import io
import os
import pandas as pd
from flask import Blueprint, send_file, jsonify, make_response
from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas
from reportlab.lib import colors
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont

from ..db import get_db_connection, release_db_connection
from ..middleware import token_required

reports_blueprint = Blueprint('reports', __name__)

# Попытка зарегистрировать кириллический шрифт
FONT_PATH = os.path.join(os.path.dirname(__file__), '..', 'fonts', 'DejaVuSans.ttf')
FONT_NAME = 'DejaVuSans'

try:
    if os.path.exists(FONT_PATH):
        pdfmetrics.registerFont(TTFont(FONT_NAME, FONT_PATH))
    else:
        # Пытаемся найти системный шрифт на Windows или Linux
        sys_fonts = [
            '/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf',
            'C:\\Windows\\Fonts\\arial.ttf'
        ]
        for f in sys_fonts:
            if os.path.exists(f):
                pdfmetrics.registerFont(TTFont(FONT_NAME, f))
                break
except Exception as e:
    print(f"Warning: Could not register Cyrillic font: {e}")
    FONT_NAME = 'Helvetica' # Fallback

@reports_blueprint.route('/reports/cases/csv', methods=['GET'])
@token_required
def export_cases_csv(current_user_id):
    """
    Экспорт всех кейсов в CSV
    ---
    tags:
      - Reports
    security:
      - APIKeyHeader: []
    responses:
      200:
        description: CSV файл
    """
    conn = get_db_connection()
    query = """
        SELECT id, platform, violator_url, violator_article, my_article, comment, status, created_at 
        FROM cases 
        WHERE user_id = %s
    """
    df = pd.read_sql(query, conn, params=(current_user_id,))
    release_db_connection(conn)
    
    output = io.BytesIO()
    df.to_csv(output, index=False, encoding='utf-8-sig')
    output.seek(0)
    
    return send_file(
        output,
        mimetype='text/csv',
        as_attachment=True,
        download_name=f'cases_export_{current_user_id}.csv'
    )

@reports_blueprint.route('/reports/case/<int:case_id>/pdf', methods=['GET'])
@token_required
def export_case_pdf(current_user_id, case_id):
    """
    Генерация PDF претензии для конкретного кейса
    ---
    tags:
      - Reports
    security:
      - APIKeyHeader: []
    parameters:
      - name: case_id
        in: path
        type: integer
        required: true
    responses:
      200:
        description: PDF файл претензии
    """
    conn = get_db_connection()
    cur = conn.cursor()
    cur.execute("""
        SELECT platform, violator_url, violator_article, my_article, comment, status, created_at 
        FROM cases 
        WHERE id = %s AND user_id = %s
    """, (case_id, current_user_id))
    row = cur.fetchone()
    release_db_connection(conn)
    
    if not row:
        return jsonify({"error": "Case not found"}), 404
        
    platform, v_url, v_art, my_art, comment, status, created_at = row
    
    buffer = io.BytesIO()
    doc = SimpleDocTemplate(buffer, pagesize=letter)
    styles = getSampleStyleSheet()
    
    # Custom style for Russian text
    ru_style = ParagraphStyle(
        'Russian',
        parent=styles['Normal'],
        fontName=FONT_NAME,
        fontSize=10,
        leading=12
    )
    title_style = ParagraphStyle(
        'RussianTitle',
        parent=styles['Title'],
        fontName=FONT_NAME,
        fontSize=18,
        spaceAfter=20
    )
    
    elements = []
    
    # Header / Title
    elements.append(Paragraph(f"Официальная претензия #{case_id}", title_style))
    elements.append(Paragraph(f"Система мониторинга AutoMarket (OzonGuard)", ru_style))
    elements.append(Spacer(1, 20))
    
    # Info table
    data = [
        [Paragraph("Параметр", ru_style), Paragraph("Значение", ru_style)],
        [Paragraph("Маркетплейс", ru_style), platform.upper()],
        [Paragraph("Дата создания", ru_style), created_at.strftime('%Y-%m-%d %H:%M') if created_at else "-"],
        [Paragraph("Артикул нарушителя", ru_style), v_art],
        [Paragraph("Ссылка на товар", ru_style), Paragraph(v_url, ru_style)],
        [Paragraph("Ваш артикул", ru_style), my_art or "-"],
        [Paragraph("Текущий статус", ru_style), status.upper()]
    ]
    
    t = Table(data, colWidths=[150, 350])
    t.setStyle(TableStyle([
        ('BACKGROUND', (0, 0), (-1, 0), colors.HexColor('#2c3e50')),
        ('TEXTCOLOR', (0, 0), (-1, 0), colors.whitesmoke),
        ('ALIGN', (0, 0), (-1, -1), 'LEFT'),
        ('FONTNAME', (0, 0), (-1, -1), FONT_NAME),
        ('FONTSIZE', (0, 0), (-1, -1), 10),
        ('BOTTOMPADDING', (0, 0), (-1, 0), 12),
        ('BACKGROUND', (0, 1), (-1, -1), colors.whitesmoke),
        ('GRID', (0, 0), (-1, -1), 1, colors.grey),
        ('VALIGN', (0, 0), (-1, -1), 'MIDDLE'),
    ]))
    elements.append(t)
    elements.append(Spacer(1, 24))
    
    # Description
    elements.append(Paragraph("Описание нарушения:", ParagraphStyle('Sub', parent=ru_style, fontSize=12, spaceAfter=10)))
    elements.append(Paragraph(comment or "Комментарий отсутствует", ru_style))
    
    elements.append(Spacer(1, 40))
    elements.append(Paragraph("Сгенерировано автоматически. Данный документ является официальным уведомлением о нарушении правил платформы.", ParagraphStyle('Footer', parent=ru_style, fontSize=8, textColor=colors.grey)))
    
    doc.build(elements)
    buffer.seek(0)
    
    return send_file(
        buffer,
        mimetype='application/pdf',
        as_attachment=True,
        download_name=f'complaint_{case_id}.pdf'
    )