"""Load settings.yaml. One place for every tunable value."""
import os
import yaml

PIPELINE_DIR = os.path.dirname(os.path.abspath(__file__))
REPO_ROOT = os.path.dirname(PIPELINE_DIR)


def load(path=None):
    path = path or os.environ.get("AUDIOBOOK_SETTINGS") or os.path.join(PIPELINE_DIR, "settings.yaml")
    with open(path, encoding="utf-8") as f:
        cfg = yaml.safe_load(f)
    cfg["_path"] = path
    apply_env(cfg)
    return cfg


# Environment variables that override settings.yaml (used by the CI job; nothing is hard-coded to a host).
ENV_OVERRIDES = [
    ("AUDIOBOOK_BOOKS_DIR", ("books_dir",)),
    ("AUDIOBOOK_WORK_DIR", ("work_dir",)),
    ("AUDIOBOOK_ARCHIVE_DIR", ("archive_dir",)),
    ("AUDIOBOOK_VOICE_ENDPOINT", ("voice", "endpoint")),
    ("AUDIOBOOK_LLM_ENDPOINT", ("llm", "endpoint")),
    ("AUDIOBOOK_LLM_MODEL", ("llm", "model")),
]


def apply_env(cfg, environ=None):
    environ = os.environ if environ is None else environ
    for var, keys in ENV_OVERRIDES:
        value = environ.get(var, "").strip()
        if value:
            node = cfg
            for k in keys[:-1]:
                node = node[k]
            node[keys[-1]] = value
    flag = environ.get("AUDIOBOOK_REQUIRE_OCR", "").strip().lower()
    if flag:
        cfg["ocr"]["required"] = flag in ("1", "true", "yes")


def resolve(cfg, key):
    """A path setting as an absolute path (relative values are relative to the repo root)."""
    value = cfg[key]
    return value if os.path.isabs(value) else os.path.join(REPO_ROOT, value)


def audio_dir(cfg, book_dir):
    """Where audio for a book goes: the book folder by default, else under archive_dir."""
    if not cfg.get("archive_dir"):
        return os.path.join(book_dir, "audio")
    base = cfg["archive_dir"]
    base = base if os.path.isabs(base) else os.path.join(REPO_ROOT, base)
    parts = os.path.normpath(book_dir).split(os.sep)[-2:]   # <author>/<book>
    return os.path.join(base, *parts, "audio")