import asyncio
from pathlib import Path
from typing import Any, Dict, List

from docx import Document
from openpyxl import load_workbook
from reportlab.lib.pagesizes import A4
from reportlab.pdfgen import canvas


async def generate_quote_excel(
    project_data: Dict[str, Any],
    template_path: str,
    output_path: str,
) -> str:
    """
    Generate an Excel quote based on a template and structured project data.

    project_data is expected to have the following structure (from AI JSON):
    {
      "modules": [
        {
          "name": "...",
          "description": "...",
          "technical_approach": "...",
          "estimated_hours": 16,
          "unit_price": 800,
          "subtotal": 12800
        },
        ...
      ],
      "total_estimated_hours": 40,
      "total_amount": 32000,
      "notes": "..."
    }
    """

    async def _work() -> str:
        template = Path(template_path)
        output = Path(output_path)
        output.parent.mkdir(parents=True, exist_ok=True)

        wb = load_workbook(template)
        # Assume the first worksheet is used for the quote.
        ws = wb.active

        modules: List[Dict[str, Any]] = project_data.get("modules", [])
        total_amount = project_data.get("total_amount")
        total_hours = project_data.get("total_estimated_hours")
        notes = project_data.get("notes")

        # Example layout assumptions (adjust cell coordinates to match your template):
        # - Starting row for line items: 10
        # - Columns:
        #   A: index, B: module name, C: description,
        #   D: estimated hours, E: unit price, F: subtotal
        start_row = 10
        for idx, module in enumerate(modules, start=1):
            row = start_row + idx - 1
            ws[f"A{row}"] = idx
            ws[f"B{row}"] = module.get("name")
            ws[f"C{row}"] = module.get("description")
            ws[f"D{row}"] = module.get("estimated_hours")
            ws[f"E{row}"] = module.get("unit_price")
            ws[f"F{row}"] = module.get("subtotal")

        # Place total hours and amount in typical footer cells (adjust as needed).
        if total_hours is not None:
            ws["D5"] = total_hours  # e.g., total hours
        if total_amount is not None:
            ws["F5"] = total_amount  # e.g., total amount
        if notes:
            ws["B6"] = notes

        wb.save(output)
        return str(output)

    return await asyncio.to_thread(_work)


def _replace_in_paragraphs(paragraphs, mapping: Dict[str, str]) -> None:
    for paragraph in paragraphs:
        for placeholder, value in mapping.items():
            if placeholder in paragraph.text:
                # Rebuild runs to preserve basic formatting as much as possible.
                inline = paragraph.runs
                text = paragraph.text.replace(placeholder, value)
                # Clear existing runs
                for i in range(len(inline) - 1, -1, -1):
                    paragraph.runs[i].clear()
                    paragraph.runs[i].text = ""
                # Add a single run with replaced text
                paragraph.add_run(text)


def _replace_in_tables(tables, mapping: Dict[str, str]) -> None:
    for table in tables:
        for row in table.rows:
            for cell in row.cells:
                _replace_in_paragraphs(cell.paragraphs, mapping)


async def generate_contract_word(
    contract_data: Dict[str, str],
    template_path: str,
    output_path: str,
) -> str:
    """
    Generate a contract Word document by replacing placeholders.

    contract_data is a flat dict like:
      {
        "{{CUSTOMER_NAME}}": "张三",
        "{{TOTAL_PRICE}}": "￥32,000",
        "{{DELIVERY_DATE}}": "2026-03-31",
        ...
      }
    """

    async def _work() -> str:
        template = Path(template_path)
        output = Path(output_path)
        output.parent.mkdir(parents=True, exist_ok=True)

        doc = Document(str(template))

        _replace_in_paragraphs(doc.paragraphs, contract_data)
        _replace_in_tables(doc.tables, contract_data)

        doc.save(str(output))
        return str(output)

    return await asyncio.to_thread(_work)


async def generate_quote_pdf_from_data(
    project_data: Dict[str, Any],
    output_pdf_path: str,
) -> str:
    """
    Generate a simple PDF quote summary directly from structured data.
    This does not render the Excel visually, but provides a clean PDF
    that can be sent to customers.
    """

    async def _work() -> str:
        output = Path(output_pdf_path)
        output.parent.mkdir(parents=True, exist_ok=True)

        c = canvas.Canvas(str(output), pagesize=A4)
        width, height = A4

        y = height - 40
        c.setFont("Helvetica-Bold", 14)
        c.drawString(40, y, "报价单 Quote")
        y -= 30

        c.setFont("Helvetica", 10)

        modules: List[Dict[str, Any]] = project_data.get("modules", [])
        for idx, module in enumerate(modules, start=1):
            name = module.get("name", "")
            hours = module.get("estimated_hours", "")
            subtotal = module.get("subtotal", "")
            line = f"{idx}. {name} - 工时: {hours}, 小计: {subtotal}"
            c.drawString(40, y, line)
            y -= 16
            if y < 80:
                c.showPage()
                y = height - 40
                c.setFont("Helvetica", 10)

        total_amount = project_data.get("total_amount")
        total_hours = project_data.get("total_estimated_hours")

        y -= 10
        c.setFont("Helvetica-Bold", 11)
        if total_hours is not None:
            c.drawString(40, y, f"总工时 Total Hours: {total_hours}")
            y -= 18
        if total_amount is not None:
            c.drawString(40, y, f"总金额 Total Amount: {total_amount}")

        c.showPage()
        c.save()
        return str(output)

    return await asyncio.to_thread(_work)