move

--[[
***********
 * prototype::move
 *
 * This is a prototype file for turtle's moving.
 *
 * generally, call this by dofile()
 * and use it in a basic object-based coding of lua.
 *
**********
]]



----------
-- a frame of the prototype
----------
Move = {}


----------
-- constructer
----------
function Move.new()
    -- need modem.
    local rightP = peripheral.getType('right')
    local rightL = peripheral.getType('left')
    if rightP ~= 'modem' and rightL ~= 'modem' then
        return false, 'need modem.'
    end

    -- create coordinates.
    local cords = {}
    cords[1] = 0    -- x
    cords[2] = 0    -- y
    cords[3] = 0    -- z
    cords[4] = 0    -- direction. 0 is +z (south). clock. 1 is -x.

    -- create obj.
    local obj = {cords = cords, initialPos = cords}
    -- set metatable.
    local new = setmetatable(obj, {__index = Move})
    -- get current position.
    local flag, opt = new:currentPos()

    --GPS error.
    if flag == false then
        return false, opt
    end

    -- create position file if it doesn't exist.
    if fs.exists("initialPos") == false then
        local h = fs.open("initialPos", "w")
        h.writeLine("initialPos = {"..new.cords[1]..","..new.cords[2]..","..new.cords[3]..","..new.cords[4].."}")
        h.flush()
        h.close()
    end

    -- set initial position.
    dofile("initialPos")
    new.initialPos = initialPos

    return new
end


----------
-- method for getting the current turtle's position.
-- this uses GPS system. So, it returns false and error rmessage in non-GPS environment.
----------
function Move:currentPos()
    --get first position.
    local pos1 = {gps.locate(30)}
    if pos1 == nil then
        return false, "Can't connect to GPS, and failed to get pos1 in Move:currentPos()."
    end

    --try to move to get second position.
    local flag1 = true
    for i=1, 4, 1 do
        if turtle.detect() == false then
            flag1 = false
            break
        end
        turtle.turnLeft()
    end
    local flag, msg = self:moveSure()
    if flag == false then
        return false, "Can't move, and failed to get pos2 in Move:currentPos()."
    end

    --get second position.
    local pos2 = {gps.locate(30)}
    if pos2 == nil then
        return false, "Can't connect to GPS, and failed to get pos2 in Move:currentPos()."
    end

    --confirm direction and set cords.
    local distX = pos2[1] - pos1[1]
    local distZ = pos2[3] - pos1[3]
    if distX == 1 then
        self.cords[4] = 3
    elseif distX == -1 then
        self.cords[4] = 1
    elseif distZ == 1 then
        self.cords[4] = 0
    elseif distZ == -1 then
        self.cords[4] = 2
    end
    self.cords[1] = pos2[1]
    self.cords[2] = pos2[2]
    self.cords[3] = pos2[3]

    -- return to first pos.
    self:turnLeft()
    self:turnLeft()
    local flag, msg = self:moveSure()
    if flag == false then
        return false, "Can't move, and failed to return to  pos1 in Move:currentPos()."
    end
    self:turnLeft()
    self:turnLeft()

    return true
end

----------
-- methods for moving.
----------
function Move:turnLeft()
    self.cords[4] = (self.cords[4] - 1) % 4

    if turtle.turnLeft() == false then
        self.cords[4] = (self.cords[4] + 1) % 4
        return false
    end
--  self:dispCords()
    return true
end


function Move:turnRight()
    self.cords[4] = (self.cords[4] + 1) % 4

    if turtle.turnRight() == false then
        self.cords[4] = (self.cords[4] - 1) % 4
        return false
    end
--  self:dispCords()
    return true
end


function Move:forward()
    local sign, way = self:getFacingDir()

    self.cords[way] = self.cords[way] + sign
    if turtle.forward() == false then
        self.cords[way] = self.cords[way] - sign
        return false
    end
--  self:dispCords()
    return true
end


function Move:back()
    local sign, way = self:getFacingDir()

    self.cords[way] = self.cords[way] - sign
    if turtle.back() == false then
        self.cords[way] = self.cords[way] + sign
        return false
    end
--  self:dispCords()
    return true
end


function Move:up()
    self.cords[2] = (self.cords[2] + 1)

    if turtle.up() == false then
        self.cords[2] = (self.cords[2] - 1)
        return false
    end
--  self:dispCords()
    return true
end


function Move:down()
    self.cords[2] = (self.cords[2] - 1)

    if turtle.down() == false then
        self.cords[2] = (self.cords[2] + 1)
        return false
    end
--  self:dispCords()
    return true
end

----------
-- method for safe moving.
----------
-- remove mob, and move.
function Move:moveSafe(dir)
    local moveFunc = self.forward
    local attackFunc = turtle.attack

    if dir == 'up' then
        moveFunc = self.up
        attackFunc = turtle.attackUp
    elseif dir == 'down' then
        moveFunc = self.down
        attackFunc = turtle.attackDown
    end

    local times = 0
    while moveFunc(self) == false do
        attackFunc()
        times = times + 1
        if times == 20 then
            return false, "moving obstructed by unkown."
        end
    end

    return true
end

-- remove mob and block, and move.
function Move:moveSure(dir)
    local moveFunc = self.forward
    local detectFunc = turtle.detect
    local digFunc = turtle.dig
    local attackFunc = turtle.attack

    if dir == 'up' then
        moveFunc = self.up
        detectFunc = turtle.detectUp
        digFunc = turtle.digUp
        attackFunc = turtle.attackUp
    elseif dir == 'down' then
        moveFunc = self.down
        detectFunc = turtle.detectDown
        digFunc = turtle.digDown
        attackFunc = turtle.attackDown
    end

    local times = 0
    while detectFunc() do
        digFunc()
        times = times + 1
        if times == 20 then
            return false, "moving obstructed by block."
        end
        sleep(1)
    end
    times = 0
    while moveFunc(self) == false do
        attackFunc()
        times = times + 1
        if times == 20 then
            return false, "moving obstructed by unkown."
        end
    end

    return true
end

----------
-- method for getting direction.
----------
function Move:getFacingDir()
    local sign = 1
    if self.cords[4] %3 ~= 0 then
        sign = -1
    end

    local way = 1
    if self.cords[4] % 2 == 0 then
        way = 3
    end

    return sign, way
end

----------
-- method for rotation.
----------
function Move:rotate(direction)
    if (self.cords[4] - direction) ~= 1 then
        while self.cords[4] ~= direction do
            self:turnRight()
        end
    else
        while self.cords[4] ~= direction do
            self:turnLeft()
        end
    end
end

----------
-- method for display cords.
----------
function Move:dispCords()
    print(self.cords[1]..","..self.cords[2]..","..self.cords[3]..","..self.cords[4])
end

----------
-- method for getting distances.
----------
function Move:getDistances(x, y, z)
    local distX = self.cords[1] - x
    local distY = self.cords[2] - y
    local distZ = self.cords[3] - z
    return distX, distY, distZ
end

----------
-- methods for going Straight.
----------
-- if plus, do 1. if minus, do 3.
function Move:goStraightX(distX)
    if self:isPlus(distX) then
        self:rotate(1)
    else
        self:rotate(3)
    end
    for i=1, math.abs(distX), 1 do
        self:moveSafe()
    end
end

-- if plus, down. if minus, up.
function Move:goStraightY(distY)
    if self:isPlus(distY) then
        for i=1, math.abs(distY), 1 do
            self:moveSafe("down")
        end
    else
        for i=1, math.abs(distY), 1 do
            self:moveSafe("up")
        end
    end
end

-- if puls, go 2. if minus, go 0.
function Move:goStraightZ(distZ)
    if self:isPlus(distZ) then
        self:rotate(2)
    else
        self:rotate(0)
    end
    for i=1, math.abs(distZ), 1 do
        self:moveSafe()
    end
end

----------
-- method for return to initial point.
----------
function Move:returnToIniPointSure()
    local distX, distY, distZ = self:getDistances(self.initialPos[1], self.initialPos[2], self.initialPos[3])

    -- resolve Y.
    if self:isPlus(distY) then
        for i=1, math.abs(distY), 1 do
            self:moveSure('down')
        end
    else
        for i=1, math.abs(distY), 1 do
            self:moveSure('up')
        end
    end
    -- resolve X.
    if self:isPlus(distX) then
        self:rotate(1)
    else
        self:rotate(3)
    end
    for i=1, math.abs(distX), 1 do
        self:moveSure()
    end
    -- resolve Z.
    if self:isPlus(distZ) then
        self:rotate(2)
    else
        self:rotate(0)
    end
    for i=1, math.abs(distZ), 1 do
        self:moveSure()
    end
    --resolve dir.
    self:rotate(self.initialPos[4])
end

function Move:isPlus(num)
    if num/math.abs(num) == 1 then
        return true
    else
        return false
    end
end


--[[
**********
 * end of the file
**********
]]