package scheduler

import (
	"testing"
	"time"

	"github.com/vasyansk/imap-copier/internal/store"
)

func TestNextRun(t *testing.T) {
	anchor := time.Date(2026, 7, 3, 10, 0, 0, 0, time.UTC)
	fin := time.Date(2026, 7, 3, 11, 0, 0, 0, time.UTC)

	// No finished run yet → anchor + interval.
	if got := NextRun(time.Hour, anchor, nil); !got.Equal(anchor.Add(time.Hour)) {
		t.Fatalf("first run: got %v", got)
	}
	// Finished run exists → last finished + interval (from completion, not start).
	if got := NextRun(time.Hour, anchor, &fin); !got.Equal(fin.Add(time.Hour)) {
		t.Fatalf("recurring: got %v", got)
	}
}

func TestDueTaskIDs(t *testing.T) {
	now := time.Date(2026, 7, 3, 12, 0, 0, 0, time.UTC)
	anchorOld := now.Add(-2 * time.Hour) // enabled 2h ago
	finRecent := now.Add(-30 * time.Minute)

	tasks := []store.SchedulableTask{
		{ID: 1, IntervalSeconds: 3600, Anchor: anchorOld, LastFinished: nil},        // due: anchor+1h < now
		{ID: 2, IntervalSeconds: 3600, Anchor: anchorOld, LastFinished: &finRecent}, // not due: fin+1h > now
		{ID: 3, IntervalSeconds: 21600, Anchor: anchorOld, LastFinished: nil},       // not due: anchor+6h > now
	}
	ids := dueTaskIDs(tasks, now)
	if len(ids) != 1 || ids[0] != 1 {
		t.Fatalf("due IDs = %v, want [1]", ids)
	}
}