# processors/cleaner.py

import os
import shutil
from core.constants import TRASH_FILES, IMAGE_EXTENSIONS, FOREIGN_ALLOWED
from core.result import StepResult


def clean_directory(work_dir: str) -> StepResult:
    """
    Elimina TRASH_FILES del directorio ya extraído.
    Elimina tanto ficheros como directorios de basura (e.g. __MACOSX).
    Sin I/O de archivo de cómic; trabaja sobre el directorio temporal.
    """
    removed = []
    for root, dirs, files in os.walk(work_dir, topdown=False):
        for f in files:
            if f.lower() in TRASH_FILES:
                full = os.path.join(root, f)
                os.remove(full)
                removed.append(os.path.relpath(full, work_dir))
            elif os.path.splitext(f)[1].lower() not in IMAGE_EXTENSIONS \
                    and f.lower() not in FOREIGN_ALLOWED:
                full = os.path.join(root, f)
                os.remove(full)
                removed.append(os.path.relpath(full, work_dir))
        for d in dirs:
            if d.lower() in TRASH_FILES:
                full = os.path.join(root, d)
                shutil.rmtree(full, ignore_errors=True)
                removed.append(os.path.relpath(full, work_dir) + "/")

    # Eliminar subdirectorios que hayan quedado vacíos
    for root, dirs, files in os.walk(work_dir, topdown=False):
        if root == work_dir:
            continue
        if not os.listdir(root):
            os.rmdir(root)
            removed.append(os.path.relpath(root, work_dir) + "/")

    details = [f"Eliminado: {r}" for r in removed]
    return StepResult(
        step="clean",
        changed=bool(removed),
        details=details,
    )


def flatten_directory(work_dir: str) -> StepResult:
    """
    Mueve imágenes de un único subdirectorio a la raíz de work_dir.
    Precondición: solo existe 1 subdir con imágenes (validado antes de llamar).
    """
    moved = []
    for entry in os.listdir(work_dir):
        subdir = os.path.join(work_dir, entry)
        if not os.path.isdir(subdir):
            continue
        for root, _dirs, files in os.walk(subdir):
            for f in files:
                src = os.path.join(root, f)
                dst = os.path.join(work_dir, f)
                if os.path.exists(dst):
                    base, ext = os.path.splitext(f)
                    counter = 1
                    while os.path.exists(dst):
                        dst = os.path.join(work_dir, f"{base}_{counter}{ext}")
                        counter += 1
                shutil.move(src, dst)
                moved.append(f)
        shutil.rmtree(subdir, ignore_errors=True)

    details = [f"Aplanado: {f}" for f in moved]
    return StepResult(step="flatten", changed=bool(moved), details=details)