"""
PDF generation using ReportLab.
This module provides functions to create PDF documents directly.
"""

import os
from io import BytesIO
from reportlab.lib.pagesizes import letter, A4
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import inch, cm
from reportlab.lib.colors import black, grey
from reportlab.platypus import SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle
from reportlab.platypus.flowables import PageBreak
from reportlab.lib.enums import TA_LEFT, TA_CENTER, TA_RIGHT
from utils import log_error


def create_pdf_resume(data, template_type="standard"):
    """
    Create a PDF resume using ReportLab.
    
    Args:
        data (dict): Resume data
        template_type (str): 'standard' or 'modern'
        
    Returns:
        bytes: PDF bytes
    """
    try:
        buffer = BytesIO()
        
        if template_type == "modern":
            doc = SimpleDocTemplate(buffer, pagesize=A4, 
                                  leftMargin=0.5*inch, rightMargin=0.5*inch,
                                  topMargin=0.5*inch, bottomMargin=0.5*inch)
            elements = _create_modern_resume_elements(data)
        else:
            doc = SimpleDocTemplate(buffer, pagesize=A4,
                                  leftMargin=0.75*inch, rightMargin=0.75*inch,
                                  topMargin=0.75*inch, bottomMargin=0.75*inch)
            elements = _create_standard_resume_elements(data)
        
        doc.build(elements)
        pdf_bytes = buffer.getvalue()
        buffer.close()
        
        return pdf_bytes
        
    except Exception as e:
        log_error(f"PDF creation failed: {str(e)}", e)
        return None


def _create_standard_resume_elements(data):
    """Create elements for standard resume template."""
    styles = getSampleStyleSheet()
    elements = []
    
    # Custom styles
    styles.add(ParagraphStyle(
        name='Name',
        parent=styles['Heading1'],
        fontSize=24,
        spaceAfter=12,
        alignment=TA_CENTER
    ))
    
    styles.add(ParagraphStyle(
        name='Contact',
        parent=styles['Normal'],
        fontSize=10,
        spaceAfter=30,
        alignment=TA_CENTER
    ))
    
    styles.add(ParagraphStyle(
        name='SectionTitle',
        parent=styles['Heading2'],
        fontSize=14,
        spaceBefore=20,
        spaceAfter=10,
        borderWidth=1,
        borderColor=grey,
        borderPadding=5
    ))
    
    styles.add(ParagraphStyle(
        name='JobTitle',
        parent=styles['Heading3'],
        fontSize=12,
        spaceAfter=2
    ))
    
    styles.add(ParagraphStyle(
        name='Company',
        parent=styles['Normal'],
        fontSize=11,
        textColor=grey,
        spaceAfter=5
    ))
    
    styles.add(ParagraphStyle(
        name='Date',
        parent=styles['Normal'],
        fontSize=10,
        textColor=grey,
        alignment=TA_RIGHT
    ))
    
    # Name
    elements.append(Paragraph(data.get('name', ''), styles['Name']))
    
    # Contact info
    contact_info = []
    if data.get('email'):
        contact_info.append(f"Email: {data['email']}")
    if data.get('phone'):
        contact_info.append(f"Phone: {data['phone']}")
    if data.get('linkedin'):
        contact_info.append(f"LinkedIn: {data['linkedin']}")
    if data.get('github'):
        contact_info.append(f"GitHub: {data['github']}")
    
    if contact_info:
        elements.append(Paragraph(" | ".join(contact_info), styles['Contact']))
    
    # Profile Summary
    if data.get('summary'):
        elements.append(Paragraph("Profile Summary", styles['SectionTitle']))
        elements.append(Paragraph(data['summary'], styles['Normal']))
    
    # Add sections based on order
    sections_order = data.get('sections_order', [])
    
    for section in sections_order:
        if section == 'work_experience' and data.get('work_experience'):
            elements.append(Paragraph("Work Experience", styles['SectionTitle']))
            for exp in data['work_experience']:
                elements.append(Paragraph(exp.get('title', ''), styles['JobTitle']))
                elements.append(Paragraph(exp.get('organization', ''), styles['Company']))
                
                # Create table for date and remarks
                date_data = [[
                    Paragraph(f"{exp.get('start_date', '')} - {exp.get('end_date', 'Present')}", styles['Date']),
                    Paragraph(exp.get('remarks', ''), styles['Normal'])
                ]]
                date_table = Table(date_data, colWidths=[2*inch, 4*inch])
                date_table.setStyle(TableStyle([
                    ('VALIGN', (0, 0), (-1, -1), 'TOP'),
                ]))
                elements.append(date_table)
                elements.append(Spacer(1, 10))
                
        elif section == 'projects' and data.get('projects'):
            elements.append(Paragraph("Projects", styles['SectionTitle']))
            for proj in data['projects']:
                elements.append(Paragraph(proj.get('title', ''), styles['JobTitle']))
                elements.append(Paragraph(proj.get('organization', ''), styles['Company']))
                
                date_data = [[
                    Paragraph(f"{proj.get('start_date', '')} - {proj.get('end_date', 'Present')}", styles['Date']),
                    Paragraph(proj.get('remarks', ''), styles['Normal'])
                ]]
                date_table = Table(date_data, colWidths=[2*inch, 4*inch])
                date_table.setStyle(TableStyle([
                    ('VALIGN', (0, 0), (-1, -1), 'TOP'),
                ]))
                elements.append(date_table)
                elements.append(Spacer(1, 10))
                
        elif section == 'education' and data.get('education'):
            elements.append(Paragraph("Education", styles['SectionTitle']))
            for edu in data['education']:
                elements.append(Paragraph(edu.get('title', ''), styles['JobTitle']))
                elements.append(Paragraph(edu.get('organization', ''), styles['Company']))
                
                date_data = [[
                    Paragraph(f"{edu.get('start_date', '')} - {edu.get('end_date', 'Present')}", styles['Date']),
                    Paragraph(edu.get('remarks', ''), styles['Normal'])
                ]]
                date_table = Table(date_data, colWidths=[2*inch, 4*inch])
                date_table.setStyle(TableStyle([
                    ('VALIGN', (0, 0), (-1, -1), 'TOP'),
                ]))
                elements.append(date_table)
                elements.append(Spacer(1, 10))
                
        elif section == 'skills' and data.get('skills'):
            elements.append(Paragraph("Skills", styles['SectionTitle']))
            skills_list = [skill.strip() for skill in data['skills'].split(',')]
            elements.append(Paragraph(", ".join(skills_list), styles['Normal']))
            
        elif section == 'achievements' and data.get('achievements'):
            elements.append(Paragraph("Achievements", styles['SectionTitle']))
            achievements_list = [achievement.strip() for achievement in data['achievements'].split(',')]
            elements.append(Paragraph(", ".join(achievements_list), styles['Normal']))
    
    return elements


def _create_modern_resume_elements(data):
    """Create elements for modern resume template (two-column)."""
    styles = getSampleStyleSheet()
    elements = []
    
    # Custom styles
    styles.add(ParagraphStyle(
        name='Name',
        parent=styles['Heading1'],
        fontSize=20,
        spaceAfter=12,
        alignment=TA_CENTER
    ))
    
    styles.add(ParagraphStyle(
        name='Contact',
        parent=styles['Normal'],
        fontSize=9,
        spaceAfter=20,
        alignment=TA_CENTER
    ))
    
    styles.add(ParagraphStyle(
        name='SectionTitle',
        parent=styles['Heading2'],
        fontSize=12,
        spaceBefore=15,
        spaceAfter=8,
        textColor=black
    ))
    
    styles.add(ParagraphStyle(
        name='JobTitle',
        parent=styles['Heading3'],
        fontSize=11,
        spaceAfter=2
    ))
    
    styles.add(ParagraphStyle(
        name='Company',
        parent=styles['Normal'],
        fontSize=10,
        textColor=grey,
        spaceAfter=5
    ))
    
    styles.add(ParagraphStyle(
        name='Date',
        parent=styles['Normal'],
        fontSize=9,
        textColor=grey,
        alignment=TA_RIGHT
    ))
    
    # Header (full width)
    elements.append(Paragraph(data.get('name', ''), styles['Name']))
    
    # Contact info
    contact_info = []
    if data.get('email'):
        contact_info.append(f"Email: {data['email']}")
    if data.get('phone'):
        contact_info.append(f"Phone: {data['phone']}")
    if data.get('linkedin'):
        contact_info.append(f"LinkedIn: {data['linkedin']}")
    if data.get('github'):
        contact_info.append(f"GitHub: {data['github']}")
    
    if contact_info:
        elements.append(Paragraph(" | ".join(contact_info), styles['Contact']))
    
    # Two-column layout
    left_col_width = 2.5 * inch
    right_col_width = 4.5 * inch
    
    # Main content (right column)
    main_elements = []
    
    # Profile Summary
    if data.get('summary'):
        main_elements.append(Paragraph("Profile Summary", styles['SectionTitle']))
        main_elements.append(Paragraph(data['summary'], styles['Normal']))
    
    # Add sections to main content
    sections_order = data.get('sections_order', [])
    
    for section in sections_order:
        if section == 'work_experience' and data.get('work_experience'):
            main_elements.append(Paragraph("Work Experience", styles['SectionTitle']))
            for exp in data['work_experience']:
                main_elements.append(Paragraph(exp.get('title', ''), styles['JobTitle']))
                main_elements.append(Paragraph(exp.get('organization', ''), styles['Company']))
                main_elements.append(Paragraph(
                    f"{exp.get('start_date', '')} - {exp.get('end_date', 'Present')}", 
                    styles['Date']
                ))
                main_elements.append(Paragraph(exp.get('remarks', ''), styles['Normal']))
                main_elements.append(Spacer(1, 10))
                
        elif section == 'projects' and data.get('projects'):
            main_elements.append(Paragraph("Projects", styles['SectionTitle']))
            for proj in data['projects']:
                main_elements.append(Paragraph(proj.get('title', ''), styles['JobTitle']))
                main_elements.append(Paragraph(proj.get('organization', ''), styles['Company']))
                main_elements.append(Paragraph(
                    f"{proj.get('start_date', '')} - {proj.get('end_date', 'Present')}", 
                    styles['Date']
                ))
                main_elements.append(Paragraph(proj.get('remarks', ''), styles['Normal']))
                main_elements.append(Spacer(1, 10))
                
        elif section == 'education' and data.get('education'):
            main_elements.append(Paragraph("Education", styles['SectionTitle']))
            for edu in data['education']:
                main_elements.append(Paragraph(edu.get('title', ''), styles['JobTitle']))
                main_elements.append(Paragraph(edu.get('organization', ''), styles['Company']))
                main_elements.append(Paragraph(
                    f"{edu.get('start_date', '')} - {edu.get('end_date', 'Present')}", 
                    styles['Date']
                ))
                main_elements.append(Paragraph(edu.get('remarks', ''), styles['Normal']))
                main_elements.append(Spacer(1, 10))
    
    # Sidebar (left column)
    sidebar_elements = []
    
    # Skills
    if data.get('skills'):
        sidebar_elements.append(Paragraph("Skills", styles['SectionTitle']))
        skills_list = [skill.strip() for skill in data['skills'].split(',')]
        for skill in skills_list:
            sidebar_elements.append(Paragraph(f"• {skill}", styles['Normal']))
        sidebar_elements.append(Spacer(1, 10))
    
    # Achievements
    if data.get('achievements'):
        sidebar_elements.append(Paragraph("Achievements", styles['SectionTitle']))
        achievements_list = [achievement.strip() for achievement in data['achievements'].split(',')]
        for achievement in achievements_list:
            sidebar_elements.append(Paragraph(f"• {achievement}", styles['Normal']))
    
    # Create two-column table
    all_elements = []
    max_len = max(len(main_elements), len(sidebar_elements))
    
    for i in range(max_len):
        left = sidebar_elements[i] if i < len(sidebar_elements) else Spacer(1, 1)
        right = main_elements[i] if i < len(main_elements) else Spacer(1, 1)
        all_elements.append([left, right])
    
    if all_elements:
        col_table = Table(all_elements, colWidths=[left_col_width, right_col_width])
        col_table.setStyle(TableStyle([
            ('VALIGN', (0, 0), (-1, -1), 'TOP'),
        ]))
        elements.append(col_table)
    
    return elements