package storage

import (
	"testing"
	"time"
)

func TestSnapTimeReadsZfSnapNames(t *testing.T) {
	// the real thing off grid
	taken, exp, ok := SnapTime("tank@2026-09-24_02.30.01--6w")
	if !ok {
		t.Fatal("zfSnap's own name must parse")
	}
	if taken.Format("2006-01-02 15:04:05") != "2026-09-24 02:30:01" {
		t.Fatalf("taken = %v", taken)
	}
	if got := exp.Sub(taken); got != 6*7*24*time.Hour {
		t.Fatalf("ttl = %v, want 6w", got)
	}
	// a labelled one from a policy with a prefix
	if _, e, ok := SnapTime("tank/apps@nightly-2026-09-24_02.30.01--30d"); !ok || e.IsZero() {
		t.Fatal("a prefixed name must parse and expire")
	}
	// no TTL: never expires
	if _, e, ok := SnapTime("tank@2026-09-24_02.30.01"); !ok || !e.IsZero() {
		t.Fatal("a name without a TTL must parse and never expire")
	}
	// things that are not ours
	for _, n := range []string{"tank@before-upgrade", "tank@manual", "tank", "tank@2026-13-45_99.99.99--6w"} {
		if _, _, ok := SnapTime(n); ok {
			t.Errorf("%q must not parse as a scheduled snapshot", n)
		}
	}
}

func TestScheduleIsDueAndNext(t *testing.T) {
	now := time.Date(2026, 9, 24, 9, 15, 0, 0, time.Local)
	daily := &Policy{Every: "daily", At: "02:30", Enabled: true}
	if d := daily.lastDue(now); d.Hour() != 2 || d.Day() != 24 {
		t.Fatalf("daily lastDue = %v", d)
	}
	if !daily.Due(now) {
		t.Fatal("never run: must be due")
	}
	daily.LastRun = now.Add(-time.Hour) // ran at 08:15 today, after 02:30
	if daily.Due(now) {
		t.Fatal("already ran since the window: not due")
	}
	if n := daily.NextRun(now); n.Day() != 25 || n.Hour() != 2 {
		t.Fatalf("daily NextRun = %v", n)
	}
	// a machine that was off through its window runs once when it comes back, not never
	daily.LastRun = now.AddDate(0, 0, -2)
	if !daily.Due(now) {
		t.Fatal("a missed window must still be due")
	}
	// disabled never runs
	daily.Enabled = false
	if daily.Due(now) {
		t.Fatal("disabled must never be due")
	}
	weekly := &Policy{Every: "weekly", At: "04:00", Weekday: int(time.Sunday), Enabled: true}
	if d := weekly.lastDue(now); d.Weekday() != time.Sunday || d.After(now) {
		t.Fatalf("weekly lastDue = %v (%v)", d, d.Weekday())
	}
	hourly := &Policy{Every: "hourly", At: "00:30", Enabled: true}
	if d := hourly.lastDue(now); d.Minute() != 30 || d.Hour() != 8 {
		t.Fatalf("hourly lastDue at 09:15 with minute 30 = %v, want 08:30", d)
	}
}

func TestValidateRefusesNonsense(t *testing.T) {
	ok := Policy{Dataset: "tank/apps", Every: "daily", At: "02:30", KeepFor: "6w"}
	if err := ok.Validate(); err != nil {
		t.Fatalf("a sane policy: %v", err)
	}
	bad := []Policy{
		{Dataset: "", Every: "daily", At: "02:30", KeepFor: "6w"},
		{Dataset: "tank", Every: "yearly", At: "02:30", KeepFor: "6w"},
		{Dataset: "tank", Every: "daily", At: "25:00", KeepFor: "6w"},
		{Dataset: "tank", Every: "daily", At: "02:30"},                          // no retention
		{Dataset: "tank", Every: "daily", At: "02:30", KeepFor: "6 weeks"},      // unparseable
		{Dataset: "tank", Every: "monthly", At: "02:30", Day: 31, KeepFor: "6w"}, // not every month has one
		{Dataset: "tank", Every: "daily", At: "02:30", KeepFor: "6w", Prefix: "a--b"},
	}
	for i, p := range bad {
		if err := p.Validate(); err == nil {
			t.Errorf("bad policy %d was accepted: %+v", i, p)
		}
	}
}

func TestParseAge(t *testing.T) {
	for s, want := range map[string]time.Duration{
		"6w": 6 * 7 * 24 * time.Hour, "30d": 30 * 24 * time.Hour,
		"12h": 12 * time.Hour, "90m": 90 * time.Minute,
	} {
		if got, err := ParseAge(s); err != nil || got != want {
			t.Errorf("ParseAge(%q) = %v, %v; want %v", s, got, err, want)
		}
	}
	for _, s := range []string{"", "6", "w", "-1d", "0w", "6y", "six weeks"} {
		if _, err := ParseAge(s); err == nil {
			t.Errorf("ParseAge(%q) should fail", s)
		}
	}
}