---
--- Created by Petereo.
--- DateTime: 19/11/2019 18:12
---
_osname = 'Petereo OS'
_osversion = "0.1"

function require(pkg)
    if type(pkg) ~= 'string' then return nil end
    return _ENV[pkg] or _G[pkg]
end
--- Component ---
setmetatable(component,{__index = function(_,k) return component.getPrimary(k) end})
function component.getPrimary(dev)
    if dev == 'filesystem' then
        return component.proxy(computer.getBootAddress())
    end
    for k,v in component.list() do
        if v == dev then
            return component.proxy(k)
        end
    end
end

--- Graphics ---

g = {}
function g.bind()
    local screen = component.list('screen')()
    return component.gpu.bind(screen)
end

function g.available()
    local gpu, screen = component.list('gpu')(),component.list('screen')()
    return(gpu and screen)
end

function g.copy(x,y,w,h,a,b)
    component.gpu.copy(x,y,w,h,a,b)
end

function g.getResolution()
    return component.gpu.getResolution()
end

function g.setResolution(w,h)
    return component.gpu.setResolution(w,h)
end

function g.getDepth()
    return component.gpu.getDepth()
end

function g.setBG(color)
    return component.gpu.setBG(color)
end

function g.setFG(color)
    return component.gpu.setFG(color)
end

function g.fill(x,y,w,h)
    return component.gpu.fill(x,y,w,h,' ')
end

function g.fillc(x,y,w,h,ch)
    return component.gpu.fill(x,y,w,h,ch)
end

function g.drawText(x,y,str)
    return component.gpu.set(x,y,str)
end

local w,h = g.getResolution()
local cx,cy = (w/2),(h/2)


--+-+-+-+-+ Filesystem +-+-+-+-+--
f = {}
f.addr = computer.getBootAddress()
function f.setBootAddress(addr)
    f.addr = addr
end
function f.open(file,mode)
    return component.filesystem.open(file,mode)
end
function f.read(handle)
    return component.filesystem.read(handle,math.huge)
end
function f.write(handle,str)
    return component.filesystem.write(handle,str)
end
function f.close(handle)
    return component.filesystem.close(handle)
end
function f.list(dir)
    return component.filesystem.list(dir or '/')
end
function f.mkdir(dir)
    return component.filesystem.makeDirectory(dir)
end
function f.rename(name1,name2)
    return component.filesystem.rename(name1,name2)
end
function f.remove(dir)
    return component.filesystem.remove(dir)
end
function f.loadfile(file)
    local hdl,err = f.open(file,'r')
    if not hdl then error(err) end
    local buffer = ''
    repeat
        local data, err_read = f.read(hdl)
        if not data and err_read then error(err_read) end
        buffer = buffer .. (data or '')
    until not data
    f.close(hdl)
    return load(buffer,'='..file)
end
function f.runfile(file,argc,args)
    local prog,err = f.loadfile(file)
    if prog then
        local res = table.pack(xpcall(prog,function(...) return debug.traceback() end,argc,args))
        if res[1] then
            return table.unpack(res,2,res.n)
        else
            error(res[2])
        end
    else
        error(err)
    end
end
f.load = f.loadfile
f.run = f.runfile

--- Error ---

std_error = error
function error(msg)
    g.setFG(0xFFFFFF)
    g.setBG(0x000000)
    g.fill(1,1,w,h)
    -- write to screen
    local line = 1
    local prev = 1
    for w in string.gmatch(msg,'()\n') do
        g.drawText(1,line,msg:sub(prev,w-1))
        prev = w+1
        line = line+1
    end
    g.drawText(1,line,msg:sub(prev))
    -- write to log
    local hdl,errf = f.open('error_log.txt','w')
    if hdl then
        f.write(hdl,msg..'\n')
    end
    f.close(hdl)
    repeat
        local e,addr,char,code = computer.pullSignal()
    until e == 'key_down' and code == 28
    computer.shutdown(true)
end

-- Shell --

g.fill(1,1,w,h)

function tabletostr(tabl)
    local retval = ''
    for i=1, #tabl do
        retval = retval .. tabl[i]
    end
    return retval
end

function strtotable(str)
    local retval = {}
    for i = 1, #str do
        table.insert(retval,str:sub(i,i))
    end
    return retval
end

function serialize (o, ind)
    ind = ind or 1
    local indn = 0
    local indent = ''
    while indn < ind do
        indent = indent .. '  '
        indn =  indn + 1
    end
    local retstr = ''
    if type(o) == "number" then
        retstr = retstr .. o .. ''
    elseif type(o) == "boolean" then
        retstr = retstr .. tostring(o)
    elseif type(o) == "string" then
        retstr = retstr .. string.format("%q", o) .. ''
    elseif type(o) == "table" then
        retstr = retstr .. '{\n'
        for k,v in pairs(o) do
            retstr = retstr .. indent .. '' .. k .. '='
            retstr = retstr .. serialize(v,ind+1)
            retstr = retstr .. ',\n'
        end
        retstr = retstr .. indent:sub(1,indent:len()-2) .. '}'
    else
        retstr = retstr .. '<'..type(o)..'>'
    end
    return retstr
end

-- Console --

local console_header = '$ '

--- output buffer

local out = {} -- output system
out.history = {} -- output lines history
out.historysize = h*10 -- history size
out.coutl = {} -- current output line
out.line = 1 -- current line
out.lptr = 1 -- line pointer to history table
out.col = 1 -- current column
out.topline = 0 -- last line in history

local function outl()
    if out.topline ~= 0 then return end
    g.fill(out.col,out.line,w,1)
    local strout = tabletostr(out.coutl)
    g.drawText(1,out.line,strout)
end
function cout(str)
    str = tostring(str)
    if #str > 1 then
        local atab = strtotable(str)
        for i=1, #atab do
            table.insert(out.coutl,out.col,atab[i])
            out.col = out.col + 1
        end
    else
        table.insert(out.coutl,out.col,str)
        out.col = out.col + 1
    end
    outl()
end
local function backspace()
    if out.col <= #console_header+1 then
        out.col = #console_header+1
        return
    end
    table.remove(out.coutl,out.col-1)
    out.col = out.col - 1
    outl()
end
local function scrollUp()
    if #out.history >= h then
        if out.topline == 0 then outl() end
        out.topline = out.topline + 1
        if out.topline+(h-1) > #out.history then
            out.topline = #out.history - h+1
            return false
        end
        g.copy(1,1,w,h-1,0,1)
        g.fill(1,1,w,1)
        g.drawText(1,1,out.history[out.topline + (h-1)])
        return true
    end
end
local function scrollDown()
    if #out.history >= h then
        out.topline = out.topline - 1
        if out.topline < 0 then
            out.topline = 0
            return false
        end
        if out.topline == 0 then
            g.copy(1,2,w,h-1,0,-1)
            g.fill(1,h,w,1)
            outl()
        else
            g.copy(1,2,w,h-1,0,-1)
            g.fill(1,h,w,1)
            g.drawText(1,h,out.history[out.topline])
        end
        return true
    end
end

local function newline()
    local atab = tabletostr(out.coutl)
    table.insert(out.history,1,atab)
    if #out.history > out.historysize then
        table.remove(out.history)
    end
    out.line = out.line + 1
    out.lptr = out.lptr + 1
    if out.line > h then
        out.line = h
        if out.topline == 0 then
            g.copy(1,2,w,h-1,0,-1)
            g.fill(1,h,w,1)
        end
    end
    out.col = 1
    out.coutl = {}
end

function print(str)
    if type(str) == 'table' then
        str = serialize(str)
    else
        str = tostring(str)
    end
    local prev = 1
    for w in string.gmatch(str,'()\n') do
        cout(str:sub(prev,w-1))
        prev = w+1
        newline()
    end
    cout(str:sub(prev))
    newline()
end

local function main()
    local curloc = 1
    local curstate = false

    local function blinkcursor()
        if out.topline ~= 0 then return end
        if curstate then
            g.drawText(out.col,out.line,unicode.char(0x2588))
        else
            outl()
        end
        curstate = not curstate
    end

    -- command history --

    local cmdhistory = {}
    local cmdhlen = 20
    local cmdhbrowse = 0

    --- todo ---

    print(_osname..' '.._osversion.. '(' ..math.floor(computer.totalMemory() / 1000)..'k RAM)\n\n')
    cout(console_header)
    while true do

        local evt = table.pack(computer.pullSignal(0.4))
        if evt[1] == 'key_down' then
            if evt[4] == 88 then computer.shutdown(true) end -- F12 to restart
            if evt[4] == 68 then computer.shutdown() end -- F10 to shutdown
            -- command
            if evt[4] == 28 then -- enter key
                outl()
                -- convert to string
                local cinput = tabletostr(out.coutl)
                cinput = cinput:sub(#console_header+1)
                -- add to history
                if cinput ~= '' then
                    table.insert(cmdhistory,1,cinput)
                end
                if #cmdhistory > cmdhlen then table.remove(cmdhistory) end
                -- parse command
                local luacmd = cinput
                --[[local args = {}
                local argc = 0
                local cmdget = false
                local command = ''
                cinput = string.gsub(cinput,'%s',unicode.char(0x2591))
                for p in string.gmatch(cinput,'(.-)'..unicode.char(0x2591)) do
                  if not cmdget then
                    command = p
                    cmdget = true
                  else
                    table.insert(args,p)
                    argc = argc + 1
                  end
                end]]
                -- execute
                newline()
                cmdhbrowse = 0
                local loaded,lderr = load(luacmd,'=cinput')
                if loaded then
                    local res,err = xpcall(loaded,function(msg) return msg ..'\n'.. debug.traceback() end)
                    if not res and err then
                        print(err)
                    end
                elseif not loaded and lderr then
                    print(lderr)
                else
                    print('Unknown Command')
                end
                -- done
                cout(console_header)
            elseif evt[4] == 14 then -- backspace
                curstate = true -- keep cursor displayed
                backspace()
            elseif evt[4] == 200 then -- up key
                out.coutl = {}
                out.col = 1
                if cmdhbrowse >= #cmdhistory then cmdhbrowse = #cmdhistory else
                    cmdhbrowse = cmdhbrowse + 1 end
                local hval = cmdhistory[cmdhbrowse]
                cout(console_header)
                cout(hval)
            elseif evt[4] == 208 then -- down key
                out.coutl = {}
                out.col = 1
                if cmdhbrowse <= 1 then cmdhbrowse = 1 else
                    cmdhbrowse = cmdhbrowse - 1 end
                local hval = cmdhistory[cmdhbrowse]
                cout(console_header)
                cout(hval)
            elseif evt[4] == 203 then -- left key
                curstate = true -- keep cursor displayed
                out.col = out.col - 1
                if out.col < #console_header+1 then
                    out.col = #console_header+1
                end
                outl()
            elseif evt[4] == 205 then --  right key
                curstate = true -- keep cursor displayed
                out.col = out.col + 1
                if out.col > #out.coutl+1 then
                    out.col = #out.coutl+1
                end
                outl()
            elseif evt[4] == 199 then -- home
                curstate = true
                out.col = #console_header+1
                outl()
            elseif evt[4] == 207 then -- end
                curstate = true
                out.col = #out.coutl+1
                outl()
            elseif evt[3] ~= 0 then -- printable keys
                curstate = true -- keep cursor displayed
                local char = string.char(evt[3])
                cout(char)
            end
        elseif evt[1] == 'scroll' then
            if evt[5] > 0 then -- scroll up
                scrollUp()
            elseif evt[5] < 0 then -- scroll down
                scrollDown()
            end
        end
        blinkcursor()
    end
end

    if component.filesystem.exists('autorun.lua') then
        f.runfile('autorun.lua')
    end

local res,err = xpcall(main,function(msg) return msg ..'\n'.. debug.traceback() end)
if not res and err then
    error(err)
end
computer.shutdown()