"""Unified removal contract for every credential source Hermes reads from.

Hermes seeds its credential pool from many places:

    env:<VAR>     — os.environ / ~/.hermes/.env
    claude_code   — ~/.claude/.credentials.json
    hermes_pkce   — ~/.hermes/.anthropic_oauth.json
    device_code   — auth.json providers.<provider> (nous, openai-codex, ...)
    qwen-cli      — ~/.qwen/oauth_creds.json
    gh_cli        — gh auth token
    config:<name> — custom_providers config entry
    model_config  — model.api_key when model.provider == "custom"
    manual        — user ran `hermes auth add`

Each source has its own reader inside ``agent.credential_pool._seed_from_*``
(which keep their existing shape — we haven't restructured them).  What we
unify here is **removal**:

    ``hermes auth remove <provider> <N>`` must make the pool entry stay gone.

Before this module, every source had an ad-hoc removal branch in
``auth_remove_command``, and several sources had no branch at all — so
``auth remove`` silently reverted on the next ``load_pool()`` call for
qwen-cli, nous device_code (partial), hermes_pkce, copilot gh_cli, and
custom-config sources.

Now every source registers a ``RemovalStep`` that does exactly three things
in the same shape:

    1. Clean up whatever externally-readable state the source reads from
       (.env line, auth.json block, OAuth file, etc.)
    2. Suppress the ``(provider, source_id)`` in auth.json so the
       corresponding ``_seed_from_*`` branch skips the upsert on re-load
    3. Return ``RemovalResult`` describing what was cleaned and any
       diagnostic hints the user should see (shell-exported env vars,
       external credential files we deliberately don't delete, etc.)

Adding a new credential source is:
    - wire up a reader branch in ``_seed_from_*`` (existing pattern)
    - gate that reader behind ``is_source_suppressed(provider, source_id)``
    - register a ``RemovalStep`` here

No more per-source if/elif chain in ``auth_remove_command``.
"""

from __future__ import annotations

import os
from dataclasses import dataclass, field
from typing import Callable, List, Optional


@dataclass
class RemovalResult:
    """Outcome of removing a credential source.

    Attributes:
        cleaned: Short strings describing external state that was actually
            mutated (``"Cleared XAI_API_KEY from .env"``,
            ``"Cleared openai-codex OAuth tokens from auth store"``).
            Printed as plain lines to the user.
        hints: Diagnostic lines ABOUT state the user may need to clean up
            themselves or is deliberately left intact (shell-exported env
            var, Claude Code credential file we don't delete, etc.).
            Printed as plain lines to the user.  Always non-destructive.
        suppress: Whether to call ``suppress_credential_source`` after
            cleanup so future ``load_pool`` calls skip this source.
            Default True — almost every source needs this to stay sticky.
            The only legitimate False is ``manual`` entries, which aren't
            seeded from anywhere external.
    """

    cleaned: List[str] = field(default_factory=list)
    hints: List[str] = field(default_factory=list)
    suppress: bool = True


@dataclass
class RemovalStep:
    """How to remove one specific credential source cleanly.

    Attributes:
        provider: Provider pool key (``"xai"``, ``"anthropic"``, ``"nous"``, ...).
            Special value ``"*"`` means "matches any provider" — used for
            sources like ``manual`` that aren't provider-specific.
        source_id: Source identifier as it appears in
            ``PooledCredential.source``.  May be a literal (``"claude_code"``)
            or a prefix pattern matched via ``match_fn``.
        match_fn: Optional predicate overriding literal ``source_id``
            matching.  Gets the removed entry's source string.  Used for
            ``env:*`` (any env-seeded key), ``config:*`` (any custom
            pool), and ``manual:*`` (any manual-source variant).
        remove_fn: ``(provider, removed_entry) -> RemovalResult``.  Does the
            actual cleanup and returns what happened for the user.
        description: One-line human-readable description for docs / tests.
    """

    provider: str
    source_id: str
    remove_fn: Callable[..., RemovalResult]
    match_fn: Optional[Callable[[str], bool]] = None
    description: str = ""

    def matches(self, provider: str, source: str) -> bool:
        if self.provider != "*" and self.provider != provider:
            return False
        if self.match_fn is not None:
            return self.match_fn(source)
        return source == self.source_id


_REGISTRY: List[RemovalStep] = []


def register(step: RemovalStep) -> RemovalStep:
    _REGISTRY.append(step)
    return step


def find_removal_step(provider: str, source: str) -> Optional[RemovalStep]:
    """Return the first matching RemovalStep, or None if unregistered.

    Unregistered sources fall through to the default remove path in
    ``auth_remove_command``: the pool entry is already gone (that happens
    before dispatch), no external cleanup, no suppression.  This is the
    correct behaviour for ``manual`` entries — they were only ever stored
    in the pool, nothing external to clean up.
    """
    for step in _REGISTRY:
        if step.matches(provider, source):
            return step
    return None


# ---------------------------------------------------------------------------
# Individual RemovalStep implementations — one per source.
# ---------------------------------------------------------------------------
# Each remove_fn is intentionally small and single-purpose.  Adding a new
# credential source means adding ONE entry here — no other changes to
# auth_remove_command.


def _remove_env_source(provider: str, removed) -> RemovalResult:
    """env:<VAR> — the most common case.

    Handles three user situations:
      1. Var lives only in ~/.hermes/.env  → clear it
      2. Var lives only in the user's shell (shell profile, systemd
         EnvironmentFile, launchd plist) → hint them where to unset it
      3. Var lives in both → clear from .env, hint about shell
    """
    from hermes_cli.config import get_env_path, remove_env_value

    result = RemovalResult()
    env_var = removed.source[len("env:"):]
    if not env_var:
        return result

    # Detect shell vs .env BEFORE remove_env_value pops os.environ.
    env_in_process = bool(os.getenv(env_var))
    env_in_dotenv = False
    try:
        env_path = get_env_path()
        if env_path.exists():
            env_in_dotenv = any(
                line.strip().startswith(f"{env_var}=")
                for line in env_path.read_text(errors="replace").splitlines()
            )
    except OSError:
        pass
    shell_exported = env_in_process and not env_in_dotenv

    cleared = remove_env_value(env_var)
    if cleared:
        result.cleaned.append(f"Cleared {env_var} from .env")

    if shell_exported:
        result.hints.extend([
            f"Note: {env_var} is still set in your shell environment "
            f"(not in ~/.hermes/.env).",
            "  Unset it there (shell profile, systemd EnvironmentFile, "
            "launchd plist, etc.) or it will keep being visible to Hermes.",
            f"  The pool entry is now suppressed — Hermes will ignore "
            f"{env_var} until you run `hermes auth add {provider}`.",
        ])
    else:
        result.hints.append(
            f"Suppressed env:{env_var} — it will not be re-seeded even "
            f"if the variable is re-exported later."
        )
    return result


def _remove_claude_code(provider: str, removed) -> RemovalResult:
    """~/.claude/.credentials.json is owned by Claude Code itself.

    We don't delete it — the user's Claude Code install still needs to
    work.  We just suppress it so Hermes stops reading it.
    """
    return RemovalResult(hints=[
        "Suppressed claude_code credential — it will not be re-seeded.",
        "Note: Claude Code credentials still live in ~/.claude/.credentials.json",
        "Run `hermes auth add anthropic` to re-enable if needed.",
    ])


def _remove_hermes_pkce(provider: str, removed) -> RemovalResult:
    """~/.hermes/.anthropic_oauth.json is ours — delete it outright."""
    from hermes_constants import get_hermes_home

    result = RemovalResult()
    oauth_file = get_hermes_home() / ".anthropic_oauth.json"
    if oauth_file.exists():
        try:
            oauth_file.unlink()
            result.cleaned.append("Cleared Hermes Anthropic OAuth credentials")
        except OSError as exc:
            result.hints.append(f"Could not delete {oauth_file}: {exc}")
    return result


def _clear_auth_store_provider(provider: str) -> bool:
    """Delete auth_store.providers[provider].  Returns True if deleted."""
    from hermes_cli.auth import (
        _auth_store_lock,
        _load_auth_store,
        _save_auth_store,
    )

    with _auth_store_lock():
        auth_store = _load_auth_store()
        providers_dict = auth_store.get("providers")
        if isinstance(providers_dict, dict) and provider in providers_dict:
            del providers_dict[provider]
            _save_auth_store(auth_store)
            return True
    return False


def _remove_nous_device_code(provider: str, removed) -> RemovalResult:
    """Nous OAuth lives in auth.json providers.nous — clear it and suppress.

    We suppress in addition to clearing because nothing else stops a future
    `hermes auth add nous` (or any other path that writes providers.nous)
    from re-seeding before the user has decided to.  Suppression forces
    them to go through `hermes auth add nous` to re-engage, which is the
    documented re-add path and clears the suppression atomically.
    """
    result = RemovalResult()
    if _clear_auth_store_provider(provider):
        result.cleaned.append(f"Cleared {provider} OAuth tokens from auth store")
    return result


def _remove_minimax_oauth(provider: str, removed) -> RemovalResult:
    """MiniMax OAuth lives in auth.json providers.minimax-oauth — clear it.

    Same pattern as Nous: single-source OAuth state with refresh tokens.
    Suppression of the `oauth` source ensures the pool reseed path
    (_seed_from_singletons) doesn't instantly undo the removal.
    """
    result = RemovalResult()
    if _clear_auth_store_provider(provider):
        result.cleaned.append(f"Cleared {provider} OAuth tokens from auth store")
    return result


def _remove_xai_oauth_loopback_pkce(provider: str, removed) -> RemovalResult:
    """xAI OAuth tokens live in auth.json providers.xai-oauth — clear them.

    Without this step, ``hermes auth remove xai-oauth <N>`` silently undoes
    itself: the central dispatcher only removes the in-memory pool entry,
    leaves ``providers.xai-oauth`` in auth.json intact, and on the next
    ``load_pool("xai-oauth")`` call ``_seed_from_singletons`` re-seeds the
    entry from the still-present singleton — credentials reappear with no
    user feedback. Clearing the singleton in step with the suppression set
    by the central dispatcher makes the removal stick.

    Belt-and-braces against the manual entry path: ``hermes auth add
    xai-oauth`` produces a ``manual:xai_pkce`` entry whose removal step
    falls through to "unregistered → nothing to clean up" (correct —
    manual entries are pool-only).
    """
    result = RemovalResult()
    if _clear_auth_store_provider(provider):
        result.cleaned.append(f"Cleared {provider} OAuth tokens from auth store")
    result.hints.append(
        "Run `hermes model` → xAI Grok OAuth (SuperGrok / Premium+) to re-authenticate if needed."
    )
    return result


def _remove_codex_device_code(provider: str, removed) -> RemovalResult:
    """Codex tokens live in TWO places: our auth store AND ~/.codex/auth.json.

    refresh_codex_oauth_pure() writes both every time, so clearing only
    the Hermes auth store is not enough — _seed_from_singletons() would
    re-import from ~/.codex/auth.json on the next load_pool() call and
    the removal would be instantly undone.  We suppress instead of
    deleting Codex CLI's file, so the Codex CLI itself keeps working.

    The canonical source name in ``_seed_from_singletons`` is
    ``"device_code"`` (no prefix).  Entries may show up in the pool as
    either ``"device_code"`` (seeded) or ``"manual:device_code"`` (added
    via ``hermes auth add openai-codex``), but in both cases the re-seed
    gate lives at the ``"device_code"`` suppression key.  We suppress
    that canonical key here; the central dispatcher also suppresses
    ``removed.source`` which is fine — belt-and-suspenders, idempotent.
    """
    from hermes_cli.auth import suppress_credential_source

    result = RemovalResult()
    if _clear_auth_store_provider(provider):
        result.cleaned.append(f"Cleared {provider} OAuth tokens from auth store")
    # Suppress the canonical re-seed source, not just whatever source the
    # removed entry had.  Otherwise `manual:device_code` removals wouldn't
    # block the `device_code` re-seed path.
    suppress_credential_source(provider, "device_code")
    result.hints.extend([
        "Suppressed openai-codex device_code source — it will not be re-seeded.",
        "Note: Codex CLI credentials still live in ~/.codex/auth.json",
        "Run `hermes auth add openai-codex` to re-enable if needed.",
    ])
    return result


def _remove_qwen_cli(provider: str, removed) -> RemovalResult:
    """~/.qwen/oauth_creds.json is owned by the Qwen CLI.

    Same pattern as claude_code — suppress, don't delete.  The user's
    Qwen CLI install still reads from that file.
    """
    return RemovalResult(hints=[
        "Suppressed qwen-cli credential — it will not be re-seeded.",
        "Note: Qwen CLI credentials still live in ~/.qwen/oauth_creds.json",
        "Run `hermes auth add qwen-oauth` to re-enable if needed.",
    ])


def _remove_copilot_gh(provider: str, removed) -> RemovalResult:
    """Copilot token comes from `gh auth token` or COPILOT_GITHUB_TOKEN / GH_TOKEN / GITHUB_TOKEN.

    Copilot is special: the same token can be seeded as multiple source
    entries (gh_cli from ``_seed_from_singletons`` plus env:<VAR> from
    ``_seed_from_env``), so removing one entry without suppressing the
    others lets the duplicates resurrect.  We suppress ALL known copilot
    sources here so removal is stable regardless of which entry the
    user clicked.

    We don't touch the user's gh CLI or shell state — just suppress so
    Hermes stops picking the token up.
    """
    # Suppress ALL copilot source variants up-front so no path resurrects
    # the pool entry.  The central dispatcher in auth_remove_command will
    # ALSO suppress removed.source, but it's idempotent so double-calling
    # is harmless.
    from hermes_cli.auth import suppress_credential_source
    suppress_credential_source(provider, "gh_cli")
    for env_var in ("COPILOT_GITHUB_TOKEN", "GH_TOKEN", "GITHUB_TOKEN"):
        suppress_credential_source(provider, f"env:{env_var}")

    return RemovalResult(hints=[
        "Suppressed all copilot token sources (gh_cli + env vars) — they will not be re-seeded.",
        "Note: Your gh CLI / shell environment is unchanged.",
        "Run `hermes auth add copilot` to re-enable if needed.",
    ])


def _remove_custom_config(provider: str, removed) -> RemovalResult:
    """Custom provider pools are seeded from custom_providers config or
    model.api_key.  Both are in config.yaml — modifying that from here
    is more invasive than suppression.  We suppress; the user can edit
    config.yaml if they want to remove the key from disk entirely.
    """
    source_label = removed.source
    return RemovalResult(hints=[
        f"Suppressed {source_label} — it will not be re-seeded.",
        "Note: The underlying value in config.yaml is unchanged.  Edit it "
        "directly if you want to remove the credential from disk.",
    ])


def _register_all_sources() -> None:
    """Called once on module import.

    ORDER MATTERS — ``find_removal_step`` returns the first match.  Put
    provider-specific steps before the generic ``env:*`` step so that e.g.
    copilot's ``env:GH_TOKEN`` goes through the copilot removal (which
    doesn't touch the user's shell), not the generic env-var removal
    (which would try to clear .env).
    """
    register(RemovalStep(
        provider="copilot", source_id="gh_cli",
        match_fn=lambda src: src == "gh_cli" or src.startswith("env:"),
        remove_fn=_remove_copilot_gh,
        description="gh auth token / COPILOT_GITHUB_TOKEN / GH_TOKEN",
    ))
    register(RemovalStep(
        provider="*", source_id="env:",
        match_fn=lambda src: src.startswith("env:"),
        remove_fn=_remove_env_source,
        description="Any env-seeded credential (XAI_API_KEY, DEEPSEEK_API_KEY, etc.)",
    ))
    register(RemovalStep(
        provider="anthropic", source_id="claude_code",
        remove_fn=_remove_claude_code,
        description="~/.claude/.credentials.json",
    ))
    register(RemovalStep(
        provider="anthropic", source_id="hermes_pkce",
        remove_fn=_remove_hermes_pkce,
        description="~/.hermes/.anthropic_oauth.json",
    ))
    register(RemovalStep(
        provider="nous", source_id="device_code",
        remove_fn=_remove_nous_device_code,
        description="auth.json providers.nous",
    ))
    register(RemovalStep(
        provider="openai-codex", source_id="device_code",
        match_fn=lambda src: src == "device_code" or src.endswith(":device_code"),
        remove_fn=_remove_codex_device_code,
        description="auth.json providers.openai-codex + ~/.codex/auth.json",
    ))
    register(RemovalStep(
        provider="xai-oauth", source_id="loopback_pkce",
        remove_fn=_remove_xai_oauth_loopback_pkce,
        description="auth.json providers.xai-oauth",
    ))
    register(RemovalStep(
        provider="qwen-oauth", source_id="qwen-cli",
        remove_fn=_remove_qwen_cli,
        description="~/.qwen/oauth_creds.json",
    ))
    register(RemovalStep(
        provider="minimax-oauth", source_id="oauth",
        remove_fn=_remove_minimax_oauth,
        description="auth.json providers.minimax-oauth",
    ))
    register(RemovalStep(
        provider="*", source_id="config:",
        match_fn=lambda src: src.startswith("config:") or src == "model_config",
        remove_fn=_remove_custom_config,
        description="Custom provider config.yaml api_key field",
    ))


_register_all_sources()
