/*
          Title:  Geography
      Credit to:  Deadron
    Modified by:  CaptFalcon33035
 Contributed by:  CaptFalcon33035
     Based from:  Dearon.Geography
     
 I was just looking over this library trying to determine what
 libraries were required to run Deadron's Quest library and I
 realized that much of the workings of this library could be 
 improved to a great deal.  So here it is!
*/

#define isturf(n) istype(n, /turf)

atom/proc/dd_area()
    if(istype(src, /area)) return src
    var/turf/my_loc = locate(src.x, src.y, src.z)
    return (my_loc)?(my_loc.loc):(null)


proc/dd_direction_name(var/direction)
    . = ""
    if(direction & NORTH)      . += "NORTH"
    else if(direction & SOUTH) . += "SOUTH"
    if(direction & EAST)       . += "EAST"
    else if(direction & WEST)  . += "WEST"

proc/dd_get_dist(var/first, var/second)
    // Right triangle rule: A squared + B squared = C squared.
    var/x = abs(first:x - second:x)
    var/y = abs(first:y - second:y)
    return round(sqrt((x * x) + (y * y)))

// proc/dd_get_step(var/atom/O, var/direction)
proc/get_steps(var/atom/ref, var/dir, var/dist=1)
    if(!ref || !dir || !ref.loc) return 0
    var/x_add = 0
    var/y_add = 0
    if(ref.dir & NORTH)      y_add = dist
    else if(ref.dir & SOUTH) y_add = -dist
    if(ref.dir & EAST)       x_add = dist
    else if(ref.dir & WEST)  x_add = -dist
    return locate(ref.x+x_add, ref.y+y_add, ref.z)

proc/dd_get_step_rand(var/atom/O, var/randomness=10, var/considerDensity=1)
    ASSERT(istype(O))
    var/turf/newLoc
    var/direction
    var/isTurf = isturf(O)

    // Behave random or predictable this time?
    if(isTurf || prob(randomness))
        // Turfs are always random.
        direction = randomDirection()
        newLoc = get_steps(O, direction)
        if(newLoc && (isTurf || !considerDensity || newLoc.Enter(O)))
            return newLoc
    else
        // Not random; just move in same direction if possible.
        direction = O.dir
        newLoc = get_steps(O, direction)
        if(newLoc && (!considerDensity || newLoc.Enter(O))) return newLoc

    // Rotate through every turf in oview() until one is validated.
    var/list/my_oview = oview(O, 1)
    for(var/turf/t in my_oview) 
        if(isTurf || !considerDensity || t.Enter(O)) return t
    return null

proc/dd_reverse_direction(var/direction)
    . = turn(direction, 180)

proc/dd_step_rand(var/atom/movable/M, var/randomness=10)
    ASSERT(istype(M))
    var/considerDensity=1
    var/turf/newLoc = dd_get_step_rand(M, randomness, considerDensity)
    if(newLoc) return M.Move(newLoc)
    return null
    
proc/randomDirection()
    . = pick(NORTH, SOUTH, EAST, WEST, NORTHEAST,\
        NORTHWEST, SOUTHEAST, SOUTHWEST)