import type { AbsenceRequest, AbsenceStatus, AbsenceType, HalfDay } from '~/services/dto/absence'

export type BadgeVariant = 'neutral' | 'info' | 'success' | 'warning' | 'danger'

const STATUS_VARIANTS: Record<AbsenceStatus, BadgeVariant> = {
    pending: 'warning',
    approved: 'success',
    rejected: 'danger',
    cancelled: 'neutral',
}

const STATUS_ICONS: Record<AbsenceStatus, string> = {
    pending: 'mdi:clock-outline',
    approved: 'mdi:check-circle-outline',
    rejected: 'mdi:close-circle-outline',
    cancelled: 'mdi:cancel',
}

// Colours used for the calendar bars, keyed by absence type.
const TYPE_COLORS: Record<AbsenceType, string> = {
    cp: '#4A90D9',
    mariage_pacs: '#E91E63',
    conge_parental: '#9C27B0',
    deces: '#607D8B',
    maladie: '#C62828',
}

export function useAbsenceHelpers() {
    const { t } = useI18n()

    function statusLabel(status: AbsenceStatus): string {
        return t(`absences.status.${status}`)
    }

    function statusVariant(status: AbsenceStatus): BadgeVariant {
        return STATUS_VARIANTS[status] ?? 'neutral'
    }

    function statusIcon(status: AbsenceStatus): string {
        return STATUS_ICONS[status] ?? 'mdi:help-circle-outline'
    }

    function typeLabel(type: AbsenceType): string {
        return t(`absences.types.${type}`)
    }

    function typeColor(type: AbsenceType): string {
        return TYPE_COLORS[type] ?? '#9CA3AF'
    }

    function halfDayLabel(half: HalfDay): string {
        return t(`absences.halfDay.${half}`)
    }

    function formatDate(iso: string | null): string {
        if (!iso) return ''
        const d = new Date(iso)
        if (isNaN(d.getTime())) return ''
        const day = String(d.getDate()).padStart(2, '0')
        const month = String(d.getMonth() + 1).padStart(2, '0')
        return `${day}/${month}/${d.getFullYear()}`
    }

    /** Human-readable period with half-day annotations. */
    function formatRange(req: Pick<AbsenceRequest, 'startDate' | 'endDate' | 'startHalfDay' | 'endHalfDay'>): string {
        const start = formatDate(req.startDate)
        const end = formatDate(req.endDate)
        const startSuffix = req.startHalfDay ? ` (${halfDayLabel(req.startHalfDay)})` : ''
        const endSuffix = req.endHalfDay ? ` (${halfDayLabel(req.endHalfDay)})` : ''
        if (start === end) {
            return `${start}${startSuffix}`
        }
        return `${start}${startSuffix} → ${end}${endSuffix}`
    }

    function formatDays(days: number): string {
        const rounded = Math.round(days * 2) / 2
        const unit = rounded > 1 ? t('absences.daysPlural') : t('absences.daySingular')
        return `${rounded} ${unit}`
    }

    return {
        statusLabel,
        statusVariant,
        statusIcon,
        typeLabel,
        typeColor,
        halfDayLabel,
        formatDate,
        formatRange,
        formatDays,
    }
}