package main

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

func TestOnlinePoolsWithoutErrorsAreHealthyAndAnOldScrubIsOnlyAWarning(t *testing.T) {
	h := withZFS(t).machine().Health(context.Background())
	if !h.Healthy || len(h.Found) != 0 {
		t.Fatalf("health: %+v", h)
	}
	if len(h.Warnings) != 1 || !strings.Contains(h.Warnings[0], "Pool rpool was last scrubbed 89 days ago, more than 35") {
		t.Errorf("rpool's July scrub is a warning; tank's September one is not: %v", h.Warnings)
	}
	if !strings.Contains(h.Why, "tank ONLINE, 60 % full") {
		t.Errorf("why: %s", h.Why)
	}
}

func TestADegradedFullPoolIsUnhealthyWithEveryReason(t *testing.T) {
	f := newFake(t)
	f.on(line("zpool", PoolsArgv()), fixture(t, "zpool-list-full.txt"))
	f.on(line("zpool", StatusArgv()), fixture(t, "zpool-status-degraded.txt"))
	h := f.machine().Health(context.Background())
	if h.Healthy {
		t.Fatalf("healthy: %+v", h)
	}
	for _, want := range []string{
		"Pool tank is DEGRADED: One or more devices is currently being resilvered",
		"Action: Wait for the resilver to complete",
		"Pool tank is 91 % full, past 90 %",
		"device ata-WDC_WD120EFBX-68B0EN0_D7JA0002 in pool tank has errors: read 12, write 107, checksum 3",
		"device ata-WDC_WD120EFBX-68B0EN0_D7JA0002 in pool tank is FAULTED",
		"Pool tank: 2 data errors",
	} {
		if !strings.Contains(h.Why, want) {
			t.Errorf("why lacks %q: %s", want, h.Why)
		}
	}
	if strings.Contains(h.Why, "D7JA0009 in pool tank is") {
		t.Errorf("a spare in use is not a finding: %s", h.Why)
	}
}

func TestCapacityPastEightyIsAWarningAndPastNinetyUnhealthy(t *testing.T) {
	st, _ := ParseStatus(fixture(t, "zpool-status-scrubbing.txt"))
	now := newFake(t).now
	p := Pool{Name: "tank", Capacity: 85, Health: "ONLINE"}
	if h := Judge([]Pool{p}, st, now); !h.Healthy || len(h.Warnings) != 1 || !strings.Contains(h.Warnings[0], "85 % full, past 80 %") {
		t.Errorf("85 %%: %+v", h)
	}
	p.Capacity = 80
	if h := Judge([]Pool{p}, st, now); !h.Healthy || len(h.Warnings) != 0 {
		t.Errorf("80 %% is not past 80: %+v", h)
	}
	p.Capacity = 92
	if h := Judge([]Pool{p}, st, now); h.Healthy {
		t.Errorf("92 %%: %+v", h)
	}
}

func TestFaultedAndNoPoolAreUnhealthy(t *testing.T) {
	now := newFake(t).now
	if h := Judge(nil, nil, now); h.Healthy || !strings.Contains(h.Why, "no pool is imported") {
		t.Errorf("no pool: %+v", h)
	}
	st := []PoolStatus{{Name: "tank", State: "FAULTED", Status: "One or more devices could not be opened.", Errors: "No known data errors",
		Root: &Device{Name: "tank", Kind: "pool", State: "FAULTED"}}}
	if h := Judge([]Pool{{Name: "tank", Health: "FAULTED"}}, st, now); h.Healthy || !strings.Contains(h.Why, "Pool tank is FAULTED: One or more devices could not be opened") {
		t.Errorf("faulted: %+v", h)
	}
}

func TestTheWatchSaysOnlyChanges(t *testing.T) {
	f := withZFS(t)
	var out bytes.Buffer
	w := &Watch{M: f.machine(), Out: &out}
	w.Look(context.Background())
	w.Look(context.Background())
	if n := strings.Count(out.String(), "\n"); n != 1 || !strings.Contains(out.String(), "healthy: Every pool is online") {
		t.Errorf("one line for one state: %q", out.String())
	}
	f.on(line("zpool", StatusArgv()), fixture(t, "zpool-status-degraded.txt"))
	w.Look(context.Background())
	if !strings.Contains(out.String(), "UNHEALTHY: ") {
		t.Errorf("the change is said: %q", out.String())
	}
}

func TestTheFollowerWritesEachNotableEventFromItsStartOnce(t *testing.T) {
	var out bytes.Buffer
	since := time.Date(2026, 10, 8, 21, 0, 0, 0, time.Local)
	if err := Follow(strings.NewReader(fixture(t, "zpool-events.txt")), &out, since); err != nil {
		t.Fatal(err)
	}
	got := strings.Split(strings.TrimSpace(out.String()), "\n")
	if len(got) != 3 || !strings.Contains(got[0], "ereport.fs.zfs.io") || !strings.Contains(got[1], "vdev_state=FAULTED") ||
		!strings.Contains(got[2], "resilver_start") {
		t.Errorf("lines: %q", got)
	}
	out.Reset()
	Follow(strings.NewReader(fixture(t, "zpool-events.txt")), &out, time.Date(2026, 10, 8, 21, 2, 10, 0, time.Local))
	if got := strings.TrimSpace(out.String()); strings.Count(got, "\n") != 0 || !strings.Contains(got, "resilver_start") {
		t.Errorf("only what came after since: %q", got)
	}
	if strings.Join(FollowArgv(), " ") != "events -f -v" {
		t.Errorf("argv: %v", FollowArgv())
	}
}