// this one written by claude, it is shit so dont blame me for any misaccuracy LOL

const { readFile } = require("node:fs/promises")
const FILES = [
    "01.json",
    "06.json",
    "10.json"
]
const OPEN_TIME  = "08:00"
const CLOSE_TIME = "17:00"
const DAY_ORDER = {
    "Senin": 1,
    "Selasa": 2,
    "Rabu": 3,
    "Kamis": 4,
    "Jumat": 5,
    "Sabtu": 6,
    "Minggu": 7
}

async function loadFiles()
{
    const results = await Promise.all(FILES.map(async file =>
    {
        const content = await readFile(file, "utf8")
        const json = JSON.parse(content)
        return json.data
    }))
    return results.flat()
}

function parseDateRoom(value)
{
    const match = value.match(/^([^,]+),\s*(\d{2}[:.]\d{2})-(\d{2}[:.]\d{2})\s+\((.*)$/)
    if (!match) return null
    const [ , day, rawStart, rawEnd, rawRoom] = match
    const start = rawStart.replace(".", ":")
    const end   = rawEnd.replace(".", ":")
    const room = rawRoom.endsWith(")") ? rawRoom.slice(0, -1) : rawRoom
    return { day, start, end, room }
}

function timeToMinutes(time)
{
    const [hours, minutes] = time.split(":").map(Number)
    return hours * 60 + minutes
}

function minutesToTime(minutes)
{
    const hours = Math.floor(minutes / 60)
    const mins = minutes % 60
    return `${String(hours).padStart(2, '0')}:${String(mins).padStart(2, '0')}`
}

function buildSchedule(classes)
{
    const schedule = new Map()
    for (const classInfo of classes)
    {
        if (!Array.isArray(classInfo.dates_rooms))
        {
            console.warn(`Skipping ${classInfo.classname}: invalid dates_rooms`)
            continue
        }
        for (const dateRoom of classInfo.dates_rooms)
        {
            const parsed = parseDateRoom(dateRoom)
            if (!parsed)
            {
                console.warn(`Could not parse: ${dateRoom}`)
                continue
            }
            const { day, start, end, room } = parsed
            if (!schedule.has(room))
            {
                schedule.set(room, new Map())
            }
            const roomSchedule = schedule.get(room)
            if (!roomSchedule.has(day))
            {
                roomSchedule.set(day, [])
            }
            roomSchedule.get(day).push({
                start,
                end,
                className: classInfo.classname
            })
        }
    }
    return schedule
}

function buildEmptySchedule(schedule)
{
    const emptySchedule = new Map()
    const dayStartMin = timeToMinutes(OPEN_TIME)
    const dayEndMin = timeToMinutes(CLOSE_TIME)
    
    for (const [room, roomSchedule] of schedule)
    {
        emptySchedule.set(room, new Map())
        
        // Process all days
        for (const day of Object.keys(DAY_ORDER))
        {
            const classes = roomSchedule.get(day) || []
            
            if (classes.length === 0)
            {
                // No classes = room won't be opened that day
                continue
            }
            
            // Sort classes by start time
            const sorted = classes.sort((a, b) => timeToMinutes(a.start) - timeToMinutes(b.start))
            const emptySlots = []
            
            let currentTime = dayStartMin
            
            for (const classInfo of sorted)
            {
                const classStart = timeToMinutes(classInfo.start)
                const classEnd = timeToMinutes(classInfo.end)
                
                // Gap before this class
                if (currentTime < classStart)
                {
                    emptySlots.push({
                        start: minutesToTime(currentTime),
                        end: classInfo.start
                    })
                }
                
                // Move current time to after this class (or keep it if overlapping)
                currentTime = Math.max(currentTime, classEnd)
            }
            
            // Gap after last class
            if (currentTime < dayEndMin)
            {
                emptySlots.push({
                    start: minutesToTime(currentTime),
                    end: CLOSE_TIME
                })
            }
            
            // Only add day if there are empty slots
            if (emptySlots.length > 0)
            {
                emptySchedule.get(room).set(day, emptySlots)
            }
        }
    }
    
    return emptySchedule
}

function formatEmptySchedule(emptySchedule)
{
    const lines = []
    const rooms = [...emptySchedule.keys()].sort((a, b) => a.localeCompare(b))
    
    for (const room of rooms)
    {
        const roomSchedule = emptySchedule.get(room)
        lines.push(`## ${room} \`${OPEN_TIME} - ${CLOSE_TIME}\``)
        
        const days = [...roomSchedule.keys()].sort((a, b) => DAY_ORDER[a] - DAY_ORDER[b])
        
        for (const day of days)
        {
            const emptySlots = roomSchedule.get(day)
            lines.push(`  - **${day}:**`)
            
            for (const slot of emptySlots)
            {
                lines.push(`    - \`${slot.start} - ${slot.end}\` (KOSONG)`)
            }
        }
        lines.push("")
    }
    
    return lines.join("\n")
}

/////////////////
async function main()
{
    const cl = await loadFiles()
    const sc = buildSchedule(cl)
    const emptySchedule = buildEmptySchedule(sc)
    console.log(formatEmptySchedule(emptySchedule))
}

main().catch(error =>
{
    console.error(error)
    process.exitCode = 1
})