package loop

import (
	"fmt"
	"log/slog"
	"time"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
)

// weekdaysCN maps time.Weekday (0=Sunday) to a Chinese weekday label.
var weekdaysCN = [...]string{"周日", "周一", "周二", "周三", "周四", "周五", "周六"}

// loadTimezone resolves the configured IANA timezone into a *time.Location for
// the per-round time injection. An empty name (or one that fails to load) yields
// nil, disabling injection entirely (backward compatible, graceful degradation).
func loadTimezone(name string, log *slog.Logger) (*time.Location, string) {
	if name == "" {
		return nil, ""
	}
	loc, err := time.LoadLocation(name)
	if err != nil {
		log.Warn("timezone load failed; time injection disabled", "tz", name, "error", err)
		return nil, ""
	}
	return loc, name
}

// currentTimeBlock renders one per-round "current time" system message so the
// model knows the wall-clock time each round (not a first-turn snapshot). It is
// called from assembleContext only when a timezone was configured. It provides
// the raw clock — whether it is "late and time to sleep" is the persona prompt's
// job, not a hard-coded rule here.
func (l *Loop) currentTimeBlock() model.Message {
	now := time.Now().In(l.timeLocation)
	text := fmt.Sprintf("当前时间：%s %s，时区 %s",
		now.Format("2006-01-02 15:04"),
		weekdaysCN[now.Weekday()],
		l.timeZoneName,
	)
	return model.TextMessage(model.RoleSystem, text)
}