"""Slack API utilities."""

from __future__ import annotations

import asyncio
import hashlib
import hmac
import logging
import os
import random
import re
import time
from dataclasses import dataclass
from typing import Any
from urllib.parse import urlparse

import httpx

from agent.utils.langsmith import get_langsmith_trace_url

logger = logging.getLogger(__name__)

SLACK_API_BASE_URL = "https://slack.com/api"
SLACK_BOT_TOKEN = os.environ.get("SLACK_BOT_TOKEN", "")
GITHUB_PR_URL_RE = re.compile(r"https?://(?:www\.)?github\.com/[^\s<>|]+/[^\s<>|]+/pull/\d+")
URL_RE = re.compile(r"https?://[^\s<>|]+")


def _is_slack_assistants_api_enabled() -> bool:
    """Whether the Slack Assistants API integration is enabled.

    Read at call time so tests and runtime can toggle via env without reimports.
    """
    return os.environ.get("SLACK_ASSISTANTS_API_ENABLED", "").lower() in {"1", "true", "yes"}


DEFAULT_ASSISTANT_STATUS = "is thinking…"

# Curated rotating loading strings shown by Slack while the indicator is active.
# Capped at 10 by Slack's API.
DEFAULT_LOADING_MESSAGES: tuple[str, ...] = (
    "Pondering…",
    "Cogitating…",
    "Ruminating…",
    "Noodling…",
    "Percolating…",
    "Marinating…",
    "Simmering…",
    "Conjuring…",
    "Tinkering…",
    "Schlepping…",
)


@dataclass(frozen=True)
class GitHubPrRef:
    owner: str
    repo: str
    number: int
    url: str


def _slack_headers() -> dict[str, str]:
    if not SLACK_BOT_TOKEN:
        return {}
    return {
        "Authorization": f"Bearer {SLACK_BOT_TOKEN}",
        "Content-Type": "application/json; charset=utf-8",
    }


def _parse_ts(ts: str | None) -> float:
    try:
        return float(ts or "0")
    except (TypeError, ValueError):
        return 0.0


def _extract_slack_user_name(user: dict[str, Any]) -> str:
    profile = user.get("profile", {})
    if isinstance(profile, dict):
        display_name = profile.get("display_name")
        if isinstance(display_name, str) and display_name.strip():
            return display_name.strip()
        real_name = profile.get("real_name")
        if isinstance(real_name, str) and real_name.strip():
            return real_name.strip()

    real_name = user.get("real_name")
    if isinstance(real_name, str) and real_name.strip():
        return real_name.strip()

    name = user.get("name")
    if isinstance(name, str) and name.strip():
        return name.strip()

    return "unknown"


def replace_bot_mention_with_username(text: str, bot_user_id: str, bot_username: str) -> str:
    """Replace Slack bot ID mention token with @username."""
    if not text:
        return ""
    if bot_user_id and bot_username:
        return text.replace(f"<@{bot_user_id}>", f"@{bot_username}")
    return text


def convert_mentions_to_slack_format(text: str) -> str:
    """Convert @Name(USER_ID) patterns to Slack's <@USER_ID> mention format."""
    return re.sub(r"@[^()]+\(([A-Z0-9]+)\)", r"<@\1>", text)


def verify_slack_signature(
    body: bytes,
    timestamp: str,
    signature: str,
    secret: str,
    max_age_seconds: int = 300,
) -> bool:
    """Verify Slack request signature."""
    if not secret:
        logger.warning("SLACK_SIGNING_SECRET is not configured — rejecting webhook request")
        return False
    if not timestamp or not signature:
        return False
    try:
        request_timestamp = int(timestamp)
    except ValueError:
        return False
    if abs(int(time.time()) - request_timestamp) > max_age_seconds:
        return False

    base_string = f"v0:{timestamp}:{body.decode('utf-8', errors='replace')}"
    expected = (
        "v0="
        + hmac.new(secret.encode("utf-8"), base_string.encode("utf-8"), hashlib.sha256).hexdigest()
    )
    return hmac.compare_digest(expected, signature)


def strip_bot_mention(text: str, bot_user_id: str, bot_username: str = "") -> str:
    """Remove bot mention token from Slack text."""
    if not text:
        return ""
    stripped = text
    if bot_user_id:
        stripped = stripped.replace(f"<@{bot_user_id}>", "")
    if bot_username:
        stripped = stripped.replace(f"@{bot_username}", "")
    return stripped.strip()


def parse_github_pr_url(url: str) -> GitHubPrRef | None:
    cleaned_url = url.strip().strip("<>")
    if "|" in cleaned_url:
        cleaned_url = cleaned_url.split("|", 1)[0]

    parsed = urlparse(cleaned_url)
    if parsed.scheme not in {"http", "https"}:
        return None
    if parsed.netloc.lower() not in {"github.com", "www.github.com"}:
        return None

    path_parts = [part for part in parsed.path.split("/") if part]
    if len(path_parts) < 4 or path_parts[2] != "pull":
        return None

    try:
        number = int(path_parts[3])
    except ValueError:
        return None

    owner = path_parts[0]
    repo = path_parts[1]
    return GitHubPrRef(
        owner=owner,
        repo=repo,
        number=number,
        url=f"https://github.com/{owner}/{repo}/pull/{number}",
    )


def parse_slack_review_command(text: str) -> GitHubPrRef | None:
    stripped = text.strip()
    command_match = re.fullmatch(r"(?is)review\s+(.+)", stripped)
    if not command_match:
        return None

    rest = command_match.group(1).strip()
    url_match = GITHUB_PR_URL_RE.search(rest)
    if not url_match:
        return None

    trailing_text = rest[url_match.end() :].strip()
    if trailing_text and trailing_text != ">" and not trailing_text.startswith("|"):
        return None

    return parse_github_pr_url(url_match.group(0))


def looks_like_slack_pr_review_command(text: str) -> bool:
    stripped = text.strip()
    if not re.match(r"(?is)^review\b", stripped):
        return False
    for match in URL_RE.finditer(stripped):
        parsed = urlparse(match.group(0).strip("<>"))
        host = (parsed.hostname or "").lower()
        if parsed.scheme in {"http", "https"} and host in {"github.com", "www.github.com"}:
            return True
    return False


def select_slack_context_messages(
    messages: list[dict[str, Any]],
    current_message_ts: str,
    bot_user_id: str,
    bot_username: str = "",
) -> tuple[list[dict[str, Any]], str]:
    """Select context from thread start or previous bot mention."""
    if not messages:
        return [], "thread_start"

    current_ts = _parse_ts(current_message_ts)
    ordered = sorted(messages, key=lambda item: _parse_ts(item.get("ts")))
    up_to_current = [item for item in ordered if _parse_ts(item.get("ts")) <= current_ts]
    if not up_to_current:
        up_to_current = ordered

    mention_tokens = []
    if bot_user_id:
        mention_tokens.append(f"<@{bot_user_id}>")
    if bot_username:
        mention_tokens.append(f"@{bot_username}")
    if not mention_tokens:
        return up_to_current, "thread_start"

    last_mention_index = -1
    for index, message in enumerate(up_to_current[:-1]):
        text = message.get("text", "")
        if isinstance(text, str) and any(token in text for token in mention_tokens):
            last_mention_index = index

    if last_mention_index >= 0:
        return up_to_current[last_mention_index:], "last_mention"
    return up_to_current, "thread_start"


def format_slack_messages_for_prompt(
    messages: list[dict[str, Any]],
    user_names_by_id: dict[str, str] | None = None,
    bot_user_id: str = "",
    bot_username: str = "",
) -> str:
    """Format Slack messages into readable prompt text."""
    if not messages:
        return "(no thread messages available)"

    lines: list[str] = []
    for message in messages:
        text = (
            replace_bot_mention_with_username(
                str(message.get("text", "")),
                bot_user_id=bot_user_id,
                bot_username=bot_username,
            ).strip()
            or "[non-text message]"
        )
        user_id = message.get("user")
        if isinstance(user_id, str) and user_id:
            author_name = (user_names_by_id or {}).get(user_id) or user_id
            author = f"@{author_name}({user_id})"
        else:
            bot_profile = message.get("bot_profile", {})
            if isinstance(bot_profile, dict):
                bot_name = bot_profile.get("name") or message.get("username") or "Bot"
            else:
                bot_name = message.get("username") or "Bot"
            author = f"@{bot_name}(bot)"
        lines.append(f"{author}: {text}")
    return "\n".join(lines)


async def set_slack_assistant_status(
    channel_id: str,
    thread_ts: str,
    status: str = DEFAULT_ASSISTANT_STATUS,
    loading_messages: list[str] | tuple[str, ...] | None = None,
) -> bool:
    """Set the assistant typing/status indicator on a Slack thread.

    Wraps Slack's `assistant.threads.setStatus` API. The `chat:write` scope
    on the bot token is sufficient. Status auto-clears when the bot posts to
    the thread, and Slack itself expires it after ~2 minutes — callers that
    want it visible across longer runs must refresh it periodically.

    `loading_messages` is an optional list (max 10) of strings Slack rotates
    through while the indicator is visible.

    No-op (returning False) when the assistants feature flag is disabled,
    the bot token is missing, or the channel/thread is not provided.
    Failures are logged but never raised — the indicator is a UX nicety,
    not a correctness requirement.
    """
    if not _is_slack_assistants_api_enabled():
        return False
    if not SLACK_BOT_TOKEN or not channel_id or not thread_ts:
        return False

    payload: dict[str, Any] = {
        "channel_id": channel_id,
        "thread_ts": thread_ts,
        "status": status,
    }
    if loading_messages:
        payload["loading_messages"] = list(loading_messages)[:10]

    async with httpx.AsyncClient() as http_client:
        try:
            response = await http_client.post(
                f"{SLACK_API_BASE_URL}/assistant.threads.setStatus",
                headers=_slack_headers(),
                json=payload,
            )
            response.raise_for_status()
            data = response.json()
            if not data.get("ok"):
                logger.warning("Slack assistant.threads.setStatus failed: %s", data.get("error"))
                return False
            return True
        except httpx.HTTPError:
            logger.exception("Slack assistant.threads.setStatus request failed")
            return False


async def post_slack_thread_reply(channel_id: str, thread_ts: str, text: str) -> bool:
    """Post a reply in a Slack thread."""
    if not SLACK_BOT_TOKEN:
        return False

    payload = {
        "channel": channel_id,
        "thread_ts": thread_ts,
        "text": text,
    }

    async with httpx.AsyncClient() as http_client:
        try:
            response = await http_client.post(
                f"{SLACK_API_BASE_URL}/chat.postMessage",
                headers=_slack_headers(),
                json=payload,
            )
            response.raise_for_status()
            data = response.json()
            if not data.get("ok"):
                logger.warning("Slack chat.postMessage failed: %s", data.get("error"))
                return False
            return True
        except httpx.HTTPError:
            logger.exception("Slack chat.postMessage request failed")
            return False


async def post_slack_ephemeral_message(
    channel_id: str, user_id: str, text: str, thread_ts: str | None = None
) -> bool:
    """Post an ephemeral message visible only to one user."""
    if not SLACK_BOT_TOKEN:
        return False

    payload: dict[str, str] = {
        "channel": channel_id,
        "user": user_id,
        "text": text,
    }
    if thread_ts:
        payload["thread_ts"] = thread_ts

    async with httpx.AsyncClient() as http_client:
        try:
            response = await http_client.post(
                f"{SLACK_API_BASE_URL}/chat.postEphemeral",
                headers=_slack_headers(),
                json=payload,
            )
            response.raise_for_status()
            data = response.json()
            if not data.get("ok"):
                logger.warning("Slack chat.postEphemeral failed: %s", data.get("error"))
                return False
            return True
        except httpx.HTTPError:
            logger.exception("Slack chat.postEphemeral request failed")
            return False


async def add_slack_reaction(channel_id: str, message_ts: str, emoji: str = "eyes") -> bool:
    """Add a reaction to a Slack message."""
    if not SLACK_BOT_TOKEN:
        return False

    payload = {
        "channel": channel_id,
        "timestamp": message_ts,
        "name": emoji,
    }

    async with httpx.AsyncClient() as http_client:
        try:
            response = await http_client.post(
                f"{SLACK_API_BASE_URL}/reactions.add",
                headers=_slack_headers(),
                json=payload,
            )
            response.raise_for_status()
            data = response.json()
            if data.get("ok"):
                return True
            if data.get("error") == "already_reacted":
                return True
            logger.warning("Slack reactions.add failed: %s", data.get("error"))
            return False
        except httpx.HTTPError:
            logger.exception("Slack reactions.add request failed")
            return False


async def get_slack_user_info(user_id: str) -> dict[str, Any] | None:
    """Get Slack user details by user ID."""
    if not SLACK_BOT_TOKEN:
        return None

    async with httpx.AsyncClient() as http_client:
        try:
            response = await http_client.get(
                f"{SLACK_API_BASE_URL}/users.info",
                headers=_slack_headers(),
                params={"user": user_id},
            )
            response.raise_for_status()
            data = response.json()
            if not data.get("ok"):
                logger.warning("Slack users.info failed: %s", data.get("error"))
                return None
            user = data.get("user")
            if isinstance(user, dict):
                return user
        except httpx.HTTPError:
            logger.exception("Slack users.info request failed")
    return None


async def get_slack_user_names(user_ids: list[str]) -> dict[str, str]:
    """Get display names for a set of Slack user IDs."""
    unique_ids = sorted({user_id for user_id in user_ids if isinstance(user_id, str) and user_id})
    if not unique_ids:
        return {}

    user_infos = await asyncio.gather(
        *(get_slack_user_info(user_id) for user_id in unique_ids),
        return_exceptions=True,
    )

    user_names: dict[str, str] = {}
    for user_id, user_info in zip(unique_ids, user_infos, strict=True):
        if isinstance(user_info, dict):
            user_names[user_id] = _extract_slack_user_name(user_info)
        else:
            user_names[user_id] = user_id
    return user_names


async def fetch_slack_thread_messages(channel_id: str, thread_ts: str) -> list[dict[str, Any]]:
    """Fetch all messages for a Slack thread."""
    if not SLACK_BOT_TOKEN:
        return []

    messages: list[dict[str, Any]] = []
    cursor: str | None = None

    async with httpx.AsyncClient() as http_client:
        while True:
            params: dict[str, str | int] = {"channel": channel_id, "ts": thread_ts, "limit": 200}
            if cursor:
                params["cursor"] = cursor

            try:
                response = await http_client.get(
                    f"{SLACK_API_BASE_URL}/conversations.replies",
                    headers=_slack_headers(),
                    params=params,
                )
                response.raise_for_status()
                payload = response.json()
            except httpx.HTTPError:
                logger.exception("Slack conversations.replies request failed")
                break

            if not payload.get("ok"):
                logger.warning("Slack conversations.replies failed: %s", payload.get("error"))
                break

            batch = payload.get("messages", [])
            if isinstance(batch, list):
                messages.extend(item for item in batch if isinstance(item, dict))

            response_metadata = payload.get("response_metadata", {})
            cursor = (
                response_metadata.get("next_cursor") if isinstance(response_metadata, dict) else ""
            )
            if not cursor:
                break

    messages.sort(key=lambda item: _parse_ts(item.get("ts")))
    return messages


SLACK_MESSAGE_URL_RE = re.compile(
    r"https?://[a-zA-Z0-9\-]+\.slack\.com/archives/([A-Za-z0-9]+)/p(\d{16})(?:\?[^\s>]*)?"
)


def parse_slack_message_url(url: str) -> tuple[str, str] | None:
    """Parse a Slack message URL into (channel_id, message_ts).

    URL format: https://{workspace}.slack.com/archives/{channel_id}/p{ts_without_dot}
    The 16-digit timestamp becomes {first_10}.{last_6} (e.g. p1776281321762829 -> 1776281321.762829).
    """
    match = SLACK_MESSAGE_URL_RE.search(url)
    if not match:
        return None
    channel_id = match.group(1)
    raw_ts = match.group(2)
    message_ts = f"{raw_ts[:10]}.{raw_ts[10:]}"
    return channel_id, message_ts


def extract_slack_message_urls(text: str) -> list[tuple[str, str, str]]:
    """Extract all Slack message URLs from text.

    Returns list of (full_url, channel_id, message_ts) tuples.
    """
    results: list[tuple[str, str, str]] = []
    for match in SLACK_MESSAGE_URL_RE.finditer(text):
        full_url = match.group(0)
        parsed = parse_slack_message_url(full_url)
        if parsed:
            results.append((full_url, parsed[0], parsed[1]))
    return results


async def fetch_slack_message_by_ts(channel_id: str, message_ts: str) -> dict[str, Any] | None:
    """Fetch a single Slack message by channel and timestamp."""
    if not SLACK_BOT_TOKEN:
        return None

    async with httpx.AsyncClient() as http_client:
        try:
            response = await http_client.get(
                f"{SLACK_API_BASE_URL}/conversations.history",
                headers=_slack_headers(),
                params={
                    "channel": channel_id,
                    "latest": message_ts,
                    "oldest": message_ts,
                    "inclusive": "true",
                    "limit": 1,
                },
            )
            response.raise_for_status()
            data = response.json()
            if not data.get("ok"):
                logger.warning(
                    "Slack conversations.history failed for channel=%s ts=%s: %s",
                    channel_id,
                    message_ts,
                    data.get("error"),
                )
                return None
            messages = data.get("messages", [])
            if messages and isinstance(messages[0], dict):
                return messages[0]
        except httpx.HTTPError:
            logger.exception(
                "Slack conversations.history request failed for channel=%s ts=%s",
                channel_id,
                message_ts,
            )
    return None


async def resolve_slack_message_url(url: str) -> dict[str, Any] | None:
    """Resolve a Slack message URL to its message content.

    Returns a dict with keys: text, user, ts, channel_id, files, thread_ts (if threaded).
    """
    parsed = parse_slack_message_url(url)
    if not parsed:
        return None

    channel_id, message_ts = parsed
    message = await fetch_slack_message_by_ts(channel_id, message_ts)
    if not message:
        return None

    result: dict[str, Any] = {
        "channel_id": channel_id,
        "ts": message.get("ts", message_ts),
        "text": message.get("text", ""),
        "user": message.get("user", ""),
        "files": message.get("files", []),
    }
    if message.get("thread_ts"):
        result["thread_ts"] = message["thread_ts"]
    return result


async def resolve_slack_links_in_context(
    context_messages: list[dict[str, Any]],
    user_names_by_id: dict[str, str],
) -> tuple[str, list[str]]:
    """Resolve cross-posted Slack message links found in context messages.

    Returns (resolved_links_section, image_urls) where resolved_links_section
    is a formatted markdown string for the prompt, and image_urls is a list
    of image URLs from resolved message attachments.
    """
    all_context_text = " ".join(msg.get("text", "") for msg in context_messages)
    slack_links = extract_slack_message_urls(all_context_text)
    if not slack_links:
        return "", []

    resolved_parts: list[str] = []
    image_urls: list[str] = []
    seen_urls: set[str] = set()

    for link_url, _cid, _ts in slack_links:
        if link_url in seen_urls:
            continue
        seen_urls.add(link_url)
        try:
            resolved = await resolve_slack_message_url(link_url)
            if resolved:
                author_id = resolved.get("user", "")
                author = user_names_by_id.get(author_id, author_id)
                if author_id and author == author_id:
                    extra_names = await get_slack_user_names([author_id])
                    author = extra_names.get(author_id, author_id)
                resolved_text = resolved.get("text", "(empty message)")
                resolved_parts.append(
                    f"**{link_url}**\n  Author: {author}\n  Message: {resolved_text}"
                )
                for file_info in resolved.get("files", []):
                    if (
                        isinstance(file_info, dict)
                        and file_info.get("mimetype", "").startswith("image/")
                        and file_info.get("url_private")
                    ):
                        image_urls.append(file_info["url_private"])
            else:
                resolved_parts.append(
                    f"**{link_url}**\n  (Could not fetch — bot may not have access)"
                )
        except Exception:
            logger.exception("Failed to resolve Slack link %s", link_url)
            resolved_parts.append(f"**{link_url}**\n  (Error resolving link)")

    resolved_links_section = ""
    if resolved_parts:
        resolved_links_section = "\n\n## Cross-posted Slack Messages\n" + "\n\n".join(
            resolved_parts
        )

    return resolved_links_section, image_urls


TRACE_REPLY_PHRASES: tuple[str, ...] = (
    "Working on it!",
    "On it!",
    "Diving in!",
    "Powering up!",
    "Heads down.",
    "Cracking knuckles...",
    "Spinning up...",
    "Looking...",
    "Time to cook. 🧑‍🍳",
    "Running to the roar!",
)

TRACE_REPLY_TIPS: tuple[str, ...] = (
    "You can message me in this thread while I'm running — I'll pick up your follow-up before my next step.",
    "Kick off another task in parallel — each one runs in its own isolated sandbox, no queuing.",
    "Add `repo:owner/name` to your message to point me at a different repo for this task.",
    "Drop an `AGENTS.md` at your repo root and I'll read it on every run — it's the easiest way to teach me your conventions.",
    "I'll open a draft PR automatically when I'm done and link it back here.",
    "Tag me on a PR comment of an open-swe PR to have me address review feedback on the same branch.",
    "I can spawn subagents for independent subtasks — useful for parallel research or fan-out work.",
    "Click `View trace` above to watch every tool call and model response live in LangSmith.",
)


def _format_trace_reply(message: str, trace_url: str | None) -> str:
    """Format the initial trace reply with a randomly selected tip."""
    tip = random.choice(TRACE_REPLY_TIPS)
    head = f"{message} <{trace_url}|View trace>" if trace_url else message
    return f"{head}\n_Tip: {tip}_"


async def post_slack_trace_reply(
    channel_id: str, thread_ts: str, thread_id: str, message: str | None = None
) -> None:
    """Post a trace URL reply in a Slack thread."""
    if message is None:
        message = random.choice(TRACE_REPLY_PHRASES)
    trace_url = get_langsmith_trace_url(thread_id)
    await post_slack_thread_reply(channel_id, thread_ts, _format_trace_reply(message, trace_url))