"""
CLI commands for checking and fixing image instruction page order.

Lives in its own module rather than in cli.py so the page-ordering work stays
together: the logic is in app/services/page_order.py and the commands that
drive it are here.

    flask pages audit                      which sets have broken numbering
    flask pages fix --dry-run              what would be repaired
    flask pages fix                        repair every set that needs it
    flask pages fix --set 60123            repair one set
    flask pages sort 60123 --by filename   reorder one set
    flask pages sort 60123 --by page_hint --reverse

Created by: Jess Rogerson (yelling commands at Claude.AI)
"""

import click
from flask.cli import AppGroup

pages_cli = AppGroup(
    'pages', help='Check and fix the page order of image instructions.')


def _sets_with_images():
    """Every set that has at least one image page, in set-number order."""
    from app import db
    from app.models.set import Set
    from app.models.instruction import Instruction

    ids = [row[0] for row in db.session.query(Instruction.set_id)
           .filter(Instruction.file_type == 'IMAGE').distinct()]
    return Set.query.filter(Set.id.in_(ids)).order_by(Set.set_number).all()


@pages_cli.command('audit')
@click.option('--all/--problems', 'show_all', default=False,
              help='List every set, or only the ones with a numbering problem '
                   '(default).')
def pages_audit(show_all):
    """Report duplicate, missing or unnumbered pages across the library."""
    from app.services import page_order

    problems = 0
    for lego_set in _sets_with_images():
        report = page_order.audit(lego_set.id)
        if report['is_clean'] and not show_all:
            continue
        if not report['is_clean']:
            problems += 1

        state = 'ok' if report['is_clean'] else 'NEEDS FIXING'
        colour = 'green' if report['is_clean'] else 'yellow'
        click.secho(f"{lego_set.set_number:<12} {report['total']:>4} pages  "
                    f"{state}", fg=colour)
        if report['duplicates']:
            click.echo(f"    duplicates : {report['duplicates']}")
        if report['gaps']:
            click.echo(f"    gaps       : {report['gaps']}")
        if report['unnumbered']:
            click.echo(f"    unnumbered : {report['unnumbered']}")

    click.echo(f"\n{problems} set(s) need fixing.")


@pages_cli.command('fix')
@click.option('--set', 'set_number', default=None,
              help='One set number. Omit to fix every set that needs it.')
@click.option('--dry-run', is_flag=True, help='Report without writing.')
def pages_fix(set_number, dry_run):
    """Renumber pages 1..n, closing gaps and clearing duplicates."""
    from app.models.set import Set
    from app.services import page_order

    if set_number:
        targets = Set.query.filter_by(set_number=set_number).all()
        if not targets:
            raise click.ClickException(f'No set numbered {set_number}')
    else:
        targets = _sets_with_images()

    fixed = 0
    for lego_set in targets:
        report = page_order.audit(lego_set.id)
        if report['is_clean']:
            continue
        fixed += 1
        if dry_run:
            click.echo(f"would fix {lego_set.set_number} "
                       f"({report['total']} pages)")
            continue
        page_order.renumber(lego_set.id)
        click.secho(f"fixed {lego_set.set_number} ({report['total']} pages)",
                    fg='green')

    click.echo(f"{fixed} set(s) {'would be ' if dry_run else ''}fixed.")


@pages_cli.command('sort')
@click.argument('set_number')
@click.option('--by', 'strategy', default='filename',
              help='filename, page_hint, uploaded or size.')
@click.option('--reverse', is_flag=True, help='Sort the other way round.')
def pages_sort(set_number, strategy, reverse):
    """Reorder one set's image pages by filename, upload order or size."""
    from app.models.set import Set
    from app.services import page_order

    lego_set = Set.query.filter_by(set_number=set_number).first()
    if lego_set is None:
        raise click.ClickException(f'No set numbered {set_number}')

    try:
        pages = page_order.auto_sort(lego_set.id, strategy, reverse=reverse)
    except ValueError as e:
        raise click.ClickException(str(e))

    for page in pages:
        click.echo(f"  {page.page_number:>4}  {page.file_name}")
    click.secho(f'Sorted {len(pages)} pages.', fg='green')


def register_pages_cli(app):
    """Attach the `flask pages` group to `app`."""
    app.cli.add_command(pages_cli)