-- load json module
JSON = assert(loadfile "scriptbank\\custom\\json.lua")()

-- internal database table
tbl_database={}

-- public function table
Database={}
function Database.Create(ID) -- creates a database
	tbl_database[ID]={}
end
function Database.AddRow(ID, tbl_data) -- adds a row to the database
	table.insert(tbl_database[ID], tbl_data)
end
function Database.CountRows(ID) -- counts database rows
	return #tbl_database[ID]
end
function Database.GetRow(ID, row) -- get a database row data
	return tbl_database[ID][row]
end
function Database.RemoveRow(ID, row) -- removes a database row
	table.remove(tbl_database[ID],row)
end
function Database.Clear(ID) -- clear a database
	tbl_database[ID]=nil
end


function Database.Save(ID, filename)
	local file = io.open (filename , "w+")
	local json_text = JSON:encode(tbl_database[ID])
	file:write(json_text)
	file:close()
end
function Database.Load(ID, filename)
	local tbl_return={}
	local file = io.open (filename , "r")
	if file then
		tbl_database[ID] = JSON:decode(file:read("*a"), "bla")
		file:close()
	end
end


-- Example code
tmpVar_LoadOrCreate="create" -- set to "anything" to disable creation code and load saved database
function database_init(e)
	
	if tmpVar_LoadOrCreate == "create" then
		-- firse we define the database
		Database.Create("testDB")
		
		-- now we add some data
		tbl_data={} -- define the data table
		-- index the table item by column name "column1/2/3/4"
		tbl_data["column1"]="row 1 - item 1" -- add column 1 data
		tbl_data["column2"]="row 1 - item 2" -- add column 1 data
		tbl_data["column3"]="row 1 - item 3" -- add column 1 data
		tbl_data["column4"]="row 1 - item 4" -- add column 1 data
		-- now add the above table to the db table
		Database.AddRow("testDB", tbl_data)
		
		-- add a couple more items
		tbl_data={}
		tbl_data["column1"]="row 2 - item 1"
		tbl_data["column2"]="row 2 - item 2"
		tbl_data["column3"]="row 2 - item 3"
		tbl_data["column4"]="row 2 - item 4"
		Database.AddRow("testDB", tbl_data)
		
		tbl_data={}
		tbl_data["column1"]="row 3 - item 1"
		tbl_data["column2"]="row 3 - item 2"
		tbl_data["column3"]="row 3 - item 3"
		tbl_data["column4"]="row 3 - item 4"
		Database.AddRow("testDB", tbl_data)
		
		Database.Save("C:\\Users\\Main\\AppData\\Local\\luadatabase.dat")
	else
		-- set tmpVar_LoadOrCreate="anything" to enable loading from disk
		Database.Load("testDB", "C:\\Users\\Main\\AppData\\Local\\luadatabase.dat")
		Database.RemoveRow("testDB", 1)
	end
end
function database_main(e)
		
	-- count the rows added to the database
	rows=Database.CountRows("testDB")
	-- display row count
	Text(1, 1, 1, "Contains " ..rows.. " rows")
	
	-- get data for row 1
	local t_data = Database.GetRow("testDB",1)
	-- display data
	Text(1, 5, 1, "Column 1="..t_data["column1"])
	Text(1, 9, 1, "Column 2="..t_data["column2"])
	Text(1, 14, 1, "Column 3="..t_data["column3"])
	Text(1, 18, 1, "Column 4="..t_data["column4"])
	
	-- display all data
	for i=1, rows do
		-- get data for row 1
		local t_data = Database.GetRow("testDB",i)
		-- display data
		str="Column 1="..t_data["column1"]
		str=str.."Column 2="..t_data["column2"]
		str=str.."Column 3="..t_data["column3"]
		str=str.."Column 4="..t_data["column4"]
		
		Text(20, i*5, 1, str)
	end
	
end

function database_exit(e)
	Database.Save("testDB", "C:\\Users\\Main\\AppData\\Local\\luadatabase.dat")
end