#! /usr/bin/env python
"""Generate a word grid"""

import sys, re

from random import randrange, seed, choice
from string import ascii_uppercase

def placeHor(word, x, y):
    """Attempt to place word horizontally at position x/y"""
    if x + len(word) >= width:
        return False
    for i in range(len(word)):
        check = grid[y][x + i]
        if check != " " and check != word[i]:
            return False
    for i in range(len(word)):
        grid[y][x + i] = word[i]
    return True

def placeVert(word, x, y):
    """Attempt to place word vertically at position x/y"""
    if y + len(word) >= height:
        return False
    for i in range(len(word)):
        check = grid[y+i][x]
        if check != " " and check != word[i]:
            return False
    for i in range(len(word)):
        grid[y+i][x] = word[i]
    return True

# Setup
try:
    width = int(sys.argv[1])
    height = int(sys.argv[2])
    wordfile = sys.argv[3]
    seed()
except ValueError:
    print(f"Could not parse {', '.join(sys.argv[1:3])} as integers")
    sys.exit(1)
except IndexError:
    print(f"Usage: {sys.argv[0]} <width> <height> <dictionary>")
    sys.exit(2)

# Place a bunch of words on the grid
grid = [list(" " * width) for _ in range(height)]
try:
    with open(wordfile) as wordlist:
        lines = wordlist.read().splitlines()
        misses = 0
        maxtries = 200
        while misses < maxtries:
            word = choice(lines).strip().upper()
            if len(word) < 3 or not re.match("^[A-Z]*$", word):
                continue
            direction = choice([placeHor, placeVert])
            if direction(word, randrange(0,width), randrange(0,height)):
                # Word successfully placed
                misses = 0
            else:
                misses += 1
except FileNotFoundError:
    print(f"Could not open file {sys.argv[3]}")
    sys.exit(3)

# Fill all empty cells with random letters
for y in range(height):
    for x in range(width):
        if grid[y][x] == ' ':
            grid[y][x] = choice(ascii_uppercase)

for line in grid:
    print("".join(line))