# PDF生成服务 - 支持中文

import os
import re
from reportlab.lib.pagesizes import A4
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import mm
from reportlab.lib import colors
from reportlab.platypus import (
    SimpleDocTemplate,
    Paragraph,
    Spacer,
    Table,
    TableStyle,
    PageBreak,
)
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_RIGHT


def register_chinese_font():
    """注册中文字体"""
    # 尝试注册系统自带的中文字体
    font_paths = [
        # Windows常用字体路径
        r"C:\Windows\Fonts\simsun.ttc",  # 宋体
        r"C:\Windows\Fonts\msyh.ttc",  # 微软雅黑
        r"C:\Windows\Fonts\STSONG.TTF",  # 华文宋体
        r"C:\Windows\Fonts\simhei.ttf",  # 黑体
        # Linux容器字体路径
        "/usr/share/fonts/truetype/wqy/wqy-microhei.ttc",
        "/usr/share/fonts/wqy-microhei/wqy-microhei.ttc",
        "/usr/share/fonts/noto/NotoSansCJK-Regular.ttc",
        "/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf",
    ]

    # 尝试注册一个可用的字体
    for font_path in font_paths:
        if os.path.exists(font_path):
            try:
                pdfmetrics.registerFont(TTFont("Chinese", font_path))
                return True
            except Exception as e:
                continue

    return False


# 尝试注册中文字体
_has_chinese_font = register_chinese_font()


def clean_text(text):
    """清理文本，移除不支持的字符"""
    if not text:
        return ""
    # 移除多余空白
    text = re.sub(r"\s+", " ", text)
    return text.strip()


class PianoPDF:
    def __init__(self):
        self.elements = []
        self.styles = getSampleStyleSheet()

        # 创建中文字体样式
        if _has_chinese_font:
            self.base_font = "Chinese"
        else:
            self.base_font = "Helvetica"

        # 标题样式
        self.title_style = ParagraphStyle(
            "CustomTitle",
            parent=self.styles["Heading1"],
            fontName=self.base_font,
            fontSize=18,
            spaceAfter=10 * mm,
            alignment=TA_CENTER,
        )

        # 副标题样式
        self.heading_style = ParagraphStyle(
            "CustomHeading",
            parent=self.styles["Heading2"],
            fontName=self.base_font,
            fontSize=14,
            spaceAfter=6 * mm,
            spaceBefore=6 * mm,
            textColor=colors.HexColor("#2c3e50"),
        )

        # 正文样式
        self.body_style = ParagraphStyle(
            "CustomBody",
            parent=self.styles["Normal"],
            fontName=self.base_font,
            fontSize=10,
            spaceAfter=4 * mm,
            leading=14,
        )

        # 表格样式
        self.table_style = TableStyle(
            [
                ("BACKGROUND", (0, 0), (-1, 0), colors.HexColor("#3498db")),
                ("TEXTCOLOR", (0, 0), (-1, 0), colors.whitesmoke),
                ("ALIGN", (0, 0), (-1, -1), "LEFT"),
                ("FONTNAME", (0, 0), (-1, 0), self.base_font),
                ("FONTSIZE", (0, 0), (-1, 0), 10),
                ("BOTTOMPADDING", (0, 0), (-1, 0), 8),
                ("BACKGROUND", (0, 1), (-1, -1), colors.white),
                ("FONTNAME", (0, 1), (-1, -1), self.base_font),
                ("FONTSIZE", (0, 1), (-1, -1), 9),
                ("GRID", (0, 0), (-1, -1), 0.5, colors.grey),
                (
                    "ROWBACKGROUNDS",
                    (0, 1),
                    (-1, -1),
                    [colors.white, colors.HexColor("#f8f9fa")],
                ),
            ]
        )

    def add_title(self, text):
        """添加标题"""
        self.elements.append(Paragraph(clean_text(text), self.title_style))
        self.elements.append(Spacer(1, 5 * mm))

    def add_heading(self, text):
        """添加副标题"""
        self.elements.append(Paragraph(clean_text(text), self.heading_style))

    def add_paragraph(self, text):
        """添加段落"""
        if text:
            self.elements.append(Paragraph(clean_text(text), self.body_style))
            self.elements.append(Spacer(1, 3 * mm))

    def add_list(self, items):
        """添加列表"""
        for item in items:
            if item:
                self.elements.append(
                    Paragraph(f"• {clean_text(item)}", self.body_style)
                )
        self.elements.append(Spacer(1, 3 * mm))

    def add_table(self, data):
        """添加表格"""
        if not data or len(data) < 2:
            return

        # 确保所有数据都是字符串
        table_data = []
        for row in data:
            table_data.append([clean_text(str(cell)) for cell in row])

        if table_data:
            table = Table(table_data)
            table.setStyle(self.table_style)
            self.elements.append(table)
            self.elements.append(Spacer(1, 5 * mm))

    def add_spacer(self, height=5 * mm):
        """添加间距"""
        self.elements.append(Spacer(1, height))


def generate_pdf(plan_id, student_name, content, output_dir, rendered_report=None):
    """
    使用reportlab生成PDF文件

    Args:
        plan_id: 方案ID
        student_name: 学员姓名
        content: 方案内容字典
        output_dir: 输出目录
        rendered_report: 可选的预渲染报告（Markdown格式），如果提供则使用模板渲染整个报告

    Returns:
        str: PDF文件路径
    """
    os.makedirs(output_dir, exist_ok=True)

    output_path = os.path.join(output_dir, f"plan_{plan_id}.pdf")

    # 创建PDF文档
    doc = SimpleDocTemplate(
        output_path,
        pagesize=A4,
        rightMargin=20 * mm,
        leftMargin=20 * mm,
        topMargin=20 * mm,
        bottomMargin=20 * mm,
    )

    pdf = PianoPDF()

    # 如果提供了预渲染的报告，使用模板渲染整个报告
    if rendered_report:
        # 解析Markdown并添加到PDF
        lines = rendered_report.split('\n')
        in_table = False
        table_data = []

        for line in lines:
            line = line.strip()
            if not line or line.startswith('---'):
                if in_table and table_data:
                    pdf.add_table(table_data)
                    table_data = []
                    in_table = False
                continue

            if line.startswith('# ') and not line.startswith('## '):
                # 一级标题作为主标题
                title = line.replace('# ', '').replace('*', '')
                pdf.add_title(title)
            elif line.startswith('## '):
                # 二级标题
                if in_table and table_data:
                    pdf.add_table(table_data)
                    table_data = []
                    in_table = False
                heading = line.replace('## ', '').replace('**', '')
                pdf.add_heading(heading)
            elif line.startswith('|') and '|' in line[1:]:
                # 表格行
                in_table = True
                cells = [c.strip() for c in line.split('|')[1:-1]]
                if cells and any(cells):
                    # 跳过表头分隔行
                    if not all(c.strip().startswith('-') for c in cells if c.strip()):
                        table_data.append(cells)
            elif line.startswith('- '):
                # 列表项
                pdf.add_paragraph(line)
            elif line and not in_table:
                # 普通段落
                pdf.add_paragraph(line.replace('**', '').replace('*', ''))
        # 表格收尾
        if in_table and table_data:
            pdf.add_table(table_data)
    else:
        # 使用原有结构化方式生成PDF
        # 标题
        pdf.add_title(f"钢琴练习方案 - {student_name}")

        # 学员信息
        pdf.add_heading("📋 学员信息")
        pdf.add_paragraph(f"学员姓名：{student_name}")
        pdf.add_paragraph(f"每日练习时间：{content.get('practice_time', 'N/A')}")
        pdf.add_paragraph(f"生成时间：{content.get('generated_at', '')}")

        # 问题诊断
        pdf.add_heading("🔍 问题诊断")
        for problem in content.get("problems", []):
            name = problem.get("name", "")
            severity = problem.get("severity", "")
            focus = problem.get("focus", {})
            pdf.add_paragraph(
                f"• {name} ({severity}) - 基础练习: {focus.get('basic', 0)}分钟, 技术练习: {focus.get('tech', 0)}分钟"
            )

        # AI报告（如果有）
        if content.get("ai_report"):
            pdf.add_heading("📝 AI个性化练习报告")
            # 将AI报告分段添加
            for line in content["ai_report"].split("\n"):
                line = line.strip()
                if line.startswith("## "):
                    pdf.add_heading(line.replace("## ", ""))
                elif line.startswith("# "):
                    pdf.add_title(line.replace("# ", ""))
                elif line.startswith("- "):
                    pdf.add_paragraph(line)
                elif line:
                    pdf.add_paragraph(line)

        # 每日练习计划
        pdf.add_heading("📅 每日练习计划")
        total_minutes = content.get("total_daily_minutes", 0)
        pdf.add_paragraph(f"总时长：{total_minutes} 分钟")

        # 表格
        table_data = [["阶段", "时长", "内容", "目的"]]
        for item in content.get("daily_schedule", []):
            table_data.append(
                [
                    item.get("phase", ""),
                    item.get("duration", ""),
                    item.get("content", ""),
                    item.get("purpose", ""),
                ]
            )
        pdf.add_table(table_data)

        # 练习建议
        pdf.add_heading("💡 练习建议")
        tips = [
            "每天在固定时间练习，养成良好习惯",
            "练习前先热身，放松手指",
            "先难后易，先练习重点部分",
            "录音回听，发现问题",
            "保持耐心，进步需要时间",
        ]
        pdf.add_list(tips)

    # 生成PDF
    doc.build(pdf.elements)

    return output_path