#!/usr/bin/python
# generate a map

# map will be bottom-left (0,0) - 256 x 256 in dimensions.
# player will be at (32,32) due north
# sector 0 will be the only sector with light level 120, floor 0,
# ceiling 128, no specials
# floor will be floor0_1
# sky will be f_sky1
# linedefs will all have a mid-texture STARTAN2

# things first: each int is 2 bytes le; 
from struct import pack, unpack
import sys
x = y = 32
angle = 0
doomed = 0x01 # player start
flags = 0x0001 | 0x0002 | 0x0004
THINGS = pack("<5h", x, y, angle, doomed, flags)

# vertices next: we'll go clockwise from the start point
vertices = [ (0,0), (0,128), (0,256), (256,256), (256,128), (256,0) ]
VERTEXES = ''.join(
    map(''.join,
        map(lambda tuple: map(lambda x: pack("<h", x), tuple), vertices)
    )
)

# sectors
# a 32 bit int it seems
floor = 0
ceil = 128
ftex = "FLOOR0_1"
ctex = "F_SKY1\0\0"
light = 120
type = 0
tag = 0
sector = pack("<hh8s8shhh", floor,ceil,ftex,ctex,light,type,tag)
SECTORS = sector * 2

# sidedefs
# x off / y off / upper / lower / middle / sector number
blank = "-%s" % (7 * '\0')
tex = "STARTAN2"
xoff = yoff = 0
#sidedefs = pack("<hh8s8s8sh", xoff, yoff, blank, blank, tex, sector)

sidedefs = [
    (0, 0, blank, blank, tex, 0),
    (0, 0, blank, blank, tex, 1),
    (0, 0, blank, blank, tex, 1),
    (0, 0, blank, blank, tex, 1),
    (0, 0, blank, blank, tex, 0),
    (0, 0, blank, blank, tex, 0),
    (0, 0, blank, blank, tex, 0),
    (0, 0, blank, blank, tex, 1)
]


# first pass: concatenate all the lists
SIDEDEFS = []
for list in sidedefs:
    SIDEDEFS += list
# second pass: run pack on it all
SIDEDEFS = map(lambda x: pack("<hh8s8s8sh", x), SIDEDEFS)
# third pass: concatenate the result
tmp = ''
for bit in SIDEDEFS:
    tmp += bit
SIDEDEFS = tmp


# linedefs now
# 14 bytes long (7 x shorts)
# start v / end v / flags /  special / tag / r side / l side
# what value is used for a non-existent sidedef? -1
# flags 1 = blocks
linedefs = [
    (0, 1, 1, 0, 0, 0, -1),
    (1, 2, 1, 0, 0, 1, -1),
    (2, 3, 1, 0, 0, 2, -1),
    (3, 4, 1, 0, 0, 3, -1),
    (4, 5, 1, 0, 0, 4, -1),
    (5, 0, 1, 0, 0, 5, -1),
    (1, 4, 1, 0, 0, 6, 7)
]
# first pass: concatenate all the lists
LINEDEFS = []
for list in linedefs:
    LINEDEFS += list
# second pass: run pack on it all
LINEDEFS = map(lambda x: pack("<h", x), LINEDEFS)
# third pass: concatenate the result
tmp = ''
for bit in LINEDEFS:
    tmp += bit
LINEDEFS = tmp

# build the directory
hoffs = 12 # header length offset
MAP01 = ''
lumps = {
    "MAP01\0\0\0":MAP01,
    "THINGS\0\0": THINGS,
    "VERTEXES":   VERTEXES,
    "LINEDEFS":   LINEDEFS,
    "SIDEDEFS":   SIDEDEFS,
    "SECTORS\0":  SECTORS
}
order = [
    "MAP01\0\0\0",
    "THINGS\0\0",
    "VERTEXES",
    "LINEDEFS",
    "SIDEDEFS",
    "SECTORS\0"
]

filepos = hoffs
dir = ''
for k in order:
    v = lumps[k]
    size = len(v)
    ent = pack("<ll8s", filepos, size, k)
    dir += ent
    filepos += size

# now the data
data = MAP01 + THINGS + VERTEXES + LINEDEFS + SIDEDEFS + SECTORS

# now the header

header = pack("<4sll", "PWAD", len(lumps.values()), len(data) + hoffs)

# now write it all out
sys.stdout.write(header)
sys.stdout.write(data)
sys.stdout.write(dir)