"""节点实现"""
import asyncio
import hashlib

from langchain_core.output_parsers import PydanticOutputParser
from pydantic import BaseModel, Field
from langchain_core.messages import HumanMessage
from src.bash_model import GeneralLlm, AnalyseLlm
from .state import NextPageState
from .prompts import FIND_PAGINATION_AREA_PROMPT, FIND_NEXT_BUTTON_PROMPT


# 结构化输出模型
class SelectorResult(BaseModel):
    """选择器结果"""
    selector: str | None = Field(description="CSS选择器，找不到则为None")
    reason: str = Field(description="选择或找不到的原因")


async def fetch_page(state: NextPageState) -> dict:
    """节点1: 获取页面 HTML"""
    url = state["url"]
    page = state["page"]
    
    print(f"[节点1] 访问页面: {url}")
    
    await page.goto(url, wait_until="load", timeout=60000)
    await asyncio.sleep(3)
    
    # 获取清理后的 HTMLa
    html = await page.evaluate("""
        () => {
            const clone = document.body.cloneNode(true);
            clone.querySelectorAll('style, script, noscript, svg, link').forEach(el => el.remove());
            return clone.innerHTML;
        }
    """)
    
    print(f"[节点1] 获取 HTML 完成，长度: {len(html)}")
    
    return {
        "html": html,
        "failed_selectors": [],
        "retry_count": 0
    }


async def find_pagination_area(state: NextPageState) -> dict:
    """节点2: 找分页区域"""
    html = state["html"]
    page = state["page"]
    
    print("[节点2] 分析分页区域...")
    
    # LLM 分析
    prompt = FIND_PAGINATION_AREA_PROMPT.format(html=html)

    chain = AnalyseLlm | PydanticOutputParser(pydantic_object=SelectorResult)
    result = await chain.ainvoke([HumanMessage(content=prompt)])

    #
    # llm = AnalyseLlm.with_structured_output(SelectorResult)
    # result = await llm.ainvoke([HumanMessage(content=prompt)])
    
    if not result.selector:
        # 无分页控件，直接成功
        print(f"[节点2] 无分页控件: {result.reason}")
        return {
            "has_pagination": 0,
            "is_valid": True
        }
    
    print(f"[节点2] 找到分页区域: {result.selector}")
    
    # 获取区域 HTML
    try:
        pagination_html = await page.inner_html(result.selector)
    except Exception as e:
        # 选择器无效，当作无分页
        print(f"[节点2] 选择器无效: {result.selector}, {e}")
        return {
            "has_pagination": 0,
            "is_valid": True
        }
    
    return {
        "has_pagination": 1,
        "pagination_selector": result.selector,
        "pagination_html": pagination_html
    }


async def find_next_button(state: NextPageState) -> dict:
    """节点3: 找下一页按钮"""
    pagination_html = state["pagination_html"]
    pagination_selector = state["pagination_selector"]
    failed_selectors = state.get("failed_selectors", [])
    retry_count = state.get("retry_count", 0)
    page = state["page"]
    
    print(f"[节点3] 分析下一页按钮... (重试: {retry_count})")
    
    # LLM 分析
    prompt = FIND_NEXT_BUTTON_PROMPT.format(
        pagination_html=pagination_html,
        failed_selectors="\n".join(failed_selectors) if failed_selectors else "无"
    )

    chain = AnalyseLlm | PydanticOutputParser(pydantic_object=SelectorResult)
    result = await chain.ainvoke([HumanMessage(content=prompt)])

    # llm = AnalyseLlm.with_structured_output(SelectorResult)
    # result = await llm.ainvoke([HumanMessage(content=prompt)])
    
    next_selector = result.selector
    if not next_selector:
        # 有分页控件但无可点击的下一页（仅一页），统一设为无分页
        print(f"[节点3] 无可点击的下一页: {result.reason}")
        return {
            "selector": None,
            "has_pagination": 0,
            "is_valid": True
        }
    
    # 组合完整选择器
    selector = f"{pagination_selector} {next_selector}"
    
    # 检查是否已失败过
    if selector in failed_selectors:
        print(f"[节点3] 选择器已失败过: {selector}")
        return {
            "selector": None,
            "failed_selectors": failed_selectors,
            "retry_count": retry_count + 1
        }
    
    print(f"[节点3] 选择器: {selector}")
    
    # 验证元素存在
    element = await page.query_selector(selector)
    if not element:
        print("[节点3] 选择器未匹配到元素")
        return {
            "selector": None,
            "failed_selectors": failed_selectors + [selector],
            "retry_count": retry_count + 1
        }
    
    return {"selector": selector}


async def validate_next(state: NextPageState) -> dict:
    """节点4: 验证下一页"""
    selector = state["selector"]
    page = state["page"]
    url = state["url"]
    failed_selectors = state.get("failed_selectors", [])
    retry_count = state.get("retry_count", 0)
    
    print(f"[节点4] 验证选择器: {selector}")
    
    context = page.context
    
    # 1. 记录状态
    before_url = page.url
    tabs_before = len(context.pages)
    content_before = await page.content()
    hash_before = hashlib.md5(content_before.encode()).hexdigest()
    
    # 2. 点击（先 hover 触发可能的显示效果）
    try:
        element = page.locator(selector).first
        await element.scroll_into_view_if_needed()
        await asyncio.sleep(0.2)
        await element.hover()
        await asyncio.sleep(0.3)
        await element.click()
    except Exception as e:
        print(f"[节点4] 点击失败: {e}")
        return {
            "is_valid": False,
            "change_type": "no_change",
            "failed_selectors": failed_selectors + [selector],
            "retry_count": retry_count + 1
        }
    
    await asyncio.sleep(3)
    
    # 3. 检测变化
    tabs_after = len(context.pages)
    after_url = page.url
    content_after = await page.content()
    hash_after = hashlib.md5(content_after.encode()).hexdigest()
    
    if tabs_after > tabs_before:
        change_type = "new_tab"
        # 关闭新标签
        await context.pages[-1].close()
    elif after_url != before_url:
        change_type = "url_change"
    elif hash_after != hash_before:
        change_type = "content_change"
    else:
        change_type = "no_change"
    
    print(f"[节点4] 变化类型: {change_type}")
    
    # 4. 恢复状态
    if change_type in ("url_change", "content_change"):
        await page.goto(url, wait_until="load", timeout=60000)
        await asyncio.sleep(2)
    
    # 5. 判断结果
    if change_type == "no_change":
        print("[节点4] 验证失败: 点击后无变化")
        return {
            "is_valid": False,
            "change_type": change_type,
            "failed_selectors": failed_selectors + [selector],
            "retry_count": retry_count + 1
        }
    else:
        print("[节点4] 验证成功!")
        return {
            "is_valid": True,
            "change_type": change_type
        }