"""路径与 Agent 目标定义。"""

from __future__ import annotations

from pathlib import Path

HOME = Path.home()
PREFERRED_POUCH_HOME = HOME / ".pouch"
LEGACY_POUCH_HOME = HOME / ".skills"
PROJECT_MANIFEST = ".pouch.yaml"
LEGACY_PROJECT_MANIFEST = ".skills.yaml"


def _first_existing_dir(*candidates: Path, default: Path) -> Path:
    for path in candidates:
        if path.is_dir():
            return path
    return default


def _first_existing_file(*candidates: Path, default: Path) -> Path:
    for path in candidates:
        if path.is_file():
            return path
    return default


POUCH_HOME = _first_existing_dir(
    PREFERRED_POUCH_HOME,
    LEGACY_POUCH_HOME,
    default=PREFERRED_POUCH_HOME,
)
SKILLS_DIR = POUCH_HOME / "skills"
TEMPLATE_DIR = SKILLS_DIR / "_template"
DRAFTS_DIR = POUCH_HOME / ".drafts"
CATALOG_FILE = POUCH_HOME / "catalog.yaml"
LEGACY_REGISTRY_FILE = POUCH_HOME / "registry.yaml"
CATALOG_CACHE_DIR = _first_existing_dir(
    HOME / ".local" / "share" / "pouch" / "externals",
    HOME / ".local" / "share" / "skills" / "externals",
    default=HOME / ".local" / "share" / "pouch" / "externals",
)
CONFIG_FILE = _first_existing_file(
    HOME / ".config" / "pouch" / "config.yaml",
    HOME / ".config" / "skiff" / "config.yaml",
    default=HOME / ".config" / "pouch" / "config.yaml",
)
SOURCES_DIR = _first_existing_dir(
    HOME / ".local" / "share" / "pouch" / "sources",
    HOME / ".local" / "share" / "skiff" / "sources",
    default=HOME / ".local" / "share" / "pouch" / "sources",
)

AGENT_GLOBAL: dict[str, Path] = {
    "cursor": HOME / ".cursor" / "skills",
    "claude": HOME / ".claude" / "skills",
    "codex": HOME / ".codex" / "skills",
    # agents 标准目录：OMP 原生 canonical（agents provider），cursor/codex 项目级同路径
    "agents": HOME / ".agents" / "skills",
}

AGENT_PROJECT: dict[str, str] = {
    "cursor": ".agents/skills",
    "claude": ".claude/skills",
    "codex": ".agents/skills",
    # 与 cursor/codex 共用 .agents/skills；软链幂等，同路径只写一次
    "agents": ".agents/skills",
}

ALL_TARGETS = ("cursor", "claude", "codex", "agents")


def project_manifest(root: Path) -> Path:
    """项目清单路径：优先 .pouch.yaml，否则沿用 .skills.yaml。"""
    preferred = root / PROJECT_MANIFEST
    legacy = root / LEGACY_PROJECT_MANIFEST
    if preferred.is_file():
        return preferred
    if legacy.is_file():
        return legacy
    return preferred


def resolve_targets(target: str | None) -> list[str]:
    if target is None or target == "all":
        return list(ALL_TARGETS)
    if target not in ALL_TARGETS:
        raise ValueError(f"未知 target: {target!r}，可选: {', '.join(ALL_TARGETS)}, all")
    return [target]


def agent_skill_dir(target: str, *, project_root: Path | None = None) -> Path:
    if project_root is None:
        return AGENT_GLOBAL[target]
    return project_root / AGENT_PROJECT[target]


def ensure_pouch_home() -> None:
    if not POUCH_HOME.is_dir():
        raise SystemExit(
            "~/.pouch 不存在。请将本仓库克隆到 ~/.pouch。"
            "若仍是 ~/.skills，先执行: mv ~/.skills ~/.pouch"
        )