from fastapi import APIRouter, HTTPException, Depends
from fastapi.responses import StreamingResponse
from openpyxl import Workbook, load_workbook
from openpyxl.styles import Font, Alignment, Border, Side
import io
import os

from ..database import get_db_cursor
from ..models import TokenPayload
from .auth import get_current_user, is_admin

router = APIRouter()

TEMPLATE_DIR = os.path.join(os.path.dirname(__file__), "..", "templates")


def create_default_workbook(meeting: dict, conclusions: list, actions: list) -> Workbook:
    """Create Excel workbook with meeting data."""
    wb = Workbook()
    ws = wb.active
    ws.title = "Meeting Record"

    # Styles
    header_font = Font(bold=True, size=14)
    label_font = Font(bold=True)
    thin_border = Border(
        left=Side(style="thin"),
        right=Side(style="thin"),
        top=Side(style="thin"),
        bottom=Side(style="thin"),
    )

    # Title
    ws.merge_cells("A1:F1")
    ws["A1"] = "Meeting Record"
    ws["A1"].font = Font(bold=True, size=16)
    ws["A1"].alignment = Alignment(horizontal="center")

    # Metadata section
    row = 3
    metadata = [
        ("Subject", meeting.get("subject", "")),
        ("Date/Time", str(meeting.get("meeting_time", ""))),
        ("Location", meeting.get("location", "")),
        ("Chairperson", meeting.get("chairperson", "")),
        ("Recorder", meeting.get("recorder", "")),
        ("Attendees", meeting.get("attendees", "")),
    ]

    for label, value in metadata:
        ws[f"A{row}"] = label
        ws[f"A{row}"].font = label_font
        ws.merge_cells(f"B{row}:F{row}")
        ws[f"B{row}"] = value
        row += 1

    # Conclusions section
    row += 1
    ws.merge_cells(f"A{row}:F{row}")
    ws[f"A{row}"] = "Conclusions"
    ws[f"A{row}"].font = header_font
    row += 1

    ws[f"A{row}"] = "Code"
    ws[f"B{row}"] = "Content"
    ws[f"A{row}"].font = label_font
    ws[f"B{row}"].font = label_font
    row += 1

    for c in conclusions:
        ws[f"A{row}"] = c.get("system_code", "")
        ws.merge_cells(f"B{row}:F{row}")
        ws[f"B{row}"] = c.get("content", "")
        row += 1

    # Action Items section
    row += 1
    ws.merge_cells(f"A{row}:F{row}")
    ws[f"A{row}"] = "Action Items"
    ws[f"A{row}"].font = header_font
    row += 1

    headers = ["Code", "Content", "Owner", "Due Date", "Status"]
    for col, header in enumerate(headers, 1):
        cell = ws.cell(row=row, column=col, value=header)
        cell.font = label_font
        cell.border = thin_border
    row += 1

    for a in actions:
        ws.cell(row=row, column=1, value=a.get("system_code", "")).border = thin_border
        ws.cell(row=row, column=2, value=a.get("content", "")).border = thin_border
        ws.cell(row=row, column=3, value=a.get("owner", "")).border = thin_border
        ws.cell(row=row, column=4, value=str(a.get("due_date", "") or "")).border = thin_border
        ws.cell(row=row, column=5, value=a.get("status", "")).border = thin_border
        row += 1

    # Adjust column widths
    ws.column_dimensions["A"].width = 18
    ws.column_dimensions["B"].width = 40
    ws.column_dimensions["C"].width = 15
    ws.column_dimensions["D"].width = 12
    ws.column_dimensions["E"].width = 12
    ws.column_dimensions["F"].width = 12

    return wb


@router.get("/meetings/{meeting_id}/export")
async def export_meeting(
    meeting_id: int, current_user: TokenPayload = Depends(get_current_user)
):
    """Export meeting to Excel file."""
    with get_db_cursor() as cursor:
        cursor.execute(
            "SELECT * FROM meeting_records WHERE meeting_id = %s", (meeting_id,)
        )
        meeting = cursor.fetchone()

        if not meeting:
            raise HTTPException(status_code=404, detail="Meeting not found")

        # Check access
        if not is_admin(current_user):
            if (
                meeting["created_by"] != current_user.email
                and meeting["recorder"] != current_user.email
                and current_user.email not in (meeting["attendees"] or "")
            ):
                raise HTTPException(status_code=403, detail="Access denied")

        # Get conclusions
        cursor.execute(
            "SELECT * FROM meeting_conclusions WHERE meeting_id = %s", (meeting_id,)
        )
        conclusions = cursor.fetchall()

        # Get action items
        cursor.execute(
            "SELECT * FROM meeting_action_items WHERE meeting_id = %s", (meeting_id,)
        )
        actions = cursor.fetchall()

    # Check for custom template
    template_path = os.path.join(TEMPLATE_DIR, "template.xlsx")
    if os.path.exists(template_path):
        wb = load_workbook(template_path)
        ws = wb.active

        # Replace placeholders
        for row in ws.iter_rows():
            for cell in row:
                if cell.value and isinstance(cell.value, str):
                    cell.value = (
                        cell.value.replace("{{subject}}", meeting.get("subject", ""))
                        .replace("{{time}}", str(meeting.get("meeting_time", "")))
                        .replace("{{location}}", meeting.get("location", ""))
                        .replace("{{chair}}", meeting.get("chairperson", ""))
                        .replace("{{recorder}}", meeting.get("recorder", ""))
                        .replace("{{attendees}}", meeting.get("attendees", ""))
                    )
    else:
        # Use default template
        wb = create_default_workbook(meeting, conclusions, actions)

    # Save to bytes buffer
    buffer = io.BytesIO()
    wb.save(buffer)
    buffer.seek(0)

    filename = f"meeting_{meeting.get('uuid', meeting_id)}.xlsx"

    return StreamingResponse(
        buffer,
        media_type="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
        headers={"Content-Disposition": f'attachment; filename="{filename}"'},
    )