fi.mem)
	}
}

func TestLspciName(t *testing.T) {
	for in, want := range map[string]string{
		"Intel Corporation DG2 [Arc A380] (rev 05)":                                              "Intel Arc A380",
		"Intel Corporation RocketLake-S GT1 [UHD Graphics 750] (rev 04)":                         "Intel UHD Graphics 750",
		"Intel Corporation Alder Lake-N [UHD Graphics]":                                          "Intel UHD Graphics",
		"Advanced Micro Devices, Inc. [AMD/ATI] Navi 23 [Radeon RX 6600/6600 XT/6600M] (rev c7)": "AMD Radeon RX 6600/6600 XT/6600M",
		"NVIDIA Corporation GA106 [GeForce RTX 3060 Lite Hash Rate] (rev a1)":                    "NVIDIA GeForce RTX 3060 Lite Hash Rate",
		"Moore Threads Technology Co.,Ltd MTT S80":                                               "Moore Threads Technology Co.,Ltd MTT S80",
	} {
		if got := lspciName(in); got != want {
			t.Errorf("%q → %q, want %q", in, got, want)
		}
	}
}

// Two scans a second apart: a client that ran its render engine for half of it and both
// video engines flat out reads 50% render, 100% video, and the device's engines follow.
func TestGPUClientsShare(t *testing.T) {
	c := NewCollector()
	d := &gpuDev{card: "/nonexistent/card9", dev: "/nonexistent", key: "0000:00:02.0", bus: "0000:00:02.0", driver: "i915", name: "Test GPU", integrated: true}
	c.gpu.devs = []*gpuDev{d}
	c.gpu.listedAt = time.Now().Add(time.Hour) // keep the fake list
	c.gpu.clients = map[string]clientPrev{}
	t0 := time.Now()
	c.gpu.last = []drmFD{{PID: 7, Comm: "ffmpeg", Info: fdinfoA}}
	c.gpu.scanAt = t0 // no walk: the fake list stands
	first := c.gpus(t0, 40)
	if len(first) != 1 || len(first[0].Clients) != 1 || first[0].Clients[0].Usage != 0 {
		t.Fatalf("first pass: %+v", first)
	}
	if first[0].Temp != 40 || first[0].TempSrc != "package" {
		t.Errorf("an integrated GPU wears the package temperature: %+v", first[0])
	}
	later := fdinfoA
	later = replace(later, "drm-engine-render:	1000000000 ns", "drm-engine-render:	1500000000 ns")
	later = replace(later, "drm-engine-video:	2000000000 ns", "drm-engine-video:	4000000000 ns")
	c.gpu.last = []drmFD{{PID: 7, Comm: "ffmpeg", Info: later}}
	c.gpu.scanAt = t0.Add(time.Second)
	got := c.gpus(t0.Add(time.Second), 40)
	cl := got[0].Clients[0]
	if cl.Engines["render"] != 50 || cl.Engines["video"] != 100 || cl.Usage != 100 {
		t.Errorf("client share: %+v", cl)
	}
	if got[0].Engines["video"] != 100 || got[0].Usage != 100 || got[0].UsageSrc != "clients" {
		t.Errorf("device from clients: %+v", got[0])
	}
	if got[0].MemUsed != cl.Mem {
		t.Errorf("resident memory should be the clients' sum: %d vs %d", got[0].MemUsed, cl.Mem)
	}
	// the Processes table joins the client to its row
	c.ring = []Sample{{T: 1, GPUs: got}}
	c.prevProc = nil
	table := c.Processes()
	if len(table.GPUs) != 1 {
		t.Errorf("table carries the GPUs: %+v", table.GPUs)
	}
}

func TestFlattenGPU(t *testing.T) {
	s := Sample{T: 5, GPUs: []GPU{{Name: "Intel Arc A380", Driver: "i915", Bus: "0000:03:00.0", Usage: 12, UsageSrc: "idle", Engines: map[string]float64{"video": 30}, PowerW: 9.5, PowerCapW: 55, MHz: 2450, MaxMHz: 2450, Clients: []GPUClient{{PID: 1}}}}}
	got := map[string]any{}
	for _, x := range flatten(s, nil) {
		got[x.ID] = x.Value
	}
	for id, want := range map[string]any{"gpu.intel_arc_a380.usage": 12.0, "gpu.intel_arc_a380.video": 30.0, "gpu.intel_arc_a380.power": 9.5, "gpu.intel_arc_a380.freq": 2450.0, "gpu.intel_arc_a380.clients": 1.0} {
		if got[id] != want {
			t.Errorf("%s = %v, want %v", id, got[id], want)
		}
	}
	if _, ok := got["gpu.intel_arc_a380.temp"]; ok {
		t.Error("no temperature sensor, no temperature")
	}
}

func replace(s, old, new string) string {
	for i := 0; i+len(old) <= len(s); i++ {
		if s[i:i+len(old)] == old {
			return s[:i] + new + s[i+len(old):]
		}
	}
	return s
}

// TestLiveGPU reads this machine's GPUs for real: HAMLAB_LIVE=1 go test -run TestLiveGPU -v ./internal/metrics
func TestLiveGPU(t *testing.T) {
	if os.Getenv("HAMLAB_LIVE") == "" {
		t.Skip("set HAMLAB_LIVE=1 to read the real hardware")
	}
	c := NewCollector()
	c.sample()
	time.Sleep(1100 * time.Millisecond)
	c.sample()
	s, _ := c.Latest()
	b, _ := json.MarshalIndent(s.GPUs, "", "  ")
	t.Logf("%s", b)
	for _, x := range flatten(s, func(id string) bool { return len(id) > 4 && id[:4] == "gpu." }) {
		t.Logf("%s = %v %s", x.ID, x.Value, x.Unit)
	}
}

// TestLiveARC: HAMLAB_LIVE=1 go test -run TestLiveARC -v ./internal/metrics
func TestLiveARC(t *testing.T) {
	if os.Getenv("HAMLAB_LIVE") == "" {
		t.Skip("set HAMLAB_LIVE=1 to read the real machine")
	}
	c := NewCollector()
	c.sample()
	time.Sleep(1100 * time.Millisecond)
	c.sample()
	s, _ := c.Latest()
	b, _ := json.MarshalIndent(s.ARC, "", "  ")
	t.Logf("%s", b)
	for _, x := range flatten(s, func(id string) bool { return strings.HasPrefix(id, "zfs.arc.") }) {
		t.Logf("%s = %v %s", x.ID, x.Value, x.Unit)
	}
}