Computercraft Streaming Music Program (Version 2.1)

local api_base_url = "https://ipod-2to6magyna-uc.a.run.app/"
local version = "2.1"

local width, height = term.getSize()
local tab = 1

local waiting_for_input = false
local last_search = nil
local last_search_url = nil
local search_results = nil
local search_error = false
local in_search_result = false
local clicked_result = nil

local playing = false
local queue = {}
local now_playing = nil
local looping = 0
local volume = 1.5

local playing_id = nil
local last_download_url = nil
local playing_status = 0
local is_loading = false
local is_error = false;

local player_handle = nil
local start = nil
local pcm = nil
local size = nil
local decoder = require "cc.audio.dfpwm".make_decoder()
local needs_next_chunk = 0
local buffer

local speakers = { peripheral.find("speaker") }
if #speakers == 0 then
    error("No speakers attached. You need to connect a speaker to this computer. If this is an Advanced Noisy Pocket Computer, then this is a bug, and you should try restarting your Minecraft game.", 0)
end

function redrawScreen()
    if waiting_for_input then
        return
    end

    term.setCursorBlink(false)  -- Make sure cursor is off when redrawing
    -- Clear the screen
    term.setBackgroundColor(colors.black)
    term.clear()

    --Draw the three top tabs
    term.setCursorPos(1,1)
    term.setBackgroundColor(colors.gray)
    term.clearLine()

    tabs = {" Now Playing ", " Search "}

    for i=1,#tabs,1 do
        if tab == i then
            term.setTextColor(colors.black)
            term.setBackgroundColor(colors.white)
        else
            term.setTextColor(colors.white)
            term.setBackgroundColor(colors.gray)
        end

        term.setCursorPos((math.floor((width/#tabs)*(i-0.5)))-math.ceil(#tabs[i]/2)+1, 1)
        term.write(tabs[i])
    end

    if tab == 1 then
        drawNowPlaying()
    elseif tab == 2 then
        drawSearch()
    end
end

function drawNowPlaying()
    if now_playing ~= nil then
        term.setBackgroundColor(colors.black)
        term.setTextColor(colors.white)
        term.setCursorPos(2,3)
        term.write(now_playing.name)
        term.setTextColor(colors.lightGray)
        term.setCursorPos(2,4)
        term.write(now_playing.artist)
    else
        term.setBackgroundColor(colors.black)
        term.setTextColor(colors.lightGray)
        term.setCursorPos(2,3)
        term.write("Not playing")
    end

    if is_loading == true then
        term.setTextColor(colors.gray)
        term.setBackgroundColor(colors.black)
        term.setCursorPos(2,5)
        term.write("Loading...")
    elseif is_error == true then
        term.setTextColor(colors.red)
        term.setBackgroundColor(colors.black)
        term.setCursorPos(2,5)
        term.write("Network error")
    end

    term.setTextColor(colors.white)
    term.setBackgroundColor(colors.gray)

    if playing then
        term.setCursorPos(2, 6)
        term.write(" Stop ")
    else
        if now_playing ~= nil or #queue > 0 then
            term.setTextColor(colors.white)
            term.setBackgroundColor(colors.gray)
        else
            term.setTextColor(colors.lightGray)
            term.setBackgroundColor(colors.gray)
        end
        term.setCursorPos(2, 6)
        term.write(" Play ")
    end

    if now_playing ~= nil or #queue > 0 then
        term.setTextColor(colors.white)
        term.setBackgroundColor(colors.gray)
    else
        term.setTextColor(colors.lightGray)
        term.setBackgroundColor(colors.gray)
    end
    term.setCursorPos(2 + 7, 6)
    term.write(" Skip ")

    if looping ~= 0 then
        term.setTextColor(colors.black)
        term.setBackgroundColor(colors.white)
    else
        term.setTextColor(colors.white)
        term.setBackgroundColor(colors.gray)
    end
    term.setCursorPos(2 + 7 + 7, 6)
    if looping == 0 then
        term.write(" Loop Off ")
    elseif looping == 1 then
        term.write(" Loop Queue ")
    else
        term.write(" Loop Song ")
    end

    term.setCursorPos(2,8)
    paintutils.drawBox(2,8,25,8,colors.gray)
    local width = math.floor(24 * (volume / 3) + 0.5)-1
    if not (width == -1) then
        paintutils.drawBox(2,8,2+width,8,colors.white)
    end
    if volume < 0.6 then
        term.setCursorPos(2+width+2,8)
        term.setBackgroundColor(colors.gray)
        term.setTextColor(colors.white)
    else
        term.setCursorPos(2+width-3-(volume == 3 and 1 or 0),8)
        term.setBackgroundColor(colors.white)
        term.setTextColor(colors.black)
    end
    term.write(math.floor(100 * (volume / 3) + 0.5) .. "%")

    if #queue > 0 then
        term.setBackgroundColor(colors.black)
        for i=1,#queue do
            term.setTextColor(colors.white)
            term.setCursorPos(2,10 + (i-1)*2)
            term.write(queue[i].name)
            term.setTextColor(colors.lightGray)
            term.setCursorPos(2,11 + (i-1)*2)
            term.write(queue[i].artist)
        end
    end
end

function drawSearch()
    -- Search bar
    paintutils.drawFilledBox(2,3,width-1,5,colors.lightGray)
    term.setBackgroundColor(colors.lightGray)
    term.setCursorPos(3,4)
    term.setTextColor(colors.black)
    term.write(last_search or "Search...")

    --Search results
    if search_results ~= nil then
        term.setBackgroundColor(colors.black)
        for i=1,#search_results do
            term.setTextColor(colors.white)
            term.setCursorPos(2,7 + (i-1)*2)
            term.write(search_results[i].name)
            term.setTextColor(colors.lightGray)
            term.setCursorPos(2,8 + (i-1)*2)
            term.write(search_results[i].artist)
        end
    else
        term.setCursorPos(2,7)
        term.setBackgroundColor(colors.black)
        if search_error == true then
            term.setTextColor(colors.red)
            term.write("Network error")
        elseif last_search_url ~= nil then
            term.setTextColor(colors.lightGray)
            term.write("Searching...")
        else
            term.setCursorPos(1,7)
            term.setTextColor(colors.lightGray)
            print("Tip: You can paste YouTube video or playlist links.")
        end
    end

    --fullscreen song options
    if in_search_result == true then
        term.setBackgroundColor(colors.black)
        term.clear()
        term.setCursorPos(2,2)
        term.setTextColor(colors.white)
        term.write(search_results[clicked_result].name)
        term.setCursorPos(2,3)
        term.setTextColor(colors.lightGray)
        term.write(search_results[clicked_result].artist)

        term.setBackgroundColor(colors.gray)
        term.setTextColor(colors.white)

        term.setCursorPos(2,6)
        term.clearLine()
        term.write("Play now")

        term.setCursorPos(2,8)
        term.clearLine()
        term.write("Play next")

        term.setCursorPos(2,10)
        term.clearLine()
        term.write("Add to queue")

        term.setCursorPos(2,13)
        term.clearLine()
        term.write("Cancel")
    end
end

function uiLoop()
    redrawScreen()

    while true do
        if waiting_for_input then
            parallel.waitForAny(
                function()
                    term.setCursorPos(3,4)
                    term.setBackgroundColor(colors.white)
                    term.setTextColor(colors.black)
                    local input = read()

                    if string.len(input) > 0 then
                        last_search = input
                        last_search_url = api_base_url .. "?v=" .. version .. "&search=" .. textutils.urlEncode(input)
                        http.request(last_search_url)
                        search_results = nil
                        search_error = false
                    else
                        last_search = nil
                        last_search_url = nil
                        search_results = nil
                        search_error = false
                    end

                    waiting_for_input = false
                    os.queueEvent("redraw_screen")
                end,
                function()
                    while waiting_for_input do
                        local event, button, x, y = os.pullEvent("mouse_click")
                        if y < 3 or y > 5 or x < 2 or x > width-1 then
                            waiting_for_input = false
                            os.queueEvent("redraw_screen")
                            break
                        end
                    end
                end
            )
        else
            parallel.waitForAny(
                function()
                    local event, button, x, y = os.pullEvent("mouse_click")

                    if button == 1 then
                        -- Tabs
                        if in_search_result == false then
                            if y == 1 then
                                if x < width/2 then
                                    tab = 1
                                else
                                    tab = 2
                                end
                                redrawScreen()
                            end
                        end

                        if tab == 2 and in_search_result == false then
                            -- Search box click
                            if y >= 3 and y <= 5 and x >= 1 and x <= width-1 then
                                paintutils.drawFilledBox(2,3,width-1,5,colors.white)
                                term.setBackgroundColor(colors.white)
                                waiting_for_input = true
                            end

                            -- Search result click
                            if search_results then
                                for i=1,#search_results do
                                    if y == 7 + (i-1)*2 or y == 8 + (i-1)*2 then
                                        term.setBackgroundColor(colors.white)
                                        term.setTextColor(colors.black)
                                        term.setCursorPos(2,7 + (i-1)*2)
                                        term.clearLine()
                                        term.write(search_results[i].name)
                                        term.setTextColor(colors.gray)
                                        term.setCursorPos(2,8 + (i-1)*2)
                                        term.clearLine()
                                        term.write(search_results[i].artist)
                                        sleep(0.2)
                                        in_search_result = true
                                        clicked_result = i
                                        redrawScreen()
                                    end
                                end
                            end
                        elseif tab == 2 and in_search_result == true then
                            -- Search result menu clicks

                            term.setBackgroundColor(colors.white)
                            term.setTextColor(colors.black)

                            if y == 6 then
                                term.setCursorPos(2,6)
                                term.clearLine()
                                term.write("Play now")
                                sleep(0.2)
                                in_search_result = false
                                for _, speaker in ipairs(speakers) do
                                    speaker.stop()
                                    os.queueEvent("playback_stopped")
                                end
                                playing = true
                                is_error = false
                                playing_id = nil
                                if search_results[clicked_result].type == "playlist" then
                                    now_playing = search_results[clicked_result].playlist_items[1]
                                    queue = {}
                                    if #search_results[clicked_result].playlist_items > 1 then
                                        for i=2, #search_results[clicked_result].playlist_items do
                                            table.insert(queue, search_results[clicked_result].playlist_items[i])
                                        end
                                    end
                                else
                                    now_playing = search_results[clicked_result]
                                end
                                os.queueEvent("audio_update")
                            end

                            if y == 8 then
                                term.setCursorPos(2,8)
                                term.clearLine()
                                term.write("Play next")
                                sleep(0.2)
                                in_search_result = false
                                if search_results[clicked_result].type == "playlist" then
                                    for i = #search_results[clicked_result].playlist_items, 1, -1 do
                                        table.insert(queue, 1, search_results[clicked_result].playlist_items[i])
                                    end
                                else
                                    table.insert(queue, 1, search_results[clicked_result])
                                end
                                os.queueEvent("audio_update")
                            end

                            if y == 10 then
                                term.setCursorPos(2,10)
                                term.clearLine()
                                term.write("Add to queue")
                                sleep(0.2)
                                in_search_result = false
                                if search_results[clicked_result].type == "playlist" then
                                    for i = 1, #search_results[clicked_result].playlist_items do
                                        table.insert(queue, search_results[clicked_result].playlist_items[i])
                                    end
                                else
                                    table.insert(queue, search_results[clicked_result])
                                end
                                os.queueEvent("audio_update")
                            end

                            if y == 13 then
                                term.setCursorPos(2,13)
                                term.clearLine()
                                term.write("Cancel")
                                sleep(0.2)
                                in_search_result = false
                            end

                            redrawScreen()
                        elseif tab == 1 and in_search_result == false then
                            -- Now playing tab clicks

                            if y == 6 then
                                -- Play/stop button
                                if x >= 2 and x < 2 + 6 then
                                    if playing or now_playing ~= nil or #queue > 0 then
                                        term.setBackgroundColor(colors.white)
                                        term.setTextColor(colors.black)
                                        term.setCursorPos(2, 6)
                                        if playing then
                                            term.write(" Stop ")
                                        else
                                            term.write(" Play ")
                                        end
                                        sleep(0.2)
                                    end
                                    if playing then
                                        playing = false
                                        for _, speaker in ipairs(speakers) do
                                            speaker.stop()
                                            os.queueEvent("playback_stopped")
                                        end
                                        playing_id = nil
                                        is_loading = false
                                        is_error = false
                                        os.queueEvent("audio_update")
                                    elseif now_playing ~= nil then
                                        playing_id = nil
                                        playing = true
                                        is_error = false
                                        os.queueEvent("audio_update")
                                    elseif #queue > 0 then
                                        now_playing = queue[1]
                                        table.remove(queue, 1)
                                        playing_id = nil
                                        playing = true
                                        is_error = false
                                        os.queueEvent("audio_update")
                                    end
                                end

                                -- Skip button
                                if x >= 2 + 7 and x < 2 + 7 + 6 then
                                    if now_playing ~= nil or #queue > 0 then
                                        term.setBackgroundColor(colors.white)
                                        term.setTextColor(colors.black)
                                        term.setCursorPos(2 + 7, 6)
                                        term.write(" Skip ")
                                        sleep(0.2)

                                        is_error = false
                                        if playing then
                                            for _, speaker in ipairs(speakers) do
                                                speaker.stop()
                                                os.queueEvent("playback_stopped")
                                            end
                                        end
                                        if #queue > 0 then
                                            if looping == 1 then
                                                table.insert(queue, now_playing)
                                            end
                                            now_playing = queue[1]
                                            table.remove(queue, 1)
                                            playing_id = nil
                                        else
                                            now_playing = nil
                                            playing = false
                                            is_loading = false
                                            is_error = false
                                            playing_id = nil
                                        end
                                        os.queueEvent("audio_update")
                                    end
                                end

                                -- Loop button
                                if x >= 2 + 7 + 7 and x < 2 + 7 + 7 + 12 then
                                    if looping == 0 then
                                        looping = 1
                                    elseif looping == 1 then
                                        looping = 2
                                    else
                                        looping = 0
                                    end
                                end
                            end

                            if y == 8 then
                                -- Volume slider
                                if x >= 1 and x < 2 + 24 then
                                    volume = (x - 1) / 24 * 3

                                    -- for _, speaker in ipairs(speakers) do
                                    --  speaker.stop()
                                    --  os.queueEvent("playback_stopped")
                                    -- end
                                    -- playing_id = nil
                                    -- os.queueEvent("audio_update")
                                end
                            end

                            redrawScreen()
                        end
                    end
                end,
                function()
                    local event, button, x, y = os.pullEvent("mouse_drag")

                    if button == 1 then

                        if tab == 1 and in_search_result == false then

                            if y >= 7 and y <= 9 then
                                -- Volume slider
                                if x >= 1 and x < 2 + 24 then
                                    volume = (x - 1) / 24 * 3

                                    -- for _, speaker in ipairs(speakers) do
                                    --  speaker.stop()
                                    --  os.queueEvent("playback_stopped")
                                    -- end
                                    -- playing_id = nil
                                    -- os.queueEvent("audio_update")
                                end
                            end

                            redrawScreen()
                        end
                    end
                end,
                function()
                    local event = os.pullEvent("redraw_screen")

                    redrawScreen()
                end
            )
        end
    end
end

function audioLoop()
    while true do

        -- AUDIO
        if playing and now_playing then
            local thisnowplayingid = now_playing.id
            if playing_id ~= thisnowplayingid then
                playing_id = thisnowplayingid
                last_download_url = api_base_url .. "?v=" .. version .. "&id=" .. textutils.urlEncode(playing_id)
                playing_status = 0
                needs_next_chunk = 1

                http.request({url = last_download_url, binary = true})
                is_loading = true

                os.queueEvent("redraw_screen")
                os.queueEvent("audio_update")
            elseif playing_status == 1 and needs_next_chunk == 1 then

                while true do
                    local chunk = player_handle.read(size)
                    if not chunk then
                        if looping == 2 or (looping == 1 and #queue == 0) then
                            playing_id = nil
                        elseif looping == 1 and #queue > 0 then
                            table.insert(queue, now_playing)
                            now_playing = queue[1]
                            table.remove(queue, 1)
                            playing_id = nil
                        else
                            if #queue > 0 then
                                now_playing = queue[1]
                                table.remove(queue, 1)
                                playing_id = nil
                            else
                                now_playing = nil
                                playing = false
                                playing_id = nil
                                is_loading = false
                                is_error = false
                            end
                        end

                        os.queueEvent("redraw_screen")

                        player_handle.close()
                        needs_next_chunk = 0
                        break
                    else
                        if start then
                            chunk, start = start .. chunk, nil
                            size = size + 4
                        end

                        buffer = decoder(chunk)

                        local fn = {}
                        for i, speaker in ipairs(speakers) do
                            fn[i] = function()
                                local name = peripheral.getName(speaker)
                                if #speakers > 1 then
                                    if speaker.playAudio(buffer, volume) then
                                        parallel.waitForAny(
                                            function()
                                                repeat until select(2, os.pullEvent("speaker_audio_empty")) == name
                                            end,
                                            function()
                                                local event = os.pullEvent("playback_stopped")
                                                return
                                            end
                                        )
                                        if not playing or playing_id ~= thisnowplayingid then
                                            return
                                        end
                                    end
                                else
                                    while not speaker.playAudio(buffer, volume) do
                                        parallel.waitForAny(
                                            function()
                                                repeat until select(2, os.pullEvent("speaker_audio_empty")) == name
                                            end,
                                            function()
                                                local event = os.pullEvent("playback_stopped")
                                                return
                                            end
                                        )
                                        if not playing or playing_id ~= thisnowplayingid then
                                            return
                                        end
                                    end
                                end
                                if not playing or playing_id ~= thisnowplayingid then
                                    return
                                end
                            end
                        end

                        local ok, err = pcall(parallel.waitForAll, table.unpack(fn))
                        if not ok then
                            needs_next_chunk = 2
                            is_error = true
                            break
                        end

                        -- If we're not playing anymore, exit the chunk processing loop
                        if not playing or playing_id ~= thisnowplayingid then
                            break
                        end
                    end
                end
                os.queueEvent("audio_update")
            end
        end

        os.pullEvent("audio_update")
    end
end

function httpLoop()
    while true do
        parallel.waitForAny(
            function()
                local event, url, handle = os.pullEvent("http_success")

                if url == last_search_url then
                    search_results = textutils.unserialiseJSON(handle.readAll())
                    os.queueEvent("redraw_screen")
                end
                if url == last_download_url then
                    is_loading = false
                    player_handle = handle
                    start = handle.read(4)
                    size = 16 * 1024 - 4
                    playing_status = 1
                    os.queueEvent("redraw_screen")
                    os.queueEvent("audio_update")
                end
            end,
            function()
                local event, url = os.pullEvent("http_failure")

                if url == last_search_url then
                    search_error = true
                    os.queueEvent("redraw_screen")
                end
                if url == last_download_url then
                    is_loading = false
                    is_error = true
                    playing = false
                    playing_id = nil
                    os.queueEvent("redraw_screen")
                    os.queueEvent("audio_update")
                end
            end
        )
    end
end

parallel.waitForAny(uiLoop, audioLoop, httpLoop)