crdb

tmpExt = ".dbtmp"
dbExt = ".crdb"
programData = "/system/data/crdb/dbtmp/"
-- Function by Colandus
local function trim(str)
  return (string.gsub(str, "^%s*(.-)%s*$", "%1"))
end

local function explode(str, sep)
  local pos, t = 1, {}
  if #sep == 0 or #str == 0 then return end
  for s, e in function() return string.find(str, sep, pos) end do
    table.insert(t, trim(string.sub(str, pos, s-1)))
    pos = e+1
  end
  table.insert(t, trim(string.sub(str, pos)))
  return t
end
-- end Colandus function

function ver()
  return 0.1
end

function loadDb(loadDbPath)
  function parseLine(strLine)
    if string.sub(strLine, 1, 2) == "@@" then
      curParsTable = string.sub(strLine, 3)
      tables[tablesCount] = curParsTable
      tablesCount = tablesCount + 1
      fs.makeDir(programData..curParsTable)
    elseif string.sub(strLine, 1, 2) == "##" then
      curParsCol = string.sub(strLine, 3)
      curColWrite = io.open(programData..curParsTable.."/"..curParsCol..tmpExt, "w")
      curColWrite:write("")
    elseif string.sub(strLine, 1, 2) == "*'" then
      curParsLn = string.sub(strLine, 3, (string.len(strLine) - 1))
      curColWrite:write(curParsLn.."\n")
    elseif string.sub(strLine, 1, 2) == "#!" then
      curColWrite:close()
      curParsCol = nil
    elseif string.sub(strLine, 1, 2) == "@!" then
      curParsTable = nil
    end
  end
 if string.find(loadDbPath, "%.") ~= nil then
  loadDbPath = string.sub(loadDbPath, 1,(string.find(loadDbPath, "%.")-1))
  curDb = fs.open(loadDbPath..dbExt, "r")
  tables = {}
  lineDb = {}
  curParsTable = nil
  curParsCol = nil
  local curLine = 1
  tablesCount = 1
  while true do
    loadLine = curDb.readLine()
    if loadLine == nil then
      break
    end
    parseLine(loadLine)
    curLine = curLine + 1
  end
  return true
 else
  return false
 end
end

function listDir(listDirPath)
  listDirArray = {}
  listFileArray = {}
  listDir_i = 1
  listFile_i = 1
  for listEv, listItem in ipairs(fs.list(listDirPath)) do
    if fs.isDir(listDirPath..listItem) then
      listDirArray[listDir_i] = listItem
      listDir_i = listDir_i + 1
    else
      listFileArray[listFile_i] = listItem
      listFile_i = listFile_i + 1
    end
  end
  return listDirArray, listFileArray
end

function closeDb(closeDbPath)
  function closeCompileNWrite()
    closeGetTables = listDir(programData)
    closeTmpToCompile = {}
    closeDbTree = {}
    closeTmpNil = nil
    if table.getn(closeGetTables) ~= 0 and table.getn(closeGetTables) ~= nil then
      for i=1, table.getn(closeGetTables) do
        closeTmpDb.writeLine("@@"..closeGetTables[i])
        closeTmpNil, closeDbCurCols = listDir(programData..closeGetTables[i])
        if table.getn(closeDbCurCols) ~= 0 and table.getn(closeDbCurCols) ~= nil then
          for i2=1, table.getn(closeDbCurCols) do
            closeDbCurCols[i2] = string.sub(closeDbCurCols[i2],1 , string.len(closeDbCurCols[i2]) - string.len(tmpExt))
             closeTmpDb.writeLine("##"..closeDbCurCols[i2])
            closeDbColCurFile = fs.open(programData..closeGetTables[i].."/"..closeDbCurCols[i2]..tmpExt, "r")
            while true do
              closeTmpLoadLn = closeDbColCurFile.readLine()
              if closeTmpLoadLn == nil then
                break
              end
              closeTmpDb.writeLine("*'"..closeTmpLoadLn.."'")
            end
            closeDbColCurFile.close()
            closeTmpDb.writeLine("#!"..closeDbCurCols[i2])
          end
        end
        closeTmpDb.writeLine("@!"..closeGetTables[i])
      end
    end
    return true
  end

  curDb.close()
  fs.delete(closeDbPath..tmpExt)
  closeTmpDb = fs.open(closeDbPath..tmpExt, "w")
  closeTmpDb.write("")
  closeCompileNWrite()
  closeTmpDb.close()
  fs.delete(closeDbPath..dbExt)
  fs.move(closeDbPath..tmpExt, closeDbPath..dbExt)
  fs.delete(programData)
  sleep(0.05)
  fs.makeDir(programData)
end

function queryDb(query)
  if query == nil then
    return false, false
  end
  queryData = explode(query, " | ")
  query = explode(queryData[1], " ")
  queryData = queryData[2]
  local queryCount = 1
  queryResult1 = {}
  queryLoadLn = {}
  queryResultTmp = nil
  queryCurFilePath = nil
  if string.upper(query[1]) == "SELECT" then
    if query[3] == nil then
      query[3] = ""
    end
    if string.upper(query[3]) == "FROM" then
      queryCurFilePath = programData..query[4].."/"..query[2]..tmpExt
      if fs.exists(programData..query[4]) then
        if fs.exists(queryCurFilePath) then
          queryCurFile = fs.open(queryCurFilePath, "r")
          while true do
            queryResultTmp = queryCurFile.readLine()
              if queryResultTmp == nil then
                break
              end
            queryResult1[queryCount] = queryResultTmp
            queryCount = queryCount + 1
          end
          queryCurFile.close()
          return queryResult1
        else
          return {false, "CRDB error: no column "..query[2].." in "..query[4]}
        end
      else
       return {false, "CRDB error: no table "..query[4]}
      end
    elseif query[3] == "" and query[2] ~= nil then
      queryCurFilePath = programData..query[2]
      if fs.exists(queryCurFilePath) then
        tmpSelectResult, queryResult1 = listDir(queryCurFilePath)
        for i=1, table.getn(queryResult1) do
          tmpExplode = explode(queryResult1[i], "%.")
          queryResult1[i] = tmpExplode[1]
        end
        return queryResult1
      else
        return {false, "CRDB error: no table "..query[2]}
      end
    end
  elseif string.upper(query[1]) == "INSERT" and string.upper(query[2]) == "INTO" then
    queryInsertArray = explode(query[3], ">")
    queryCurFilePath = programData..queryInsertArray[1].."/"..queryInsertArray[2]..tmpExt
    if queryData == nil then
      queryData = ""
    end
    if fs.exists(programData..queryInsertArray[1]) then
      if fs.exists(queryCurFilePath) then
        queryCurFile = fs.open(queryCurFilePath, "a")
        queryCurFile.writeLine(queryData)
        queryCurFile.close()
        return {true}
      else
        return {false, "CRDB error: no column "..queryInsertArray[2].." in "..queryInsertArray[1]}
      end
    else
      return {false, "CRDB error: no table "..queryInsertArray[1]}
    end
  elseif string.upper(query[1]) == "DELETE" and string.upper(query[2]) == "FROM" then
    if fs.exists(programData..query[3]) then
      if string.upper(query[4]) == "WHERE" then
        queryDeleteArray = explode(query[5], "=")
        if fs.exists(programData..query[3].."/"..queryDeleteArray[1]..tmpExt) then
          queryCurFile = fs.open(programData..query[3].."/"..queryDeleteArray[1]..tmpExt, "r")
          while true do
            queryLoadLnTmp = queryCurFile.readLine()
            if queryLoadLnTmp == nil then
              break
            end
            if queryLoadLnTmp ~= queryDeleteArray[2] then
              queryLoadLn[queryCount] = queryLoadLnTmp
            end
            queryCount = queryCount + 1
          end
          queryCurFile.close()
          queryCurFile = nil -- unload file
          fs.delete(programData..query[3].."/"..queryDeleteArray[1]..tmpExt)
          queryCurFile = io.open(programData..query[3].."/"..queryDeleteArray[1]..tmpExt, "w")
          queryCurFile:write("")
          for i=1, table.getn(queryLoadLn) do
            queryCurFile:write(queryLoadLn[i].."\n")
          end
          queryCurFile:close()
          return{true}
        else
          return {false, "CRDB error: no column "..queryDeleteArray[1].." in "..query[3], programData..query[3].."/"..queryDeleteArray[1]}
        end
      else
        return {false, "CRDB error: unknown query '"..query[4].."'"}
      end
    else
      return {false, "CRDB error: no table "..query[3]}
    end
  elseif string.upper(query[1]) == "SHOW" and string.upper(query[2]) == "TABLES" then
    queryResult1 = listDir(programData)
    return queryResult1
  else
    return {false, "CRDB error: unknown command"}
  end
end