from __future__ import annotations

import re
from typing import Any

from .classify import SECTION_ORDER
from .models import NewsItem
from .validate import validate_markdown


END_PUNCTUATION = "。！？；.!?;"


def _clean_text(text: str) -> str:
    value = re.sub(r"^```(?:\w+)?\s*\n?", "", (text or "").strip())
    value = re.sub(r"\n?```\s*$", "", value)
    value = re.sub(r"^\s*>\s*", "", value)
    value = re.sub(r"\[\d+\]|\[N\]", "", value)
    value = re.sub(r"主线判断[：:]\s*", "", value)
    value = re.sub(r"\s+", " ", value).strip()
    return value


def _ensure_sentence(text: str) -> str:
    value = _clean_text(text)
    if value and value[-1] not in END_PUNCTUATION:
        value += "。"
    return value


def _source_link(item: NewsItem) -> str:
    source = item.source_label or item.source_group or "来源"
    if item.url:
        return f"[{source} ↗]({item.url})"
    return source


def _fallback_intro(items: list[NewsItem]) -> str:
    count = len(items)
    return f"今天共聚合 {count} 条 AI 动态，覆盖模型能力、产品应用、基础设施、资本与治理等方向。"


def _fallback_conclusion(items: list[NewsItem]) -> str:
    sections = [section for section in SECTION_ORDER if any(item.section == section for item in items)]
    if sections:
        return "总体看，今日 AI 动态主要集中在" + "、".join(sections[:4]) + "等方向，后续仍需持续观察落地进展。"
    return "总体看，今日 AI 动态仍在持续演进，后续需要关注产品落地和生态变化。"


def assemble_markdown(items: list[NewsItem], guide: dict[str, Any] | None = None) -> tuple[str, dict[str, Any]]:
    guide = guide or {"intro": "", "theme": "", "threads": [], "conclusion": ""}
    lines: list[str] = []

    intro = _ensure_sentence(str(guide.get("intro") or "")) or _fallback_intro(items)
    lines.extend(["## 引言", "", f"> {intro}", ""])

    item_number = 1
    for section in SECTION_ORDER:
        section_items = [item for item in items if item.section == section]
        if not section_items:
            continue
        lines.extend([f"## {section}", ""])
        for item in section_items:
            title = _clean_text(item.title or item.title_raw)
            summary = _ensure_sentence(item.summary or item.summary_raw or "该条目暂无摘要。")
            lines.extend(
                [
                    f"**{item_number}. {title}**",
                    "",
                    f"> {summary}{_source_link(item)}",
                    "",
                ]
            )
            item_number += 1

    threads = guide.get("threads", []) or []
    if threads:
        lines.extend(["## 今日脉络", ""])
        for thread in threads:
            title = _clean_text(str(thread.get("title") or ""))
            text = _ensure_sentence(str(thread.get("text") or ""))
            if not title or not text:
                continue
            lines.extend([f"- **{title}**", f"  {text}", ""])

    conclusion = _ensure_sentence(str(guide.get("conclusion") or "")) or _fallback_conclusion(items)
    lines.extend(["## 总结", "", f"> {conclusion}", ""])

    markdown = "\n".join(lines).strip()
    report = validate_markdown(markdown, items)
    return markdown, report