package service

import (
	"testing"
	"time"

	"vidarchive/internal/models"
)

func TestComputeNextRun(t *testing.T) {
	svc := &SubscriptionService{}
	// A fixed reference time: 2026-06-21 12:30 local.
	from := time.Date(2026, 6, 21, 12, 30, 0, 0, time.Local)

	cases := []struct {
		kind    string
		custom  string
		wantErr bool
		check   func(t *testing.T, next time.Time)
	}{
		{kind: "hourly", check: func(t *testing.T, next time.Time) {
			if !next.After(from) || next.Minute() != 0 {
				t.Errorf("hourly: got %v", next)
			}
		}},
		{kind: "daily", check: func(t *testing.T, next time.Time) {
			if next.Hour() != 3 || next.Minute() != 0 || !next.After(from) {
				t.Errorf("daily: got %v", next)
			}
		}},
		{kind: "weekly", check: func(t *testing.T, next time.Time) {
			if next.Weekday() != time.Sunday || !next.After(from) {
				t.Errorf("weekly: got %v", next)
			}
		}},
		{kind: "monthly", check: func(t *testing.T, next time.Time) {
			if next.Day() != 1 || !next.After(from) {
				t.Errorf("monthly: got %v", next)
			}
		}},
		{kind: "cron", custom: "*/15 * * * *", check: func(t *testing.T, next time.Time) {
			if next.Minute() != 45 || !next.After(from) {
				t.Errorf("custom cron */15: got %v", next)
			}
		}},
		{kind: "cron", custom: "not a cron", wantErr: true},
		{kind: "cron", custom: "", wantErr: true},
		{kind: "bogus", wantErr: true},
	}

	for _, c := range cases {
		sub := &models.Subscription{ScheduleKind: c.kind, CronExpr: c.custom}
		next, err := svc.ComputeNextRun(sub, from)
		if c.wantErr {
			if err == nil {
				t.Errorf("kind=%q custom=%q: expected error, got %v", c.kind, c.custom, next)
			}
			continue
		}
		if err != nil {
			t.Errorf("kind=%q custom=%q: unexpected error: %v", c.kind, c.custom, err)
			continue
		}
		c.check(t, next)
	}
}