import os
import requests
from bs4 import BeautifulSoup
from concurrent.futures import ThreadPoolExecutor


from PIL import Image
import io
from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas
from utils import ArrayUtil


def get_html(url, max_retries=3):
    session = requests.Session()
    adapter = requests.adapters.HTTPAdapter(max_retries=max_retries)
    session.mount("http://", adapter)
    session.mount("https://", adapter)

    try:
        response = session.get(url)
        response.raise_for_status()
        return response.text
    except Exception as e:
        print(f"Error occurred while fetching HTML from {url}: {e}")
        raise Exception("获取网页html失败")


def download_image(img_url, max_retries=5):
    for retry in range(max_retries):
        try:
            with requests.get(img_url, stream=True) as response:
                response.raise_for_status()
                return response.content
        except Exception as e:
            if retry < max_retries - 1:
                print(
                    f"Failed to download image, retrying ({retry+1}/{max_retries})..."
                )
            else:
                print("Failed to download image after multiple retries, skipping.")
                return None


def get_img_urls(html_content):
    soup = BeautifulSoup(html_content, "html.parser")
    img_tags = soup.find("div", class_="reading-content").find_all("img")

    img_urls = []
    for img_tag in img_tags:
        img_url = img_tag.attrs["data-src"]
        img_urls.append(img_url)
    return img_urls


def create_img_obj_list(img_url_list):
    img_obj_list = []
    for url in img_url_list:
        obj = dict()
        obj["url"] = url
        obj["data"] = None
        img_obj_list.append(obj)

    return img_obj_list


def set_img_obj_data(img_obj):
    url = img_obj["url"]
    data = download_image(url)
    if data is None:
        raise Exception("下载图片失败")
    img_obj["data"] = data


def save_images_to_directory(img_obj_list, directory_path):
    try:
        # 创建保存图片的目录（如果不存在）
        os.makedirs(directory_path, exist_ok=True)

        for idx, img_obj in enumerate(img_obj_list):
            url = img_obj["url"]
            data = img_obj["data"]

            # 获取图片的扩展名（假设url以图片扩展名结尾）
            extension = os.path.splitext(url)[1]

            # 图片文件名，这里用序号作为文件名
            file_name = f"image_{idx}{extension}"
            file_path = os.path.join(directory_path, file_name)

            # 将图片数据写入本地文件
            with open(file_path, "wb") as file:
                file.write(data)

        print("图片保存成功！")
    except Exception as e:
        print(f"图片保存失败：{e}")


def generate_pdf_from_images(img_obj_list, output_file):
    try:
        c = canvas.Canvas(output_file, pagesize=letter)

        for img_obj in img_obj_list:
            # 从图片对象的 data 字段中创建图像对象
            img_data = img_obj["data"]
            img = Image.open(io.BytesIO(img_data))

            # 将图像大小调整为 PDF 页面大小
            img_width, img_height = img.size
            pdf_width, pdf_height = letter
            scale = min(pdf_width / img_width, pdf_height / img_height)
            new_width, new_height = int(img_width * scale), int(img_height * scale)
            img = img.resize((new_width, new_height), Image.ANTIALIAS)

            # 将图像添加到 PDF 页面中
            c.drawInlineImage(img, 0, 0, width=new_width, height=new_height)

            # 创建新的页面
            c.showPage()

        c.save()
        print("PDF 生成成功！")
    except Exception as e:
        print(f"PDF 生成失败：{e}")


def concatenate_images_vertically(img_obj_list, output_file):
    try:
        # 计算拼接后的长图宽度和总高度
        max_width = max(
            Image.open(io.BytesIO(img_obj["data"])).width for img_obj in img_obj_list
        )
        total_height = sum(
            Image.open(io.BytesIO(img_obj["data"])).height for img_obj in img_obj_list
        )

        # 创建一张新的长图
        long_image = Image.new("RGB", (max_width, total_height), color=(255, 255, 255))

        # 依次将图片在垂直方向上拼接起来
        y_offset = 0
        for img_obj in img_obj_list:
            img = Image.open(io.BytesIO(img_obj["data"]))
            img_width, img_height = img.size
            x_offset = (max_width - img_width) // 2  # 居中拼接
            long_image.paste(img, (x_offset, y_offset))
            y_offset += img_height

        # 保存拼接后的长图到本地
        # long_image.save(output_file)
        

    except Exception as e:
        print(f"拼接图片失败：{e}")
        return None


def process_batch(lines):
    for line in lines:
        line = line.strip()  # 去掉每行开头和结尾的空白字符
        if line:
            # 解析出 HTML 文件名和 URL 地址
            file_name, _, url = line.partition(" - ")
            html_content = get_html(url)
            img_url_list = get_img_urls(html_content)
            img_obj_list = create_img_obj_list(img_url_list)

            # 使用 ThreadPoolExecutor 创建线程池
            with ThreadPoolExecutor() as executor:
                # 多线程处理图片下载和替换
                executor.map(set_img_obj_data, img_obj_list)

            # save_images_to_directory(img_obj_list, directory_path="imgs")
            concatenate_images_vertically(
                img_obj_list, output_file=f"imgs/{file_name}.pdf"
            )


if __name__ == "__main__":
    file_name = "input.txt"
    batch_size = 3  # 每个线程处理的行数

    with open(file_name, "r", encoding="utf-8") as file:
        lines = file.readlines()

    # 使用 ThreadPoolExecutor 创建线程池
    with ThreadPoolExecutor() as executor:
        # 按照 batch_size 将行分批次处理
        for i in range(0, len(lines), batch_size):
            batch_lines = lines[i : i + batch_size]
            executor.submit(process_batch, batch_lines)