# main.py
from fastapi import FastAPI, HTTPException, Query
from pydantic import BaseModel
from typing import List, Optional
import base64
import json
from playwright.async_api import async_playwright, TimeoutError as PlaywrightTimeoutError
import asyncio

app = FastAPI(title="Web Analyzer API")


class ScreenshotResponse(BaseModel):
    screenshot: str

class MetadataResponse(BaseModel):
    title: Optional[str]
    description: Optional[str]
    og: dict
    twitter: dict
    canonical: Optional[str]


async def get_page(url):
    pw = await async_playwright().start()
    browser = await pw.chromium.launch(headless=True)
    page = await browser.new_page()
    try:
        await page.goto(url, timeout=30000)
    except PlaywrightTimeoutError:
        raise HTTPException(status_code=504, detail="Page load timed out")
    return page, browser, pw


@app.get("/metadata", response_model=MetadataResponse)
async def get_metadata(url: str):
    page, browser, pw = await get_page(url)
    try:
        title = await page.title()
        desc = await page.get_attribute("meta[name='description']", "content")
        og = {}
        twitter = {}
        for prop in ["title", "description", "image"]:
            og[f"og:{prop}"] = await page.get_attribute(f"meta[property='og:{prop}']", "content")
            twitter[f"twitter:{prop}"] = await page.get_attribute(f"meta[name='twitter:{prop}']", "content")
        canonical = await page.get_attribute("link[rel='canonical']", "href")
        return {
            "title": title,
            "description": desc,
            "og": og,
            "twitter": twitter,
            "canonical": canonical
        }
    finally:
        await browser.close()
        await pw.stop()


@app.get("/screenshot", response_model=ScreenshotResponse)
async def get_screenshot(url: str):
    page, browser, pw = await get_page(url)
    try:
        image_bytes = await page.screenshot(full_page=True)
        image_base64 = base64.b64encode(image_bytes).decode()
        return {"screenshot": image_base64}
    finally:
        await browser.close()
        await pw.stop()


@app.get("/seo")
async def seo_audit(url: str):
    page, browser, pw = await get_page(url)
    try:
        h1_count = await page.locator("h1").count()
        imgs = await page.query_selector_all("img")
        missing_alts = [await img.get_attribute("src") for img in imgs if not await img.get_attribute("alt")]
        anchors = await page.query_selector_all("a[href]")
        internal, external = 0, 0
        for a in anchors:
            href = await a.get_attribute("href")
            if href and href.startswith("http"):
                if url in href:
                    internal += 1
                else:
                    external += 1
        robots = await page.get_attribute("meta[name='robots']", "content")
        canonical = await page.get_attribute("link[rel='canonical']", "href")
        return {
            "h1_count": h1_count,
            "missing_image_alts": missing_alts,
            "internal_links": internal,
            "external_links": external,
            "robots_meta": robots,
            "has_canonical": bool(canonical)
        }
    finally:
        await browser.close()
        await pw.stop()


@app.get("/performance")
async def performance_metrics(url: str):
    page, browser, pw = await get_page(url)
    try:
        nav_timing = await page.evaluate("JSON.stringify(performance.getEntriesByType('navigation'))")
        timing = json.loads(nav_timing)[0]
        fcp = await page.evaluate("performance.getEntriesByName('first-contentful-paint')[0]?.startTime")
        lcp = await page.evaluate("performance.getEntriesByType('largest-contentful-paint')[0]?.renderTime")
        cls_entries = await page.evaluate("JSON.stringify(performance.getEntriesByType('layout-shift'))")
        cls = sum(e['value'] for e in json.loads(cls_entries))
        return {
            "page_load_time_ms": timing['duration'],
            "first_contentful_paint": fcp,
            "largest_contentful_paint": lcp,
            "cumulative_layout_shift": cls
        }
    finally:
        await browser.close()
        await pw.stop()


@app.get("/structured-data")
async def structured_data(url: str):
    page, browser, pw = await get_page(url)
    try:
        scripts = await page.query_selector_all("script[type='application/ld+json']")
        json_ld_list = []
        for s in scripts:
            text = await s.inner_text()
            try:
                data = json.loads(text)
                json_ld_list.append(data)
            except Exception:
                continue
        types = []
        for obj in json_ld_list:
            if isinstance(obj, dict) and "@type" in obj:
                types.append(obj["@type"])
        return {
            "schema_found": bool(json_ld_list),
            "types": types,
            "schema": json_ld_list
        }
    finally:
        await browser.close()
        await pw.stop()


@app.get("/accessibility")
async def accessibility_check(url: str):
    page, browser, pw = await get_page(url)
    try:
        imgs = await page.query_selector_all("img")
        missing_alt = len([img for img in imgs if not await img.get_attribute("alt")])
        buttons = await page.query_selector_all("button")
        missing_labels = len([b for b in buttons if not await b.get_attribute("aria-label") and not await b.inner_text()])
        landmarks = []
        for tag in ["main", "nav", "footer", "header"]:
            if await page.query_selector(tag):
                landmarks.append(tag)
        return {
            "images_missing_alt": missing_alt,
            "buttons_missing_label": missing_labels,
            "landmarks": landmarks
        }
    finally:
        await browser.close()
        await pw.stop()