from __future__ import annotations

import re
from typing import Any

from yuxi.channels.models import ChannelResponse

from . import cards

_MAX_TEXT_CHARS = 4000


def format_outbound(response: ChannelResponse) -> dict[str, Any]:
    body: dict[str, Any] = {}
    content = sanitize_text(response.content or "")
    if not content:
        content = " "
    body["text"] = _truncate_text(content)

    body = _apply_card(body, response)

    if response.attachments:
        for att in response.attachments:
            if att.url and att.type in ("image", "IMAGE", "video", "VIDEO"):
                body.setdefault("cards_v2", [])
                body["cards_v2"].append({"card": {"sections": [{"widgets": [{"image": {"imageUrl": att.url}}]}]}})

    if response.metadata and response.metadata.get("thread_key"):
        body["messageReplyOption"] = "REPLY_MESSAGE_FALLBACK_TO_NEW_THREAD"
        body["thread"] = {"threadKey": response.metadata["thread_key"]}

    if response.metadata and response.metadata.get("silent"):
        body["disableNotification"] = True

    return body


def _apply_card(body: dict[str, Any], response: ChannelResponse) -> dict[str, Any]:
    if response.metadata and response.metadata.get("card"):
        body["cards_v2"] = response.metadata["card"].get("cards_v2", [])
        return body

    card_type = (response.metadata or {}).get("card_type", "")
    if not card_type:
        return body

    card_params = (response.metadata or {}).get("card_params", {})
    card_body = _build_card(card_type, response.content, card_params)
    if card_body:
        body["cards_v2"] = card_body.get("cards_v2", [])

    return body


def _build_card(card_type: str, content: str, params: dict[str, Any]) -> dict | None:
    action_id = params.get("action_id", "card_action")

    if card_type == "approval":
        return cards.build_approval_card(
            title=params.get("title", content or "审批"),
            action_id=action_id,
            confirm_text=params.get("confirm_text", "确认"),
            reject_text=params.get("reject_text", "拒绝"),
        )

    if card_type == "poll":
        options = params.get("options", [])
        if not options:
            return None
        return cards.build_poll_card(
            question=params.get("title", content or "投票"),
            options=options,
            action_id=action_id,
        )

    if card_type == "info":
        fields = params.get("fields", {})
        if not fields:
            return None
        return cards.build_info_card(
            title=params.get("title", content or "信息"),
            fields=fields,
        )

    if card_type == "form":
        fields = params.get("fields", [])
        if not fields:
            return None
        return cards.build_form_card(
            title=params.get("title", content or "表单"),
            fields=fields,
            submit_action=params.get("submit_action", action_id),
        )

    if card_type == "selection":
        options = params.get("options", [])
        if not options:
            return None
        return cards.build_selection_card(
            title=params.get("title", content or "选择"),
            selection_name=params.get("selection_name", "selection"),
            label=params.get("label", "请选择"),
            options=options,
            selection_type=params.get("selection_type", "SINGLE_SELECT"),
            submit_action=params.get("submit_action"),
        )

    if card_type == "exec_approval":
        return cards.build_exec_approval_card(
            title=params.get("title", content or "执行审批"),
            action_id=action_id,
            detail_fields=params.get("detail_fields"),
        )

    return None


def resolve_reply_to_mode(config: dict | None = None, default: str = "off") -> str:
    if not config:
        return default
    mode = str(config.get("reply_to_mode", config.get("replyToMode", default))).strip().lower()
    if mode in ("first", "all", "off"):
        return mode
    return default


def sanitize_text(text: str) -> str:
    text = text.replace("\x00", "").rstrip()
    text = re.sub(r"[\x00-\x08\x0b\x0c\x0e-\x1f]", "", text)
    return text


def chunk_text_for_outbound(text: str, chunk_limit: int = _MAX_TEXT_CHARS) -> list[str]:
    if not text:
        return []
    if len(text) <= chunk_limit:
        return [text]

    chunks: list[str] = []
    remaining = text

    while remaining:
        if len(remaining) <= chunk_limit:
            chunks.append(remaining)
            break

        split_at = _find_split_point(remaining, chunk_limit)
        chunk = remaining[:split_at].rstrip()
        chunks.append(chunk)
        remaining = remaining[split_at:].lstrip()

    return chunks


def _find_split_point(text: str, limit: int) -> int:
    window = text[:limit]

    code_block_match = re.search(r"```[\s\S]*?```", window)
    if code_block_match and code_block_match.end() <= limit:
        after_end = code_block_match.end()
        if after_end < limit:
            return after_end

    open_fence = re.search(r"```\w*\n", window)
    if open_fence:
        fence_start = open_fence.start()
        closing = text.find("```", fence_start + 3)
        if fence_start > 0 and (closing == -1 or closing >= limit):
            return fence_start

    for pat in [r"\n\n", r"\n", r"\. ", r"。", r"\.\n"]:
        matches = list(re.finditer(pat, window))
        if matches:
            last = matches[-1]
            boundary = last.end()
            if boundary > limit * 0.6:
                return boundary

    for pat_word in [r"\s", r"[,，;；:：!！?？]"]:
        m = re.search(pat_word + r"[^\s]*$", window)
        if m:
            return m.start()

    return limit


def _truncate_text(text: str) -> str:
    if len(text) <= _MAX_TEXT_CHARS:
        return text

    truncated = text[: _MAX_TEXT_CHARS - 3]

    markdown_boundary = _find_markdown_break(truncated)
    if markdown_boundary > _MAX_TEXT_CHARS * 0.8:
        truncated = truncated[:markdown_boundary].rstrip()

    return truncated + "..."


def _find_markdown_break(text: str) -> int:
    best = 0
    for pat in [r"\n\n", r"\n", r"\. ", r"。"]:
        matches = list(re.finditer(pat, text))
        if matches:
            best = matches[-1].end()
            break
    return best if best > 0 else len(text)