"""Static answer to "will this plugin run in the plugin host?" (``plugins.isolation: host``).

Reads a plugin directory's manifest and Python source (never imports it) and reports whether the
plugin reaches Hermes only through ``ctx`` surfaces that cross the host boundary. The rules come
from :mod:`hermes_cli.plugin_isolation`, the same tables the host enforces at runtime, so a plugin
the audit calls host-ready loads in the host, and one it flags fails there with the same reason.

What it cannot see in a process boundary it flags:

* ctx methods that hand over live objects (platform adapters, SDK clients, argparse);
* writing attributes of Hermes modules (monkeypatching): the patch lands in the host's copy;
* mutating a global registry directly instead of through ``ctx``: the registration lands in the
  host's registry, which Hermes never reads;
* gateway platform adapters (``kind: platform``), model-provider profiles that build their own SDK
  client (``create_client``), and dashboard APIs that stream (the host bridge buffers responses).

``hermes plugins validate`` prints the verdict; ``evals/plugin_isolation/audit_catalog.py`` runs it
over every catalog entry.
"""

from __future__ import annotations

import ast
from dataclasses import dataclass, field
from pathlib import Path
from typing import Any, Dict, List, Mapping, Optional, Set

VERDICT_HOST = "host"
VERDICT_IN_PROCESS = "in_process"
VERDICT_PORTABLE = "portable"

# Top-level packages that are Hermes's own process state when imported by a plugin.
HERMES_PACKAGES: frozenset = frozenset({
    "agent", "tools", "hermes_cli", "gateway", "cron", "providers", "plugins", "tui_gateway",
    "acp_adapter", "run_agent", "cli", "model_tools", "toolsets", "hermes_state", "hermes_constants",
    "hermes_logging", "hermes_time", "utils", "registration_lifecycle", "hermes_platform",
})
# ``<module>.<callable>`` that mutate a Hermes-process registry when called from plugin code.
_DIRECT_REGISTRY_CALLS: frozenset = frozenset({
    ("tools.registry", "register"), ("tools.registry", "deregister"),
    ("gateway.platform_registry", "register"), ("providers", "register_provider"),
})
_MANIFEST_KIND_REASONS: dict[str, str] = {
    "platform": "kind 'platform': gateway platform adapters run in the Hermes process",
}
_STREAMING_MARKERS = ("StreamingResponse", "EventSourceResponse", ".websocket(", "WebSocket")
_SKIP_DIRS = frozenset({"tests", "test", ".git", "__pycache__", "node_modules", ".venv", "venv", "docs"})


@dataclass
class IsolationReport:
    verdict: str
    reasons: list[str] = field(default_factory=list)
    notes: list[str] = field(default_factory=list)
    ctx_methods: set[str] = field(default_factory=set)

    @property
    def host_ready(self) -> bool:
        return self.verdict in {VERDICT_HOST, VERDICT_PORTABLE}

    def summary(self) -> str:
        if self.verdict == VERDICT_PORTABLE:
            return "portable plugin (no Python): runs anywhere"
        if self.verdict == VERDICT_HOST:
            return "runs in the plugin host (plugins.isolation: host)"
        return "in-process only: " + "; ".join(self.reasons)

    def to_dict(self) -> dict[str, Any]:
        return {"verdict": self.verdict, "host_ready": self.host_ready, "reasons": list(self.reasons),
                "notes": list(self.notes), "ctx_methods": sorted(self.ctx_methods)}


def _python_files(plugin_dir: Path) -> list[Path]:
    files = []
    for path in sorted(plugin_dir.rglob("*.py")):
        rel = path.relative_to(plugin_dir).parts
        if any(part in _SKIP_DIRS or part.startswith(".") for part in rel[:-1]):
            continue
        if rel[-1].startswith("test_") or rel[-1] == "conftest.py":
            continue
        files.append(path)
    return files


class _SourceVisitor(ast.NodeVisitor):
    """Collects ctx method calls, Hermes-module aliases, and writes through those aliases."""

    def __init__(self, rel: str, *, model_provider: bool = False):
        from hermes_cli.plugin_isolation import (
            HOST_DEGRADED_HOOKS, HOST_OBJECT_BASES, HOST_SKIPPED_CTX_METHODS, HOST_UNSUPPORTED_CTX_METHODS,
        )
        self._unsupported, self._skipped = HOST_UNSUPPORTED_CTX_METHODS, HOST_SKIPPED_CTX_METHODS
        self._degraded, self._object_methods = HOST_DEGRADED_HOOKS, HOST_OBJECT_BASES
        self.rel = rel
        # A model-provider plugin's register_provider() call is its contract; the host captures it.
        self.model_provider = model_provider
        self.aliases: dict[str, str] = {}  # local name -> hermes module path (or module.attr)
        self.reasons: list[str] = []
        self.notes: list[str] = []
        self.ctx_methods: set[str] = set()

    def _hermes(self, module: str) -> bool:
        return module.split(".")[0] in HERMES_PACKAGES

    def visit_Import(self, node: ast.Import) -> None:
        for alias in node.names:
            if self._hermes(alias.name):
                self.aliases[alias.asname or alias.name.split(".")[0]] = (
                    alias.name if alias.asname else alias.name.split(".")[0])

    def visit_ImportFrom(self, node: ast.ImportFrom) -> None:
        if node.level == 0 and node.module and self._hermes(node.module):
            for alias in node.names:
                self.aliases[alias.asname or alias.name] = f"{node.module}.{alias.name}"

    def _resolve(self, node: ast.AST) -> Optional[str]:
        if isinstance(node, ast.Name):
            return self.aliases.get(node.id)
        if isinstance(node, ast.Attribute):
            base = self._resolve(node.value)
            return f"{base}.{node.attr}" if base else None
        return None

    def _flag_write(self, target: ast.AST, line: int) -> None:
        if isinstance(target, ast.Attribute):
            owner = self._resolve(target.value)
            if owner:
                self.reasons.append(f"{self.rel}:{line} patches {owner}.{target.attr} (a Hermes module "
                                    f"attribute; the host's copy is not the one Hermes runs)")

    def visit_Assign(self, node: ast.Assign) -> None:
        for target in node.targets:
            self._flag_write(target, node.lineno)
        self.generic_visit(node)

    def visit_AugAssign(self, node: ast.AugAssign) -> None:
        self._flag_write(node.target, node.lineno)
        self.generic_visit(node)

    def visit_Call(self, node: ast.Call) -> None:
        func = node.func
        if isinstance(func, ast.Name) and func.id == "setattr" and node.args:
            owner = self._resolve(node.args[0])
            if owner:
                self.reasons.append(f"{self.rel}:{node.lineno} setattr() on {owner} (patches a Hermes module)")
        if isinstance(func, ast.Attribute):
            name = func.attr
            if name in self._unsupported:
                self.reasons.append(f"{self.rel}:{node.lineno} ctx.{name}(): {self._unsupported[name]}")
            elif name in self._skipped:
                self.notes.append(f"ctx.{name}() is skipped in the host ({self._skipped[name]})")
            if name.startswith("register_") or name in {"subscribe", "dispatch_tool", "inject_message", "emit"}:
                self.ctx_methods.add(name)
            if name == "register_hook" and node.args and isinstance(node.args[0], ast.Constant) \
                    and node.args[0].value in self._degraded:
                hook = node.args[0].value
                self.notes.append(f"hook {hook} {self._degraded[hook]}; those fields are placeholders in the host")
            self._flag_registry_call(self._resolve(func), node.lineno)
        elif isinstance(func, ast.Name):
            self._flag_registry_call(self.aliases.get(func.id), node.lineno)
        self.generic_visit(node)

    def _flag_registry_call(self, target: Optional[str], line: int) -> None:
        if not target:
            return
        module, _, attr = target.rpartition(".")
        if self.model_provider and (module, attr) == ("providers", "register_provider"):
            return
        if (module, attr) in _DIRECT_REGISTRY_CALLS or (
                module.endswith("_registry") and attr in {"register", "register_provider"}):
            self.reasons.append(f"{self.rel}:{line} calls {target}() directly instead of "
                                f"through ctx (registers in the host, not in Hermes)")

    def visit_ClassDef(self, node: ast.ClassDef) -> None:
        if self.model_provider and any(isinstance(item, (ast.FunctionDef, ast.AsyncFunctionDef))
                                       and item.name == "create_client" for item in node.body):
            self.reasons.append(f"{self.rel}:{node.lineno} {node.name}.create_client() returns a live SDK "
                                f"client (model-provider profiles cross the host as data + methods)")
        self.generic_visit(node)


def audit_plugin_dir(plugin_dir: Path, manifest: Optional[Mapping[str, Any]] = None) -> IsolationReport:
    """Classify one plugin directory without importing it."""
    plugin_dir = Path(plugin_dir)
    if manifest is None:
        manifest = _read_manifest(plugin_dir)
    if not (plugin_dir / "__init__.py").is_file():
        return IsolationReport(VERDICT_PORTABLE)
    reasons: list[str] = []
    notes: list[str] = []
    ctx_methods: set[str] = set()
    kind = str((manifest or {}).get("kind") or "").strip().lower()
    if kind in _MANIFEST_KIND_REASONS:
        reasons.append(_MANIFEST_KIND_REASONS[kind])
    dashboard = plugin_dir / "dashboard"
    if (dashboard / "manifest.json").is_file() and '"api"' in (dashboard / "manifest.json").read_text(
            encoding="utf-8", errors="replace"):
        api_source = "".join(p.read_text(encoding="utf-8-sig", errors="replace") for p in dashboard.rglob("*.py"))
        if any(marker in api_source for marker in _STREAMING_MARKERS):
            reasons.append("dashboard backend API streams (SSE/websocket); the host bridge buffers responses")
        else:
            notes.append("dashboard backend API is served through the plugin host (buffered responses)")
    for path in _python_files(plugin_dir):
        rel = str(path.relative_to(plugin_dir))
        try:
            tree = ast.parse(path.read_text(encoding="utf-8-sig", errors="replace"), filename=rel)
        except SyntaxError as exc:
            notes.append(f"{rel}: not parseable ({exc.msg}); not audited")
            continue
        visitor = _SourceVisitor(rel, model_provider=kind == "model-provider")
        visitor.visit(tree)
        reasons.extend(visitor.reasons)
        notes.extend(visitor.notes)
        ctx_methods |= visitor.ctx_methods
    verdict = VERDICT_IN_PROCESS if reasons else VERDICT_HOST
    return IsolationReport(verdict, _dedupe(reasons), _dedupe(notes), ctx_methods)


def _dedupe(items: list[str]) -> list[str]:
    return list(dict.fromkeys(items))


def _read_manifest(plugin_dir: Path) -> dict[str, Any]:
    for name in ("plugin.yaml", "plugin.yml"):
        path = plugin_dir / name
        if path.is_file():
            try:
                import hermes_yaml as yaml
                data = yaml.safe_load(path.read_text(encoding="utf-8-sig"))
                return data if isinstance(data, dict) else {}
            except Exception:
                return {}
    return {}