#!/usr/bin/env python3
#
# Copyright (C) 2020 Herbert Poetzl
#
# 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 2 of the License, or
# (at your option) any later version.
#

import sys
import numpy as np
import itertools as it


RAW_WIDTH = 4096
RAW_HEIGHT = 3072

NUM_REGS = 128

def raw12_reader(path):
    with open(path, 'rb') as f:
        for row in range(RAW_HEIGHT):
            for col in range(RAW_WIDTH >> 1):
                val = f.read(3)
                yield (val[0] << 4) | (val[1] >> 4)
                yield ((val[1] & 0xF) << 8) | val[2]
        for reg in range(NUM_REGS):
            val = f.read(2)
            yield (val[1] << 8) | val[0]


reader = raw12_reader(sys.argv[1])
data = it.islice(reader, RAW_WIDTH * RAW_HEIGHT)
array = np.fromiter(data, np.int)
raw = np.reshape(array, (RAW_HEIGHT, RAW_WIDTH), 'C')

plan_r = raw[::2, ::2]
plan_g1 = raw[::2, 1::2]
plan_g2 = raw[1::2, ::2]
plan_b = raw[1::2, 1::2]

flat_r = plan_r.flatten()
flat_g1 = plan_g1.flatten()
flat_g2 = plan_g2.flatten()
flat_b = plan_b.flatten()


IMG_WIDTH = RAW_WIDTH >> 1
IMG_HEIGHT = RAW_HEIGHT >> 1

MAX_VALUE = (1 << 12) - 1

print("P3")
print(IMG_WIDTH, IMG_HEIGHT)
print(MAX_VALUE)

for r, g1, g2, b in zip(flat_r, flat_g1, flat_g2, flat_b):
    g = (g1 + g2) >> 1
    print(r, g, b)

regs = it.islice(reader, NUM_REGS)

for idx, reg in enumerate(regs):
    print("# {} = {}".format(idx, reg))