TermPlus

--[[
    Project info:

    Name: TermPlus API
    Creator: Jesusthekiller
    Language: Lua (CC)
    Website: None
    License: GNU GPL
        License file can be fount at www.jesusthekiller.com/license-gpl.html

    Version: 1.0
]]--

--[[
    Changelog:
      1.0:
        Public Release
]]--

--[[
    LICENSE:

    TermPlus API - Terminal Extended!
    Copyright (c) 2013 Jesusthekiller

    This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

    See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>.
]]--

-- Term backup
local oldTerm = {}
for k,v in pairs(term) do
    oldTerm[k] = v
end

-- Overrides table
local overrides = {}

-- Colors API
colors.isValid = function(color)
    color = tonumber(color) or error("Expected number", 2)
    return (color > 0 and color < 65535) and true or false
end

colors.isSingle = function(color)
    for _,v in pairs(colors) do
        if color == v and type(v) == "number" then
            return true
        end
    end
    return false
end

colours.isValid = colors.isValid
colours.isSingle = colors.isSingle

-- Term API - setColor override
local color = {}
color.txt = colors.white  -- Initialize
color.bkg = colors.black

overrides.setTextColor = function(c)
    if colors.isSingle(c) then
        color.txt = c
        oldTerm.setTextColor(c)
    else
        error("Color code expected!", 2)
    end
end
overrides.setTextColour = overrides.setTextColor

overrides.setBackgroundColor = function(c)
    if colors.isSingle(c) then
        color.txt = c
        oldTerm.setBackgroundColor(c)
    else
        error("Color code expected!", 2)
    end
end
overrides.setBackgroundColour = overrides.setBackgroundColor

-- Term API - getColor
overrides.getTextColor = function()
    return color.txt
end
overrides.getTextColour = overrides.getTextColor

overrides.getBackgroundColor = function()
    return color.bkg
end
overrides.getBackgroundColour = overrides.getBackgroundColor

-- Buffer
local buffer = {}
buffer.buffer = {}

buffer.reset = function()
    local maxx, maxy = term.getSize()
    buffer.buffer = {}

    for i = 1, maxy do
        buffer.buffer[i] = {}
    end
end

buffer.clear = function(txt, bkg)
    txt = txt or overrides.getTextColor()
    bkg = bkg or overrides.getBackgroundColor()

    local maxx, maxy = term.getSize()

    for i = 1, maxy do -- Set X
        buffer.buffer[i] = {}
        for j = 1, maxx do -- Set Y
            buffer.buffer[i][j] = {
                ['char'] = " ",
                ['txt'] = txt,
                ['bkg'] = bkg,
            }
        end
    end
end

buffer.clearLine = function(y, txt, bkg)
    y = y or ({term.getCursorPos()})[2]
    txt = txt or overrides.getTextColor()
    bkg = bkg or overrides.getBackgroundColor()

    local maxx, maxy = term.getSize()

    for x = 1, maxx do -- Clear Line
        buffer.buffer[y][x] = {
            ['char'] = " ",
            ['txt'] = txt,
            ['bkg'] = bkg,
        }
    end
end

buffer.setPixel = function(char, x, y, txt, bkg)
    char = char or error("Character expected", 2)
    x = x or term.getCursorPos()
    y = y or ({term.getCursorPos()})[2]
    txt = txt or overrides.getTextColor()
    bkg = bkg or overrides.getBackgroundColor()

    buffer.buffer[y][x] = {
        ['char'] = char,
        ['txt'] = txt,
        ['bkg'] = bkg
    }
end

buffer.scroll = function(lines)
    local maxx, maxy = term.getSize()
    local lines = lines or error("Number expected", 2)

    -- Move up
    for y = 1, maxy - lines do
        buffer.buffer[y] = buffer.buffer[y+lines]
    end

    -- Reset last lines
    for y = maxy - lines, maxy do
        buffer.clearLine(y)
    end
end

-- Term API - overrides
overrides.write = function(text)
    local maxx, maxy = term.getSize()
    text = tostring(text) or ""

    for i = 1, #text do -- Loop trough all chars, print them and store
        local char = text:sub(i,i)
        local x, y = term.getCursorPos()

        if x > 0 and x <= maxx and y > 0 and y <= maxy then
            buffer.setPixel(char, x, y)
            oldTerm.write(char)
        end
    end
end

overrides.clear = function()
    buffer.clear()
    oldTerm.clear()
end

overrides.clearLine = function()
    buffer.clearLine()
    oldTerm.clearLine()
end

overrides.scroll = function(lines)
    lines = lines or error("No lines count specified!", 2)
    buffer.scroll(lines)
    oldTerm.scroll(lines)
end

-- Term API - getPixel/frame
overrides.getPixel = function(x, y)
    x = x or error("No X axis specified!", 2)
    y = y or error("No Y axis specified!", 2)

    return buffer.buffer[y][x]['char'], buffer.buffer[y][x]['txt'], buffer.buffer[y][x]['bkg']
end

-- Restore function
overrides.unloadPlusAPI = function()
    for k,_ in pairs(overrides) do
        term[k] = nil
    end

    for k,v in pairs(oldTerm) do
        term[k] = v
    end

    colors.isValid = nil
    colors.isSingle = nil
end

-- Initialize Buffer
buffer.reset()

-- Replace term functions
for k,v in pairs(overrides) do
    term[k] = v
end