'use server'

import { supabase } from '@/lib/supabase'
import { revalidatePath } from 'next/cache'

export async function generateInstantSchedule(prevState: any, formData: FormData) {
    const tanggal = formData.get('tanggal') as string
    const startStr = (formData.get('jam_mulai') as string) || '08:00'
    const endStr = (formData.get('jam_selesai') as string) || '11:00'
    const editedBy = formData.get('edited_by') as string

    if (!tanggal) {
        return { success: false, message: 'Tanggal pelaksanaan harus dipilih.' }
    }

    // Lead time validation: Must be at least tomorrow
    const inputDate = new Date(tanggal)
    const tomorrow = new Date()
    tomorrow.setHours(0, 0, 0, 0)
    tomorrow.setDate(tomorrow.getDate() + 1)

    if (inputDate < tomorrow) {
        return { success: false, message: 'Penjadwalan harus dilakukan minimal 1 hari sebelumnya (Besok atau lusa).' }
    }

    try {
        // 1. Fetch all registered Posyandu
        const { data: allPosyandu, error: fetchErr } = await supabase
            .from('detail_posyandu')
            .select('id, nama_posyandu')

        if (fetchErr) throw fetchErr
        if (!allPosyandu || allPosyandu.length === 0) {
            return { success: false, message: 'Tidak ada data Posyandu terdaftar.' }
        }

        // 2. Shuffle Posyandu randomly
        const shuffled = [...allPosyandu].sort(() => Math.random() - 0.5)

        // 3. Prepare schedules
        // Calculate duration of the first session
        const [hStart, mStart] = startStr.split(':').map(Number)
        const [hEnd, mEnd] = endStr.split(':').map(Number)

        const durationMinutes = (hEnd * 60 + mEnd) - (hStart * 60 + mStart)
        if (durationMinutes <= 0) {
            return { success: false, message: 'Jam selesai harus setelah jam mulai.' }
        }

        const schedulePack = shuffled.map((posyandu, index) => {
            const dayOffset = Math.floor(index / 3)
            const positionInDay = index % 3

            // Calculate date for this posyandu
            const dateObj = new Date(tanggal)
            dateObj.setDate(dateObj.getDate() + dayOffset)
            const currentTanggal = dateObj.toISOString().split('T')[0]

            // Calculate time for this posyandu
            let startTime = new Date(`1970-01-01T${startStr}:00`)
            if (positionInDay > 0) {
                // Add (duration + gap) for each previous session in the same day
                startTime.setMinutes(startTime.getMinutes() + positionInDay * (durationMinutes + 60))
            }

            const sessionEnd = new Date(startTime)
            sessionEnd.setMinutes(sessionEnd.getMinutes() + durationMinutes)

            const pad = (n: number) => n.toString().padStart(2, '0')

            const jam_mulai = `${pad(startTime.getHours())}:${pad(startTime.getMinutes())}:00`
            const jam_selesai = `${pad(sessionEnd.getHours())}:${pad(sessionEnd.getMinutes())}:00`

            return {
                posyandu_id: posyandu.id,
                tanggal: currentTanggal,
                jam_mulai,
                jam_selesai,
                diedit_oleh: editedBy
            }
        })

        // 4. Batch Insert
        const { error: insertErr } = await supabase
            .from('jadwal_posyandu')
            .insert(schedulePack)

        if (insertErr) throw insertErr

        revalidatePath('/dashboard/kelola-jadwal')
        return { success: true, message: `Berhasil menjadwalkan ${shuffled.length} Posyandu!` }

    } catch (error: any) {
        console.error('Scheduling error:', error)
        return { success: false, message: error.message || 'Terjadi kesalahan saat membuat jadwal.' }
    }
}

export async function deleteSchedulesByDate(date: string) {
    try {
        const { error } = await supabase
            .from('jadwal_posyandu')
            .delete()
            .eq('tanggal', date)

        if (error) throw error
        revalidatePath('/dashboard/kelola-jadwal')
        return { success: true, message: 'Jadwal hari tersebut telah dihapus.' }
    } catch (error: any) {
        return { success: false, message: error.message }
    }
}

export async function deleteJadwal(id: string) {
    try {
        const { error } = await supabase
            .from('jadwal_posyandu')
            .delete()
            .eq('id', id)

        if (error) throw error
        revalidatePath('/dashboard/kelola-jadwal')
        return { success: true, message: 'Jadwal berhasil dihapus.' }
    } catch (error: any) {
        return { success: false, message: error.message }
    }
}

export async function updateJadwal(prevState: any, formData: FormData) {
    const id = formData.get('id') as string
    const tanggal = formData.get('tanggal') as string
    const jam_mulai = formData.get('jam_mulai') as string
    const jam_selesai = formData.get('jam_selesai') as string
    const editedBy = formData.get('edited_by') as string

    if (!id || !tanggal || !jam_mulai || !jam_selesai) {
        return { success: false, message: 'Field wajib tidak boleh kosong.' }
    }

    try {
        const { error } = await supabase
            .from('jadwal_posyandu')
            .update({
                tanggal,
                jam_mulai: jam_mulai.length === 5 ? `${jam_mulai}:00` : jam_mulai,
                jam_selesai: jam_selesai.length === 5 ? `${jam_selesai}:00` : jam_selesai,
                diedit_oleh: editedBy,
                updated_at: new Date().toISOString()
            })
            .eq('id', id)

        if (error) throw error

        revalidatePath('/dashboard/kelola-jadwal')
        return { success: true, message: 'Jadwal berhasil diperbarui!' }
    } catch (error: any) {
        console.error('Update error:', error)
        return { success: false, message: error.message || 'Gagal memperbarui jadwal.' }
    }
}

export async function getOccupiedSlots(date: string) {
    try {
        const { data, error } = await supabase
            .from('jadwal_posyandu')
            .select('jam_mulai, jam_selesai, posyandu_id')
            .eq('tanggal', date)

        if (error) throw error

        return {
            success: true,
            slots: data.map(s => ({
                start: s.jam_mulai.slice(0, 5),
                end: s.jam_selesai.slice(0, 5),
                posyandu_id: s.posyandu_id
            }))
        }
    } catch (error: any) {
        return { success: false, slots: [] }
    }
}

export async function archiveSchedulesByMonth(month: number, year: number) {
    try {
        const startOfMonth = `${year}-${String(month + 1).padStart(2, '0')}-01`
        const endOfMonth = new Date(year, month + 1, 0).toISOString().split('T')[0]

        const { data: targets, error: fetchErr } = await supabase
            .from('jadwal_posyandu')
            .select('id, diedit_oleh')
            .gte('tanggal', startOfMonth)
            .lte('tanggal', endOfMonth)
            .not('diedit_oleh', 'ilike', '[HISTORY]%')

        if (fetchErr) throw fetchErr
        if (!targets || targets.length === 0) return { success: true, message: 'Tidak ada jadwal aktif untuk diarsipkan.' }

        // Update each target to have [HISTORY] prefix
        for (const item of targets) {
            const { error: updErr } = await supabase
                .from('jadwal_posyandu')
                .update({ diedit_oleh: `[HISTORY] ${item.diedit_oleh}` })
                .eq('id', item.id)
            if (updErr) throw updErr
        }

        revalidatePath('/dashboard/kelola-jadwal')
        return { success: true, message: 'Seluruh jadwal bulan ini telah dipindahkan ke Histori!' }
    } catch (error: any) {
        return { success: false, message: error.message || 'Gagal mengarsipkan jadwal.' }
    }
}

export async function deleteAllHistory() {
    try {
        const { error } = await supabase
            .from('jadwal_posyandu')
            .delete()
            .ilike('diedit_oleh', '[HISTORY]%')

        if (error) throw error

        revalidatePath('/dashboard/kelola-jadwal')
        return { success: true, message: 'Seluruh riwayat jadwal berhasil dihapus permanen!' }
    } catch (error: any) {
        return { success: false, message: error.message || 'Gagal menghapus histori.' }
    }
}

export async function getPetugasLokalByPosyandu(posyanduId: string) {
    try {
        const { data, error } = await supabase
            .from('petugas_posyandu_lokal')
            .select('nama_petugas, nomor_hp, jabatan')
            .eq('posyandu_id', posyanduId)

        if (error) throw error
        return { success: true, petugas: data }
    } catch (error: any) {
        return { success: false, petugas: [] }
    }
}