"""
Transport-agnostic WhatsApp behavior shared by the Baileys bridge adapter and the
Cloud API adapter: allow-list / DM / group gating, mention detection, quoted-reply-
to-bot detection, broadcast filtering, WhatsApp markdown conversion, chunk budgeting.

Mixin contract — the host adapter sets these on ``self`` before calling any mixin
method: ``config`` (PlatformConfig), ``name``, ``_dm_policy`` / ``_group_policy``
("open" | "allowlist" | "disabled" | "pairing"), ``_allow_from`` / ``_group_allow_from`` (set[str]),
``_mention_patterns`` (list[re.Pattern]), ``_reply_prefix`` (Optional[str]).
"""

from __future__ import annotations

import json
import logging
import os
import re
from pathlib import Path
from typing import Any, Dict, Optional

from gateway.platforms._shared import (
    decode_json_list_literal as _decode_json_list_literal, extra_or_secret as _extra_or_wsecret,
    get_scoped_secret as _get_wsecret
)
from gateway.platforms.access_policy_mixin import OwnAccessPolicyMixin


logger = logging.getLogger(__name__)

_TRUTHY = {"true", "1", "yes", "on"}


def _stash(pattern: str, text: str, tag: str) -> tuple[str, list[str]]:
    """Replace every ``pattern`` match with a ``\\x00<tag><n>\\x00`` placeholder."""
    saved: list[str] = []

    def keep(m: re.Match) -> str:
        saved.append(m.group(0))
        return f"\x00{tag}{len(saved) - 1}\x00"

    return re.sub(pattern, keep, text), saved


def _header_to_bold(m: re.Match) -> str:
    """``# Header`` → ``*Header*``, stripping already-bolded ``*...*`` so ``# **Title**``
    doesn't render with literal asterisks."""
    inner = m.group(1).strip()
    while len(inner) > 1 and inner.startswith("*") and inner.endswith("*"):
        inner = inner[1:-1].strip()
    return f"*{inner}*"


class WhatsAppBehaviorMixin(OwnAccessPolicyMixin):
    """Shared behavior for all WhatsApp adapters (Baileys + Cloud API); owns no state
    of its own — see the module docstring for the host adapter's attribute contract."""

    # Practical UX limit, not the ~65K protocol max (long messages are unreadable on mobile).
    MAX_MESSAGE_LENGTH: int = 4096
    ALLOW_ALL_ENV_PREFIX = "WHATSAPP"
    supports_code_blocks = True  # WhatsApp renders fenced code blocks (monospace)

    DEFAULT_REPLY_PREFIX: str = "☤ *Hermes Agent*\n────────────\n"

    _OUTBOUND_INVISIBLE_CHARS_RE = re.compile(r"[\u200b\u2060\u2063\ufeff]")
    _OUTBOUND_ODD_SPACE_RE = re.compile(r"[\u00a0\u1680\u180e\u2000-\u200a\u202f\u205f\u3000]")

    @classmethod
    def _sanitize_outbound_text(cls, content: str) -> str:
        """Strip zero-width format chars (WORD JOINER etc.) and normalize odd unicode
        spaces — WhatsApp renders them as mojibake prefixes. Emoji joiners are kept."""
        if not content:
            return content
        return cls._OUTBOUND_ODD_SPACE_RE.sub(" ", cls._OUTBOUND_INVISIBLE_CHARS_RE.sub("", content))

    def _effective_reply_prefix(self) -> str:
        """Prefix for outgoing replies in self-chat mode (Cloud API overrides to ``""``)."""
        if (_get_wsecret("WHATSAPP_MODE", default="self-chat") or "self-chat") != "self-chat":
            return ""
        if self._reply_prefix is not None:
            return self._reply_prefix.replace("\\n", "\n")
        env_prefix = _get_wsecret("WHATSAPP_REPLY_PREFIX")
        if env_prefix is not None:
            return env_prefix.replace("\\n", "\n")
        return self.DEFAULT_REPLY_PREFIX

    def _outgoing_chunk_limit(self) -> int:
        """Reserve room for the reply prefix; floor keeps space for pagination/fence repair."""
        return max(1024, self.MAX_MESSAGE_LENGTH - len(self._effective_reply_prefix()))

    def _whatsapp_require_mention(self) -> bool:
        configured = self.config.extra.get("require_mention")
        if configured is None:
            configured = _get_wsecret("WHATSAPP_REQUIRE_MENTION", default="false") or "false"
        if isinstance(configured, str):
            return configured.lower() in _TRUTHY
        return bool(configured)

    def _whatsapp_free_response_chats(self) -> set[str]:
        """``extra.free_response_chats`` (blank = unset) else the scoped env CSV."""
        return self._coerce_allow_list(
            _extra_or_wsecret(self.config.extra, "free_response_chats", "WHATSAPP_FREE_RESPONSE_CHATS"))

    @staticmethod
    def _coerce_allow_list(raw) -> set[str]:
        """Parse allow_from / group_allow_from from config (list or JSON-list string) or env var (CSV)."""
        if raw is None:
            return set()
        raw = _decode_json_list_literal(raw)
        parts = raw if isinstance(raw, list) else str(raw).split(",")
        return {str(part).strip() for part in parts if str(part).strip()}

    @staticmethod
    def _select_allowlist(extra: Dict[str, Any], config_keys, env_keys, read_env) -> tuple[Optional[str], Any]:
        """``(source, raw)`` by key *presence*: a config key wins (an explicit empty list stays authoritative),
        then the first truthy env carrier; ``(None, None)`` when neither is set."""
        for key in config_keys:
            if key in extra:
                return "config", extra.get(key)
        for env in env_keys:
            raw = read_env(env)
            if raw:
                return env, raw
        return None, None

    def _select_dm_allowlist(self, extra: Dict[str, Any], env_keys, read_env) -> Any:
        """Raw DM allowlist; records the winning source in ``_dm_allowlist_source`` so live DM checks keep
        the same precedence."""
        self._dm_allowlist_source, raw = self._select_allowlist(extra, ("allow_from", "allowFrom"), env_keys, read_env)
        return raw

    def _live_dm_allow_from(self) -> set[str]:
        """Allowlist currently enforced for DM intake / strict DM auth. Env-seeded adapters re-read
        the same key so pairing approve/revoke takes effect without restart; a removed key (sole-entry
        revoke) means empty, not the construction snapshot. Config-seeded adapters keep the in-memory
        set (pairing revoke purges it in place) — a stale env value must not broaden access."""
        source = getattr(self, "_dm_allowlist_source", None)
        if isinstance(source, str) and source != "config":
            # Scoped read: under multiplex os.environ is the DEFAULT profile's allowlist. None = key
            # absent (revoked) → empty, never the construction snapshot.
            live = _get_wsecret(source)
            return self._coerce_allow_list(live) if live is not None else set()
        return set(self._allow_from or ())

    # ------------------------------------------------------------------ JID helpers
    @staticmethod
    def _normalize_whatsapp_id(value: Optional[str]) -> str:
        if not value:
            return ""
        # Device-qualified ids (`<user>:<device>@lid`) must equal their bare form.
        return re.sub(r":\d+(?=@)", "", str(value).strip())

    @staticmethod
    def _is_broadcast_chat(chat_id: str) -> bool:
        """Status updates (Stories) and Channel/Newsletter broadcasts — never reply
        (answering a Story spams the status feed; Channel posts aren't addressable)."""
        cid = (chat_id or "").strip().lower()
        return cid == "status@broadcast" or cid.endswith(("@broadcast", "@newsletter"))

    # ------------------------------------------------------------------ gating
    @staticmethod
    def _matches_whatsapp_allowlist(candidate: str, allow_from) -> bool:
        """Match a WhatsApp identifier against an allowlist across phone/LID forms. Inbound senders
        arrive as ``<id>@lid`` while allowlists hold phone numbers (or vice versa), so resolve both
        sides through the bridge's lid-mapping files via ``gateway.whatsapp_identity``."""
        if not allow_from:
            return False
        if candidate in allow_from:
            return True
        from gateway.whatsapp_identity import expand_whatsapp_aliases, normalize_whatsapp_identifier
        candidate_aliases = expand_whatsapp_aliases(candidate)
        if not candidate_aliases:
            return False
        return any(
            entry == "*"
            or normalize_whatsapp_identifier(entry) in candidate_aliases
            or expand_whatsapp_aliases(entry) & candidate_aliases
            for entry in allow_from
        )

    def _entry_matches(self, entries, target: str) -> bool:
        return self._matches_whatsapp_allowlist(target, entries)

    def _compile_mention_patterns(self):
        patterns = self.config.extra.get("mention_patterns")
        if patterns is None:
            raw = (_get_wsecret("WHATSAPP_MENTION_PATTERNS", default="") or "").strip()
            if raw:
                try:
                    patterns = json.loads(raw)
                except Exception:
                    # Plain text: one pattern per line, else comma-separated.
                    patterns = [p.strip() for p in raw.splitlines() if p.strip()]
                    patterns = patterns or [p.strip() for p in raw.split(",") if p.strip()]
        if patterns is None:
            return []
        if isinstance(patterns, str):
            patterns = [patterns]
        if not isinstance(patterns, list):
            logger.warning("[%s] whatsapp mention_patterns must be a list or string; got %s", self.name, type(patterns).__name__)
            return []
        compiled = []
        for pattern in patterns:
            if not isinstance(pattern, str) or not pattern.strip():
                continue
            try:
                compiled.append(re.compile(pattern, re.IGNORECASE))
            except re.error as exc:
                logger.warning("[%s] Invalid WhatsApp mention pattern %r: %s", self.name, pattern, exc)
        if compiled:
            logger.info("[%s] Loaded %d WhatsApp mention pattern(s)", self.name, len(compiled))
        return compiled

    def _bot_ids_from_message(self, data: Dict[str, Any]) -> set[str]:
        return {nid for c in (data.get("botIds") or []) if (nid := self._normalize_whatsapp_id(c))}

    def _message_is_reply_to_bot(self, data: Dict[str, Any]) -> bool:
        quoted_participant = self._normalize_whatsapp_id(data.get("quotedParticipant"))
        return bool(quoted_participant) and quoted_participant in self._bot_ids_from_message(data)

    def _message_mentions_bot(self, data: Dict[str, Any]) -> bool:
        bot_ids = self._bot_ids_from_message(data)
        if not bot_ids:
            return False
        mentioned = {nid for c in (data.get("mentionedIds") or []) if (nid := self._normalize_whatsapp_id(c))}
        if mentioned & bot_ids:
            return True
        lower_body = str(data.get("body") or "").lower()
        return any(
            bare and (f"@{bare}" in lower_body or bare in lower_body)
            for bare in (bot_id.split("@", 1)[0].lower() for bot_id in bot_ids)
        )

    def _message_matches_mention_patterns(self, data: Dict[str, Any]) -> bool:
        body = str(data.get("body") or "")
        return any(pattern.search(body) for pattern in self._mention_patterns or ())

    def _clean_bot_mention_text(self, text: str, data: Dict[str, Any]) -> str:
        if not text:
            return text
        cleaned = text
        for bot_id in self._bot_ids_from_message(data):
            bare_id = bot_id.split("@", 1)[0]
            if bare_id:
                cleaned = re.sub(rf"@{re.escape(bare_id)}\b[,:\-]*\s*", "", cleaned)
        return cleaned.strip() or text

    def _should_process_message(self, data: Dict[str, Any]) -> bool:
        chat_id = str(data.get("chatId") or "")
        # Broadcast pseudo-chats are filtered even in self-chat mode (fromMe events).
        if self._is_broadcast_chat(chat_id):
            return False
        if not data.get("isGroup", False):
            # DMs that pass the policy gate are always processed
            return self._is_dm_intake_allowed(str(data.get("senderId") or data.get("from") or ""))
        if not self._is_group_allowed(chat_id):
            return False
        # Group messages: check mention / free-response settings
        if chat_id in self._whatsapp_free_response_chats() or not self._whatsapp_require_mention():
            return True
        return (
            str(data.get("body") or "").strip().startswith("/")
            or self._message_is_reply_to_bot(data)
            or self._message_mentions_bot(data)
            or self._message_matches_mention_patterns(data)
        )

    # ------------------------------------------------------------------ formatting
    def format_message(self, content: str) -> str:
        """Convert markdown to WhatsApp syntax (*bold*, _italic_, ~strike~); fenced and
        inline code are protected via placeholder substitution."""
        if not content:
            return content
        result, fences = _stash(r"```[\s\S]*?```", self._sanitize_outbound_text(content), "FENCE")
        result, codes = _stash(r"`[^`\n]+`", result, "CODE")
        # Italic *text* → _text_ BEFORE bold so **bold** doesn't become italic;
        # lookarounds skip list bullets and bold delimiters.
        result = re.sub(r"(?<!\*)\*(?!\s|\*)([^*\n]*?\S[^*\n]*?)\*(?!\*)", r"_\1_", result)
        result = re.sub(r"\*\*(.+?)\*\*", r"*\1*", result)
        result = re.sub(r"__(.+?)__", r"*\1*", result)
        result = re.sub(r"~~(.+?)~~", r"~\1~", result)
        result = re.sub(r"^#{1,6}\s+(.+)$", _header_to_bold, result, flags=re.MULTILINE)
        result = re.sub(r"\[([^\]]+)\]\(([^)]+)\)", r"\1 (\2)", result)  # [text](url) → text (url)
        for tag, saved in (("FENCE", fences), ("CODE", codes)):
            for i, original in enumerate(saved):
                result = result.replace(f"\x00{tag}{i}\x00", original)
        return result


def resolve_whatsapp_bridge_dir() -> Path:
    """Bridge directory for CLI and adapter. A read-only install tree (e.g. Docker
    /opt/hermes) is mirrored to HERMES_HOME so npm install works."""
    import shutil
    from hermes_constants import get_hermes_home
    install_bridge = Path(__file__).resolve().parents[2] / "scripts" / "whatsapp-bridge"
    hermes_home_bridge = get_hermes_home() / "scripts" / "whatsapp-bridge"
    try:
        (install_bridge / ".write_test").touch()
        (install_bridge / ".write_test").unlink()
        return install_bridge
    except OSError:
        pass
    if hermes_home_bridge.exists():
        return hermes_home_bridge
    try:
        hermes_home_bridge.parent.mkdir(parents=True, exist_ok=True)
        shutil.copytree(install_bridge, hermes_home_bridge, dirs_exist_ok=False)
        return hermes_home_bridge
    except Exception:
        return install_bridge