import { body, div, span, p, parse } from './main.js'
import { loadself, chatlist, chatload, loadusers, chatcreate } from './api.js'
import { createRoomDisplay, header, parseMessage, parseRoom, parseUser, createSingleLineInput } from './components.js'

async function getUser(user_id) {
    if (data.users[user_id]) {
        return data.users[user_id]
    } else {
        let request = (await loadusers([user_id]))
        if (request.status != 200) {
            location.href = 'login'
        } else {
            data.users[user_id] = request.json[0]
            return request.json[0]
        }
    }
}

async function parseMessageImpl(message) {
    let user = await getUser(message.user_id)
    return parseMessage(message, user)
}

async function onRoomClick(room) {
    for (const room of Object.values(data.rooms)) {
        room.display.style.display = 'none'
        room.button.classList.remove('current')
    } 
    room.display.style.display = ''
    room.button.classList.add('current')
}

async function render() {
    let new_body = 
    body({},
        ...header(false, false, true, data.self.user_id),
        div({id: 'cent'},
            div({id: 'sidebar'},
                span({class: 'ltext'}, 
                    parse("Rooms")
                ),
                createSingleLineInput(
                    {
                        type: 'text',
                        name: 'addRoom',
                        class: 'addRoom input',
                        style: 'flex-grow: 0; width: 80%; margin-left: auto; margin-right: auto;'
                    },
                    async (text) => {
                        let result = (await chatcreate(text))
                        if (result.status != 201) {
                            alert(result.msg)
                            return false
                        } else {
                            return true
                        }
                    }
                ),
            ),
            div({id: 'center'})
        )
    )
    
    document.body.replaceWith(new_body)
}

const data = {
    self: {},
    users: [],
    rooms: {},
}

async function loadRoomPage(room) {

    let request = (await chatload (
        room.newest_msg,
        room.page,
        room.room_id
    ))

    if (request.json == undefined) {
        alert(request.msg)
        return
    }

    let messages = room.display.getElementsByClassName('messages')[0]
    for (const msg of request.json) {
        room.messages.push(msg) 
        messages.appendChild(await parseMessageImpl(msg))
    }

    room.page++

    return request.json.length > 0
}

async function loadRoom(room_id) {
    let room = data.rooms[room_id]

    let batch = []
    for (const user_id of room.users) {
        if (data.users[user_id]) continue
        batch.push(user_id)
    }

    if (batch.length > 1) {
        let request = (await loadusers(batch))
        if (request.status != 200) {
            location.href = '/login'
        } else {
            for (const user of request.json) {
                data.users[user.user_id] = user
            }
        }
    }

    room.display = createRoomDisplay(room, loadRoomPage)

    let displays = document.getElementById("center")
    displays.appendChild(room.display)
    
    let button = parseRoom(room, onRoomClick)
    
    if (displays.children.length > 1) {
        room.display.style.display = 'none'
    } else {
        button.classList.add('current')
    }
    
    room.page = 0
    room.messages = []
    if (room.newest_msg == undefined || room.newest_msg < 0)
        room.newest_msg = Number.MAX_SAFE_INTEGER
    await loadRoomPage(room)
    room.newest_msg = Math.min(
        ...room.messages.map(m => m.message_id)
    )
    room.page = 0
    
    let sidebar = document.getElementById("sidebar")
    sidebar.appendChild(button)
    room.button = button

    if (!room.people) room.people =  room.people = {}
    
    let people = room.display.getElementsByClassName("roomDisplayPeople")[0]
    for (const user_id of room.users) {
        if (room.people[user_id]) continue
        let user = await getUser(user_id)
        let el = parseUser(user)
        people.appendChild(el)
        room.people[user_id] = el
    }

}

async function onMessage(message) {
    let event = JSON.parse(message.data)
    switch (event.type) {
        case "message": {
            let room = data.rooms[event.room_id]
            if (!room) return
            let display = room.display
            let messages = display.getElementsByClassName('messages')[0]
            messages.prepend(await parseMessageImpl(event))
            break;
        }
        case "add": {
            let room = data.rooms[event.room.room_id]
            if (!room) {
                // we are the user being added
                data.rooms[event.room.room_id] = event.room
                loadRoom(event.room.room_id)
            } else {
                let display = room.display
                let people = display.getElementsByClassName('roomDisplayPeople')[0]
                if (!room.people[event.user_id]) {
                    let user = await getUser(event.user_id)
                    let el = parseUser(user)
                    people.appendChild(el)
                    room.people[event.user_id] = el
                }
            }
            break;
        }
        case "leave": {
            let room = data.rooms[event.room_id]
            if (!room) return
            if (room.people[event.user_id]) {
                room.people[event.user_id].remove()
                delete room.people[event.user_id]
            }
            if (event.user_id == data.self.user_id) {
                room.display.remove()
                room.button.remove()
                delete data.rooms[event.room_id]
            } 
            break;
        }
        case "typing": {
            break;
        }
        default: {
            console.warn("unhandled event: " + message.data)
            break;
        }
    }
}

async function init() {

    let request = (await loadself());

    if (request.json == undefined) {
        location.href = '/login'
        return
    }

    data.self = request.json
    data.users[data.self.user_id] = data.self

    render()

    let rooms = (await chatlist());
    if (rooms.json === undefined) {
        alert(rooms.msg)
    } else {
        for (const room of rooms.json) {
            data.rooms[room.room_id] = room 
            loadRoom(room.room_id)
        }
    }

    let socket = new WebSocket(window.location.protocol.replace("http", "ws") + "//" + location.host + "/api/chat/connect")
    socket.addEventListener("message", onMessage);

}


init()