"""CLI entry point for the Crossword KDP Book Generator."""

import logging
import sys

import click

from csv_reader import CSVValidationError, read_csv
from generator import generate_batch
from kdp_format import render_kdp_book
from models import TRIM_SIZES, PuzzleBook


@click.command()
@click.option("--input", "input_path", required=True,
              type=click.Path(exists=True, dir_okay=False),
              help="Path to a CSV file with word,clue columns.")
@click.option("--output", "output_path", default="output.pdf",
              show_default=True,
              help="Output PDF file path.")
@click.option("--puzzles", default=20, show_default=True,
              help="Number of crossword puzzles to generate.")
@click.option("--grid-size", default=13, show_default=True,
              help="Grid dimensions (e.g. 15 for a 15×15 grid).")
@click.option("--trim-size", default="8.5x11", show_default=True,
              type=click.Choice(list(TRIM_SIZES.keys())),
              help="KDP page trim size.")
@click.option("--title", default="Crossword Puzzles", show_default=True,
              help="Book title for the cover page.")
@click.option("--author", default="", help="Author name.")
@click.option("--words-per-puzzle", default=20, show_default=True,
              help="Target number of words per puzzle.")
@click.option("--solutions-at-end", is_flag=True, default=False,
              help="Group all solution pages at the back of the book.")
@click.option("--seed", default=None, type=int,
              help="Random seed for reproducible output.")
@click.option("--no-toc", is_flag=True, default=False,
              help="Omit the table of contents page.")
@click.option("--no-instructions", is_flag=True, default=False,
              help="Omit the how-to-solve instructions page.")
@click.option("-v", "--verbose", is_flag=True, default=False,
              help="Enable verbose logging.")
def main(input_path: str, output_path: str, puzzles: int, grid_size: int,
         trim_size: str, title: str, author: str, words_per_puzzle: int,
         solutions_at_end: bool, seed: int | None, no_toc: bool,
         no_instructions: bool, verbose: bool) -> None:
    """Generate a KDP-ready crossword puzzle book from a CSV word list."""

    logging.basicConfig(
        level=logging.DEBUG if verbose else logging.INFO,
        format="%(levelname)s: %(message)s",
    )

    # -- read & validate CSV -------------------------------------------------
    try:
        word_clues = read_csv(input_path, min_words=3,
                              max_word_length=grid_size)
    except (CSVValidationError, FileNotFoundError) as exc:
        click.echo(f"Error: {exc}", err=True)
        sys.exit(1)

    click.echo(f"Loaded {len(word_clues)} words from {input_path}.")

    # -- generate puzzles ----------------------------------------------------
    click.echo(f"Generating {puzzles} puzzle(s) "
               f"({words_per_puzzle} words each, {grid_size}×{grid_size} grid)…")

    generated = generate_batch(
        word_clues,
        count=puzzles,
        words_per_puzzle=words_per_puzzle,
        grid_size=grid_size,
        seed=seed,
    )

    if not generated:
        click.echo("Error: could not generate any puzzles. "
                   "Try a larger word list or smaller grid.", err=True)
        sys.exit(1)

    if len(generated) < puzzles:
        click.echo(f"Warning: only {len(generated)}/{puzzles} puzzles met "
                   f"quality thresholds.", err=True)

    click.echo(f"Generated {len(generated)} puzzle(s).")

    # -- assemble KDP book ---------------------------------------------------
    book = PuzzleBook(
        title=title,
        author=author,
        puzzles=generated,
        trim_size=TRIM_SIZES[trim_size],
        solutions_at_end=solutions_at_end,
    )

    try:
        total_pages = render_kdp_book(
            book, output_path,
            include_toc=not no_toc,
            include_instructions=not no_instructions,
        )
    except ValueError as exc:
        click.echo(f"Error: {exc}", err=True)
        sys.exit(1)

    click.echo(f"Wrote {total_pages}-page KDP book to {output_path}.")


if __name__ == "__main__":
    main()