"""Turn-end verification guard for coding edits.

This module is intentionally policy-only. It never runs checks itself; it turns
the passive verification ledger into a bounded follow-up when the model tries to
finish immediately after editing code without fresh evidence.
"""

from __future__ import annotations

import os
import tempfile
from pathlib import Path
from typing import Any, Iterable


_MAX_CHANGED_PATHS_IN_NUDGE = 8

# Non-code file extensions whose edits carry no verifiable runtime behavior:
# documentation, prose, and data/markup that no test/build exercises. When a
# turn touches ONLY these, verify-on-stop has nothing to check, so the nudge is
# suppressed (this is fix "C" for the doc/markdown/skill false-positive — a
# SKILL.md or README edit must never demand a /tmp verification script). A turn
# that edits any non-listed path (a real source/code/config file) still nudges.
_NON_CODE_VERIFY_EXTENSIONS = frozenset(
    {
        ".md",
        ".markdown",
        ".mdx",
        ".rst",
        ".txt",
        ".text",
        ".adoc",
        ".asciidoc",
        ".org",
        ".log",
        ".csv",
        ".tsv",
    }
)

# Filenames (case-insensitive, extension-less or otherwise) that are pure prose
# even without a recognized doc extension.
_NON_CODE_VERIFY_FILENAMES = frozenset(
    {
        "license",
        "licence",
        "notice",
        "authors",
        "contributors",
        "changelog",
        "codeowners",
    }
)


def _is_non_code_path(raw: str) -> bool:
    """Return True when a changed path is documentation/prose with nothing to verify."""
    try:
        p = Path(str(raw))
    except Exception:
        return False
    suffix = p.suffix.lower()
    if suffix in _NON_CODE_VERIFY_EXTENSIONS:
        return True
    if not suffix and p.name.lower() in _NON_CODE_VERIFY_FILENAMES:
        return True
    return False


def _filter_verifiable_paths(paths: Iterable[str]) -> list[str]:
    """Drop documentation/prose paths; keep paths that could have verifiable behavior."""
    return [p for p in paths if p and not _is_non_code_path(p)]


# Session identities (platform or source) that are NOT human conversational
# messaging surfaces: interactive coding surfaces (CLI, TUI, desktop, codex,
# local, gateway) and programmatic callers (API server, webhooks, tools).
# Verify-on-stop stays ON by default for these. Any other resolved gateway
# platform is a conversational messaging surface (Telegram, Discord, WhatsApp,
# Signal, Slack, etc.) where the verification narrative would reach a human as
# chat noise, so it defaults OFF. Mirrors LOCAL_SESSION_SOURCE_IDS in
# apps/desktop/src/lib/session-source.ts; keep roughly in sync when adding a
# local or programmatic surface. Default-deny by design: an unrecognized
# identity is treated as messaging (OFF) so a new chat platform never leaks the
# verification receipt before this set is updated.
_NON_MESSAGING_SESSION_SURFACES = frozenset(
    {
        "",
        "cli",
        "codex",
        "desktop",
        "gateway",
        "local",
        "tui",
        "tool",
        "api_server",
        "webhook",
        "msgraph_webhook",
    }
)


def _session_is_messaging_surface() -> bool:
    """Return whether this turn is delivered over a human messaging channel.

    The gateway binds the platform value (e.g. ``telegram``) to
    ``HERMES_SESSION_PLATFORM``; the CLI and TUI set ``HERMES_SESSION_SOURCE``
    (e.g. ``cli``, ``tui``) instead. Both are consulted via the session-context
    helper (with an ``os.environ`` fallback), alongside the ``HERMES_PLATFORM``
    override, matching the sibling platform resolution in
    ``agent/skill_commands.py`` and ``agent/prompt_builder.py``. A turn is a
    messaging surface when a resolved identity is present and is not a known
    non-messaging surface.
    """
    try:
        from gateway.session_context import get_session_env

        platform = (
            os.getenv("HERMES_PLATFORM")
            or get_session_env("HERMES_SESSION_PLATFORM", "")
        )
        source = get_session_env("HERMES_SESSION_SOURCE", "")
    except Exception:
        platform = os.getenv("HERMES_PLATFORM", "") or os.environ.get(
            "HERMES_SESSION_PLATFORM", ""
        )
        source = os.environ.get("HERMES_SESSION_SOURCE", "")
    for identity in (platform, source):
        identity = str(identity or "").strip().lower()
        if identity and identity not in _NON_MESSAGING_SESSION_SURFACES:
            return True
    return False


def verify_on_stop_enabled(config: dict[str, Any] | None = None) -> bool:
    """Return whether edit -> verify-before-finish behavior is enabled.

    Precedence: an explicit ``HERMES_VERIFY_ON_STOP`` env var wins, then an
    explicit ``agent.verify_on_stop`` config value. The config default is
    ``"auto"`` (see ``DEFAULT_CONFIG``) — surface-aware: ON for interactive
    coding surfaces (CLI, TUI, desktop) and programmatic callers, OFF for
    conversational messaging surfaces (Telegram, Discord, etc.) where the
    verification narrative would reach a human as chat noise. An explicit
    bool forces the behavior in either direction. A missing or unrecognized
    value falls back to the surface-aware ``"auto"`` default.
    """
    env = os.environ.get("HERMES_VERIFY_ON_STOP")
    if env is not None:
        return env.strip().lower() not in {"0", "false", "no", "off"}
    if config is None:
        try:
            from hermes_cli.config import load_config

            config = load_config()
        except Exception:
            config = {}
    agent_cfg = (config or {}).get("agent") if isinstance(config, dict) else None
    cfg_val = agent_cfg.get("verify_on_stop") if isinstance(agent_cfg, dict) else None
    if isinstance(cfg_val, bool):
        return cfg_val
    if isinstance(cfg_val, str):
        token = cfg_val.strip().lower()
        if token in {"1", "true", "yes", "on"}:
            return True
        if token in {"0", "false", "no", "off"}:
            return False
        if token == "auto":
            return not _session_is_messaging_surface()
    # Missing or unrecognized value -> surface-aware "auto" default.
    return not _session_is_messaging_surface()


def _candidate_cwds(paths: Iterable[str]) -> list[Path]:
    candidates: list[Path] = []
    seen: set[str] = set()
    for raw in paths:
        if not raw:
            continue
        try:
            path = Path(raw).expanduser()
            candidate = path if path.is_dir() else path.parent
            resolved = str(candidate.resolve())
        except Exception:
            continue
        if resolved not in seen:
            seen.add(resolved)
            candidates.append(Path(resolved))
    return candidates


def _verification_snapshot(
    *,
    session_id: str | None,
    changed_paths: list[str],
) -> tuple[dict[str, Any], dict[str, Any]] | None:
    """Return ``(status, facts)`` for the first edited workspace needing proof."""
    try:
        from agent.coding_context import project_facts_for
        from agent.verification_evidence import verification_status
    except Exception:
        return None

    first_snapshot: tuple[dict[str, Any], dict[str, Any]] | None = None
    for cwd in _candidate_cwds(changed_paths):
        facts = project_facts_for(cwd)
        if not facts:
            continue
        status = verification_status(session_id=session_id, cwd=cwd)
        snapshot = (status, facts)
        if first_snapshot is None:
            first_snapshot = snapshot
        if str(status.get("status") or "unverified") != "passed":
            return snapshot
    return first_snapshot


def _format_changed_paths(paths: list[str]) -> str:
    shown = paths[:_MAX_CHANGED_PATHS_IN_NUDGE]
    lines = [f"- `{path}`" for path in shown]
    remaining = len(paths) - len(shown)
    if remaining > 0:
        lines.append(f"- ... and {remaining} more")
    return "\n".join(lines)


def _status_detail(status: dict[str, Any]) -> str:
    state = str(status.get("status") or "unverified")
    evidence = status.get("evidence") if isinstance(status.get("evidence"), dict) else None
    if not evidence:
        return state

    command = evidence.get("canonical_command") or evidence.get("command")
    summary = str(evidence.get("output_summary") or "").strip()
    parts = [state]
    if command:
        parts.append(f"last command `{command}`")
    if summary:
        max_summary = 1200
        if len(summary) > max_summary:
            summary = summary[:max_summary].rstrip() + "\n... [truncated]"
        parts.append(f"last output:\n{summary}")
    return "\n".join(parts)


def build_verify_on_stop_nudge(
    *,
    session_id: str | None,
    changed_paths: Iterable[str],
    attempts: int = 0,
    max_attempts: int = 2,
) -> str | None:
    """Return a synthetic follow-up when edited code lacks fresh verification."""
    # Drop documentation/prose paths (markdown, skills, README, LICENSE, ...) —
    # they carry no verifiable behavior, so a turn that touched only those has
    # nothing to verify and must not nudge.
    paths = sorted({str(p) for p in _filter_verifiable_paths(changed_paths)})
    if not paths or attempts >= max_attempts:
        return None

    snapshot = _verification_snapshot(session_id=session_id, changed_paths=paths)
    if snapshot is None:
        return None
    status, facts = snapshot

    verify_commands = [
        str(cmd).strip()
        for cmd in (facts.get("verifyCommands") or [])
        if str(cmd).strip()
    ]

    state = str(status.get("status") or "unverified")
    if state == "passed":
        return None

    # Optional shipped coding guidance, only paid when this evidence gate fires.
    try:
        from agent.verify_hooks import coding_verify_guidance

        guidance = coding_verify_guidance()
    except Exception:
        guidance = None
    addendum = f"\n\n{guidance}" if guidance else ""

    if verify_commands:
        command_instruction = (
            "Run the relevant verification command now ("
            + ", ".join(f"`{cmd}`" for cmd in verify_commands[:3])
            + (", ..." if len(verify_commands) > 3 else "")
            + "), read any failure, repair the code, and summarize what passed."
        )
    else:
        temp_dir = tempfile.gettempdir()
        command_instruction = (
            "No canonical test/lint/build command was detected. Create a focused "
            f"temporary verification script under `{temp_dir}` using an OS-safe "
            "`tempfile` path with a `hermes-verify-` filename prefix, run it "
            "against the changed behavior, clean it up when possible, and "
            "summarize it explicitly as ad-hoc verification rather than suite "
            "green."
        )

    return (
        "[System: You edited code in this turn, but the workspace does not have "
        "fresh passing verification evidence yet.\n\n"
        f"Verification status: {_status_detail(status)}\n\n"
        f"Changed paths:\n{_format_changed_paths(paths)}\n\n"
        f"{command_instruction} If verification is not possible, explain the "
        "concrete blocker instead of claiming the work is fully verified."
        f"{addendum}]"
    )


__all__ = ["build_verify_on_stop_nudge", "verify_on_stop_enabled"]