PocketShell Installer

--The majority of this code is oeed's install script, so thanks to him for this

if not term.isColor or not term.isColor() then
        error('PocketShell requires an advanced PDA')
end

_jstr = [[
        local base = _G

        -----------------------------------------------------------------------------
        -- Module declaration
        -----------------------------------------------------------------------------

        -- Public functions

        -- Private functions
        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

        -----------------------------------------------------------------------------
        -- PUBLIC FUNCTIONS
        -----------------------------------------------------------------------------
        --- Encodes an arbitrary Lua object / variable.
        -- @param v The Lua object / variable to be JSON encoded.
        -- @return String containing the JSON encoding in internal Lua string format (i.e. not unicode)
        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


        --- Decodes a JSON string and returns the decoded value as a Lua data structure / value.
        -- @param s The string to scan.
        -- @param [startPos] Optional starting position where the JSON string is located. Defaults to 1.
        -- @param Lua object, number The object that was scanned, as a Lua table / string / number / boolean or nil,
        -- and the position of the first character after
        -- the scanned JSON object.
        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

        --- The null function allows one to specify a null value in an associative array (which is otherwise
        -- discarded if you set the value with 'nil' in Lua. Simply set t = { first=json.null }
        function null()
          return null -- so json.null() will also return null ;-)
        end
        -----------------------------------------------------------------------------
        -- Internal, PRIVATE functions.
        -- Following a Python-like convention, I have prefixed all these 'PRIVATE'
        -- functions with an underscore.
        -----------------------------------------------------------------------------

        --- Scans an array from JSON into a Lua object
        -- startPos begins at the start of the array.
        -- Returns the array and the next starting position
        -- @param s The string being scanned.
        -- @param startPos The starting position for the scan.
        -- @return table, int The scanned array as a table, and the position of the next character to scan.
        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

        --- Scans a comment and discards the comment.
        -- Returns the position of the next character following the comment.
        -- @param string s The JSON string to scan.
        -- @param int startPos The starting position of the comment
        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

        --- Scans for given constants: true, false or null
        -- Returns the appropriate Lua type, and the position of the next character to read.
        -- @param s The string being scanned.
        -- @param startPos The position in the string at which to start scanning.
        -- @return object, int The object (true, false or nil) and the position at which the next character should be
        -- scanned.
        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

        --- Scans a number from the JSON encoded string.
        -- (in fact, also is able to scan numeric +- eqns, which is not
        -- in the JSON spec.)
        -- Returns the number, and the position of the next character
        -- after the number.
        -- @param s The string being scanned.
        -- @param startPos The position at which to start scanning.
        -- @return number, int The extracted number and the position of the next character to scan.
        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

        --- Scans a JSON object into a Lua object.
        -- startPos begins at the start of the object.
        -- Returns the object and the next starting position.
        -- @param s The string being scanned.
        -- @param startPos The starting position of the scan.
        -- @return table, int The scanned object as a table and the position of the next character to scan.
        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

        --- Scans a JSON string from the opening inverted comma or single quote to the
        -- end of the string.
        -- Returns the string extracted as a Lua string,
        -- and the position of the next non-string character
        -- (after the closing inverted comma or single quote).
        -- @param s The string being scanned.
        -- @param startPos The starting position of the scan.
        -- @return string, int The extracted string as a Lua string, and the next character to parse.
        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

        --- Scans a JSON string skipping all whitespace from the current start position.
        -- Returns the position of the first non-whitespace character, or nil if the whole end of string is reached.
        -- @param s The string being scanned
        -- @param startPos The starting position where we should begin removing whitespace.
        -- @return int The first position where non-whitespace was encountered, or string.len(s)+1 if the end of string
        -- was reached.
        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

        --- Encodes a string to be JSON-compatible.
        -- This just involves back-quoting inverted commas, back-quotes and newlines, I think ;-)
        -- @param s The string to return as a JSON encoded (i.e. backquoted string)
        -- @return The string appropriately escaped.
        function encodeString(s)
          s = string.gsub(s,'\\','\\\\')
          s = string.gsub(s,'"','\\"')
          s = string.gsub(s,"'","\\'")
          s = string.gsub(s,'\n','\\n')
          s = string.gsub(s,'\t','\\t')
          return s
        end

        -- Determines whether the given Lua type is an array or a table / dictionary.
        -- We consider any table an array if it has indexes 1..n for its n items, and no
        -- other data in the table.
        -- I think this method is currently a little 'flaky', but can't think of a good way around it yet...
        -- @param t The table to evaluate as an array
        -- @return boolean, number True if the table can be represented as an array, false otherwise. If true,
        -- the second returned value is the maximum
        -- number of indexed elements in the array.
        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

        --- Determines whether the given Lua object / table / variable can be JSON encoded. The only
        -- types that are JSON encodable are: string, boolean, number, nil, table and json.null.
        -- In this implementation, all other types are ignored.
        -- @param o The object to examine.
        -- @return boolean True if the object should be JSON encoded, false if it should be ignored.
        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
]]

function loadJSON()
        local sName = 'JSON'

        local tEnv = {}
        setmetatable( tEnv, { __index = _G } )
        local fnAPI, err = loadstring(_jstr)
        if fnAPI then
                setfenv( fnAPI, tEnv )
                fnAPI()
        else
                printError( err )
                return false
        end

        local tAPI = {}
        for k,v in pairs( tEnv ) do
                tAPI[k] =  v
        end

        _G[sName] = tAPI
        return true
end

print('PocketShell Installer')
print('Please wait...')

Settings = {
        InstallPath = '/', --Where the program's installed, don't always asume root
        Hidden = false, --Whether or not the update is hidden (doesn't write to the screen), useful for background updates
        GitHubUsername = 'ROFLCopter64bit', --Your GitHub username as it appears in the URL
        GitHubRepoName = 'PocketShell', --The repo name as it appears in the URL
        DownloadReleases = true, --If true it will download the latest release, otherwise it will download the files as they currently appear
        UpdateFunction = nil, --Sent when something happens (file downloaded etc.)
        TotalBytes = 0, --Do not change this value (especially programatically)!
        DownloadedBytes = 0, --Do not change this value (especially programatically)!
        Status = '',
        SecondaryStatus = '',
}

loadJSON()

function downloadJSON(path)
        local _json = http.get(path)
        if not _json then
                error('Could not download, check your connection.')
        end
        return JSON.decode(_json.readAll())
end

if http then
        print('HTTP enabled, attempting update...')
else
        print('HTTP is required to update.')
                sleep(5)
        error('')
end

print('Determining Latest Version')
local releases = downloadJSON('https://api.github.com/repos/'..Settings.GitHubUsername..'/'..Settings.GitHubRepoName..'/releases')
local latestReleaseTag = releases[1].tag_name
print('Obtaining Latest Version URL')
local refs = downloadJSON('https://api.github.com/repos/'..Settings.GitHubUsername..'/'..Settings.GitHubRepoName..'/git/refs')
local latestReleaseSha = ''
for i, v in ipairs(refs) do
        if v.ref == 'refs/tags/'..latestReleaseTag then
                latestReleaseSha = v.object.sha
        end
end

print('Downloading File Listing')

local tree = downloadJSON('https://api.github.com/repos/'..Settings.GitHubUsername..'/'..Settings.GitHubRepoName..'/git/trees/'..latestReleaseSha..'?recursive=1').tree

local blacklist = {
        '/.gitignore',
        '/README.md',
        '/.gitattributes',
    '/version'
}

function isBlacklisted(path)
        for i, item in ipairs(blacklist) do
                if item == path then
                        return true
                end
        end
        return false
end

Settings.TotalFiles = 0
Settings.TotalBytes = 0
for i, v in ipairs(tree) do
        if not isBlacklisted(Settings.InstallPath..v.path) and v.size then
                Settings.TotalBytes = Settings.TotalBytes + v.size
                Settings.TotalFiles = Settings.TotalFiles + 1
        end
end

Settings.DownloadedBytes = 0
function downloadBlob(v)
        if isBlacklisted(Settings.InstallPath..v.path) then
                return
        end
        if v.type == 'tree' then
                print('Making folder: '..'/'..Settings.InstallPath..v.path)
                fs.makeDir('/'..Settings.InstallPath..v.path)
        else
                print('Starting download for: '..Settings.InstallPath..v.path)
                local f = http.get(('https://raw.github.com/'..Settings.GitHubUsername..'/'..Settings.GitHubRepoName..'/'..latestReleaseTag..Settings.InstallPath..v.path):gsub(' ','%%20'))
                if not f then
                        error('Downloading failed, try again. '..('https://raw.github.com/'..Settings.GitHubUsername..'/'..Settings.GitHubRepoName..'/'..latestReleaseTag..Settings.InstallPath..v.path):gsub(' ','%%20'))
                end
                local h = fs.open('/'..Settings.InstallPath..v.path, 'w')
                h.write(f.readAll())
                h.close()
                print('('..math.floor(100*(Settings.DownloadedBytes/Settings.TotalBytes))..'%) Downloaded: '..Settings.InstallPath..v.path)
                if v.size then
                        Settings.DownloadedBytes = Settings.DownloadedBytes + v.size
                end
        end
end

local downloads = {}
for i, v in ipairs(tree) do
        table.insert(downloads, function()downloadBlob(v)end)
end

parallel.waitForAll(unpack(downloads))

local h = fs.open('/system/.version', 'w')
h.write(latestReleaseTag)
h.close()

print('Installation Complete!')
print('Rebooting...')
sleep(1)
os.reboot()