vim9script

# collab.vim - collaborative editing adapter for collabd
# requires: bun, collabd daemon running

var bridge_job: job
var bridge_channel: channel
var connected = false
var ready = false
var room = ""
var suppressing = false

# path to bridge script (adjust as needed)
const bridge_script = expand('<sfile>:p:h') .. '/bridge.ts'

def Send(msg: dict<any>)
    if bridge_channel != null
        ch_sendraw(bridge_channel, json_encode(msg) .. "\n")
    endif
enddef

def OnOutput(ch: channel, msg: string)
    if empty(msg)
        return
    endif
    var data: dict<any>
    try
        data = json_decode(msg)
    catch
        return
    endtry

    if data.type == 'ready'
        ready = true
    elseif data.type == 'connected'
        connected = true
        echom '[collab] connected to room: ' .. data.room
    elseif data.type == 'disconnected'
        connected = false
        echom '[collab] disconnected'
    elseif data.type == 'content'
        ApplyRemoteContent(data.text)
    elseif data.type == 'peers'
        echom '[collab] peers: ' .. data.count
    elseif data.type == 'error'
        echoerr '[collab] ' .. data.message
    endif
enddef

def ApplyRemoteContent(content: string)
    if suppressing
        return
    endif
    suppressing = true
    var lines = split(content, "\n", true)
    var view = winsaveview()
    silent! :%delete _
    setline(1, lines)
    winrestview(view)
    suppressing = false
enddef

def SendBuffer()
    if !connected || suppressing
        return
    endif
    var lines = getline(1, '$')
    var content = join(lines, "\n")
    Send({type: 'content', text: content})
enddef

export def Connect(room_name: string)
    if bridge_job != null
        Disconnect()
    endif

    room = room_name
    ready = false
    bridge_job = job_start(['bun', 'run', bridge_script], {
        mode: 'nl',
        out_cb: OnOutput,
        err_io: 'null'
    })
    bridge_channel = job_getchannel(bridge_job)

    # wait for bridge ready signal
    var timeout = 50
    while !ready && timeout > 0
        sleep 10m
        timeout -= 1
    endwhile

    if !ready
        echoerr '[collab] bridge failed to start'
        Disconnect()
        return
    endif

    Send({type: 'connect', room: room_name})

    # set up autocmds to send changes
    augroup CollabVim
        autocmd!
        autocmd TextChanged,TextChangedI * call SendBuffer()
    augroup END
enddef

export def Disconnect()
    if bridge_job != null
        Send({type: 'disconnect'})
        job_stop(bridge_job)
        bridge_job = null
        bridge_channel = null
    endif
    connected = false
    ready = false
    room = ""
    augroup CollabVim
        autocmd!
    augroup END
    echom '[collab] disconnected'
enddef

export def Status()
    if connected
        echom '[collab] connected to room: ' .. room
    else
        echom '[collab] not connected'
    endif
enddef

# commands
command! -nargs=1 CollabJoin call Connect(<q-args>)
command! CollabLeave call Disconnect()
command! CollabStatus call Status()