gist

-- Gist Client for ComputerCraft
-- version 1.1
-- Matti Vapa, 2013
-- License: MIT
-- the client uses JSON4LUA module for parsing JSON (provided below)
-- client code starts around line 270

-- v1.1 noticed that you don't need to escape single quotes, per json specifications
-- v1.0 first version


-----------------------------------------------------------------------------
-- JSON4Lua: JSON encoding / decoding support for the Lua language.
-- json Module.
-- Author: Craig Mason-Jones
-- Homepage: http://json.luaforge.net/
-- Version: 0.9.40
-- This module is released under the MIT License (MIT).

-- edited for brevity

local base = _G
local decode_scanArray
local decode_scanComment
local decode_scanConstant
local decode_scanNumber
local decode_scanObject
local decode_scanString
local decode_scanWhitespace
local encodeString
local isArray
local isEncodable

local function encode (v)
  -- Handle nil values
  if v==nil then
    return "null"
  end

  local vtype = base.type(v)

  -- Handle strings
  if vtype=='string' then
    return '"' .. encodeString(v) .. '"'        -- Need to handle encoding in string
  end

  -- Handle booleans
  if vtype=='number' or vtype=='boolean' then
    return base.tostring(v)
  end

  -- Handle tables
  if vtype=='table' then
    local rval = {}
    -- Consider arrays separately
    local bArray, maxCount = isArray(v)
    if bArray then
      for i = 1,maxCount do
        table.insert(rval, encode(v[i]))
      end
    else    -- An object, not an array
      for i,j in base.pairs(v) do
        if isEncodable(i) and isEncodable(j) then
          table.insert(rval, '"' .. encodeString(i) .. '":' .. encode(j))
        end
      end
    end
    if bArray then
      return '[' .. table.concat(rval,',') ..']'
    else
      return '{' .. table.concat(rval,',') .. '}'
    end
  end

  -- Handle null values
  if vtype=='function' and v==null then
    return 'null'
  end

  base.assert(false,'encode attempt to encode unsupported type ' .. vtype .. ':' .. base.tostring(v))
end

local function decode(s, startPos)
  startPos = startPos and startPos or 1
  startPos = decode_scanWhitespace(s,startPos)
  base.assert(startPos<=string.len(s), 'Unterminated JSON encoded object found at position in [' .. s .. ']')
  local curChar = string.sub(s,startPos,startPos)
  -- Object
  if curChar=='{' then
    return decode_scanObject(s,startPos)
  end
  -- Array
  if curChar=='[' then
    return decode_scanArray(s,startPos)
  end
  -- Number
  if string.find("+-0123456789.e", curChar, 1, true) then
    return decode_scanNumber(s,startPos)
  end
  -- String
  if curChar==[["]] or curChar==[[']] then
    return decode_scanString(s,startPos)
  end
  if string.sub(s,startPos,startPos+1)=='/*' then
    return decode(s, decode_scanComment(s,startPos))
  end
  -- Otherwise, it must be a constant
  return decode_scanConstant(s,startPos)
end

local function null()
  return null -- so json.null() will also return null ;-)
end


function decode_scanArray(s,startPos)
  local array = {}  -- The return value
  local stringLen = string.len(s)
  base.assert(string.sub(s,startPos,startPos)=='[','decode_scanArray called but array does not start at position ' .. startPos .. ' in string:\n'..s )
  startPos = startPos + 1
  -- Infinite loop for array elements
  repeat
    startPos = decode_scanWhitespace(s,startPos)
    base.assert(startPos<=stringLen,'JSON String ended unexpectedly scanning array.')
    local curChar = string.sub(s,startPos,startPos)
    if (curChar==']') then
      return array, startPos+1
    end
    if (curChar==',') then
      startPos = decode_scanWhitespace(s,startPos+1)
    end
    base.assert(startPos<=stringLen, 'JSON String ended unexpectedly scanning array.')
    object, startPos = decode(s,startPos)
    table.insert(array,object)
  until false
end

function decode_scanComment(s, startPos)
  base.assert( string.sub(s,startPos,startPos+1)=='/*', "decode_scanComment called but comment does not start at position " .. startPos)
  local endPos = string.find(s,'*/',startPos+2)
  base.assert(endPos~=nil, "Unterminated comment in string at " .. startPos)
  return endPos+2
end

function decode_scanConstant(s, startPos)
  local consts = { ["true"] = true, ["false"] = false, ["null"] = nil }
  local constNames = {"true","false","null"}

  for i,k in base.pairs(constNames) do
    --print ("[" .. string.sub(s,startPos, startPos + string.len(k) -1) .."]", k)
    if string.sub(s,startPos, startPos + string.len(k) -1 )==k then
      return consts[k], startPos + string.len(k)
    end
  end
  base.assert(nil, 'Failed to scan constant from string ' .. s .. ' at starting position ' .. startPos)
end

function decode_scanNumber(s,startPos)
  local endPos = startPos+1
  local stringLen = string.len(s)
  local acceptableChars = "+-0123456789.e"
  while (string.find(acceptableChars, string.sub(s,endPos,endPos), 1, true)
    and endPos<=stringLen
    ) do
    endPos = endPos + 1
  end
  local stringValue = 'return ' .. string.sub(s,startPos, endPos-1)
  local stringEval = base.loadstring(stringValue)
  base.assert(stringEval, 'Failed to scan number [ ' .. stringValue .. '] in JSON string at position ' .. startPos .. ' : ' .. endPos)
  return stringEval(), endPos
end

function decode_scanObject(s,startPos)
  local object = {}
  local stringLen = string.len(s)
  local key, value
  base.assert(string.sub(s,startPos,startPos)=='{','decode_scanObject called but object does not start at position ' .. startPos .. ' in string:\n' .. s)
  startPos = startPos + 1
  repeat
    startPos = decode_scanWhitespace(s,startPos)
    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly while scanning object.')
    local curChar = string.sub(s,startPos,startPos)
    if (curChar=='}') then
      return object,startPos+1
    end
    if (curChar==',') then
      startPos = decode_scanWhitespace(s,startPos+1)
    end
    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly scanning object.')
    -- Scan the key
    key, startPos = decode(s,startPos)
    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly searching for value of key ' .. key)
    startPos = decode_scanWhitespace(s,startPos)
    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly searching for value of key ' .. key)
    base.assert(string.sub(s,startPos,startPos)==':','JSON object key-value assignment mal-formed at ' .. startPos)
    startPos = decode_scanWhitespace(s,startPos+1)
    base.assert(startPos<=stringLen, 'JSON string ended unexpectedly searching for value of key ' .. key)
    value, startPos = decode(s,startPos)
    object[key]=value
  until false   -- infinite loop while key-value pairs are found
end

function decode_scanString(s,startPos)
  base.assert(startPos, 'decode_scanString(..) called without start position')
  local startChar = string.sub(s,startPos,startPos)
  base.assert(startChar==[[']] or startChar==[["]],'decode_scanString called for a non-string')
  local escaped = false
  local endPos = startPos + 1
  local bEnded = false
  local stringLen = string.len(s)
  repeat
    local curChar = string.sub(s,endPos,endPos)
    -- Character escaping is only used to escape the string delimiters
    if not escaped then
      if curChar==[[\]] then
        escaped = true
      else
        bEnded = curChar==startChar
      end
    else
      -- If we're escaped, we accept the current character come what may
      escaped = false
    end
    endPos = endPos + 1
    base.assert(endPos <= stringLen+1, "String decoding failed: unterminated string at position " .. endPos)
  until bEnded
  local stringValue = 'return ' .. string.sub(s, startPos, endPos-1)
  local stringEval = base.loadstring(stringValue)
  base.assert(stringEval, 'Failed to load string [ ' .. stringValue .. '] in JSON4Lua.decode_scanString at position ' .. startPos .. ' : ' .. endPos)
  return stringEval(), endPos
end

function decode_scanWhitespace(s,startPos)
  local whitespace=" \n\r\t"
  local stringLen = string.len(s)
  while ( string.find(whitespace, string.sub(s,startPos,startPos), 1, true)  and startPos <= stringLen) do
    startPos = startPos + 1
  end
  return startPos
end

function encodeString(s)
  s = string.gsub(s,'\\','\\\\')
  s = string.gsub(s,'"','\\"')
  s = string.gsub(s,'\n','\\n')
  s = string.gsub(s,'\t','\\t')
  return s
end

function isArray(t)
  -- Next we count all the elements, ensuring that any non-indexed elements are not-encodable
  -- (with the possible exception of 'n')
  local maxIndex = 0
  for k,v in base.pairs(t) do
    if (base.type(k)=='number' and math.floor(k)==k and 1<=k) then  -- k,v is an indexed pair
      if (not isEncodable(v)) then return false end -- All array elements must be encodable
      maxIndex = math.max(maxIndex,k)
    else
      if (k=='n') then
        if v ~= table.getn(t) then return false end  -- False if n does not hold the number of elements
      else -- Else of (k=='n')
        if isEncodable(v) then return false end
      end  -- End of (k~='n')
    end -- End of k,v not an indexed pair
  end  -- End of loop across all pairs
  return true, maxIndex
end

function isEncodable(o)
  local t = base.type(o)
  return (t=='string' or t=='boolean' or t=='number' or t=='nil' or t=='table') or (t=='function' and o==null)
end




-- Gist Client
-- 2013 Matti Vapa
-- License: MIT

local url = "https://api.github.com/gists"

-- default parameters for POST
local putvars = {}
putvars["description"] = ""
putvars["public"] = true
putvars["files"] = {}


local printUsage = function()
    print("Usage:")
    print("gist get <id>")
    print("gist put <filename1> <filename2> ...")
end

local args = {...}
local mode

if not http then
    print( "gist requires http API" )
    print( "Set enableAPI_http to 1 in mod_ComputerCraft.cfg" )
    return
end

if #args == 2 and args[1] == "get" then
    mode = "get"
elseif args[1] == "put" and #args >= 2 then
    mode = "put"
else
    printUsage()
    return
end

if mode == "get" then

    local id = args[2]

    local resp = http.get(url.."/"..id)

    if resp ~= nil then
        --print("Success with code "..tostring(resp.getResponseCode()).."!")
        local sresp = resp.readAll()
        resp.close()
        local data = decode(sresp)
        --iterate over the files (there can be several in one gist)
        for key, value in pairs(data["files"]) do
            local file = value["filename"]
            local localFile = file
            local path = shell.resolve(localFile)
            local confirm = true
            while fs.exists(path) do
                term.write("Local file "..localFile.." already exists. Overwrite? [y/n] ")
                local inp = io.read():lower()
                if inp ~= "y" then
                    term.write("Download to a new local file? [y/n] ")
                    local inp = io.read():lower()
                    if inp ~= "y" then
                        print("Skipping remote file: "..file)
                        confirm = false
                        break
                    else
                        term.write("Give a new file name: ")
                        localFile = io.read()
                        path = shell.resolve(localFile)
                    end
                else
                    print("Overwriting local file: "..localFile)
                    break
                end
            end
            if confirm then
                local raw = http.get(value["raw_url"])
                if raw == nil then print("Unable to download contents of "..file.."!") return end
                local f = fs.open(path,"w")
                f.write(raw.readAll())
                f.close()
                raw.close()
                print("Remote file "..file.." downloaded!")
            end
        end

    else
        print("Failed to download gist with id "..id.."!")
        return
    end

elseif mode == "put" then
    local files = {}
    for i = 2,#args do
        local file = args[i]
        local path = shell.resolve(file)
        if not fs.exists(path) then
            print("No such file: "..file)
            return
        end
        local f = fs.open(path,"r")
        files[file] = {}
        files[file]["content"] = f.readAll()
        f.close()
    end

    putvars["files"] = files

    print("Give a description for the gist. (Can be blank)")
    putvars["description"] = io.read()

    term.write("Uploading to gist... ")
    local resp = http.post(url,encode(putvars))

    if resp ~= nil then
        print("Success!")
        --print("Success with code "..tostring(resp.getResponseCode()).."!")
        local data = decode(resp.readAll())
        resp.close()
        print("Gist id: "..tostring(data["id"])..".")
        print("Available for viewing at https://gist.github.com/"..tostring(data["id"]))
    else
        print("Failed.")
    end
end