utils/builder.py

import logging
import os
import re
from datetime import datetime
from dateutil.parser import parse as date_parse
from docx import Document
from docx.enum.text import WD_PARAGRAPH_ALIGNMENT, WD_TAB_ALIGNMENT
from docx.shared import Inches, Pt

logger = logging.getLogger(__name__)


def fmt_range(raw: str) -> str:
    """Formats a date range string nicely."""
    if not raw:
        return ""
    parts = [p.strip() for p in re.split(r"\s*[–-]\s*", raw)]
    
    formatted_parts = []
    for part in parts:
        if part.lower() == "present":
            formatted_parts.append("Present")
        else:
            try:
                date_obj = date_parse(part, fuzzy=True, default=datetime(1900, 1, 1))
                if date_obj.year == 1900:
                    formatted_parts.append(part)
                else:
                    formatted_parts.append(date_obj.strftime("%B %Y"))
            except (ValueError, TypeError):
                formatted_parts.append(part)
    
    return " – ".join(formatted_parts)


def add_section_heading(doc, text):
    """Adds a centered section heading."""
    p = doc.add_paragraph()
    run = p.add_run(text.upper())
    run.bold = True
    font = run.font
    font.size = Pt(12)
    font.name = 'Arial'
    p.alignment = WD_PARAGRAPH_ALIGNMENT.CENTER
    p.paragraph_format.space_after = Pt(6)


def build_resume_from_data(tmpl: str, sections: dict, remove_blank_pages_enabled: bool = True) -> Document:
    """
    Builds a formatted resume from structured data, inserting header/footer images and logging the process.
    """
    logger.info("BUILDER: Starting image-based resume build process.")
    try:
        # 1. Create a new blank document, ignoring the template file
        doc = Document()
        logger.info("BUILDER: Successfully created a new blank document.")
        
        # Get section and enable different first page header/footer
        section = doc.sections[0]
        section.different_first_page = True

        # Move header and footer to the very edge of the page
        section.header_distance = Pt(0)
        section.footer_distance = Pt(0)
        logger.info("BUILDER: Set header/footer distance to 0 to remove whitespace.")

        # 2. Define image paths relative to the project root
        script_dir = os.path.dirname(os.path.abspath(__file__))
        project_root = os.path.dirname(script_dir)
        header_path = os.path.join(project_root, 'header.png')
        footer_path = os.path.join(project_root, 'footer.png')
        
        logger.info(f"BUILDER: Attempting to use header image from: {header_path}")
        logger.info(f"BUILDER: Attempting to use footer image from: {footer_path}")

        if not os.path.exists(header_path):
            logger.error(f"BUILDER FATAL: Header image not found at '{header_path}'. Cannot proceed.")
            return doc # Return empty doc
        if not os.path.exists(footer_path):
            logger.error(f"BUILDER FATAL: Footer image not found at '{footer_path}'. Cannot proceed.")
            return doc # Return empty doc

        # 3. Setup Headers
        candidate_name = sections.get("Name", "Candidate Name Not Found")
        experiences = sections.get("StructuredExperiences", [])
        job_title = experiences[0].get("title", "") if experiences else ""
        
        # -- First Page Header (Image + Name + Title) --
        first_page_header = section.first_page_header
        first_page_header.is_linked_to_previous = False
        
        # Safely get or create a paragraph for the image
        p_header_img_first = first_page_header.paragraphs[0] if first_page_header.paragraphs else first_page_header.add_paragraph()
        p_header_img_first.clear()
        
        p_header_img_first.paragraph_format.space_before = Pt(0)
        p_header_img_first.paragraph_format.space_after = Pt(0)
        p_header_img_first.paragraph_format.left_indent = -section.left_margin
        p_header_img_first.add_run().add_picture(header_path, width=section.page_width)
        logger.info("BUILDER: Inserted header.png into FIRST PAGE header.")
        
        # Add Name
        p_name = first_page_header.add_paragraph()
        run_name = p_name.add_run(candidate_name.upper())
        run_name.font.name = 'Arial'
        run_name.font.size = Pt(14)
        run_name.bold = True
        p_name.alignment = WD_PARAGRAPH_ALIGNMENT.CENTER
        p_name.paragraph_format.space_before = Pt(6)
        p_name.paragraph_format.space_after = Pt(0)
        logger.info(f"BUILDER: Added candidate name '{candidate_name}' to FIRST PAGE header.")
        
        # Add Job Title
        if job_title:
            p_title = first_page_header.add_paragraph()
            run_title = p_title.add_run(job_title)
            run_title.font.name = 'Arial'
            run_title.font.size = Pt(11)
            p_title.alignment = WD_PARAGRAPH_ALIGNMENT.CENTER
            p_title.paragraph_format.space_before = Pt(0)
            logger.info(f"BUILDER: Added job title '{job_title}' to FIRST PAGE header.")

        # -- Primary Header for subsequent pages (Image Only) --
        primary_header = section.header
        primary_header.is_linked_to_previous = False
        
        # Safely get or create a paragraph for the image
        p_header_img_primary = primary_header.paragraphs[0] if primary_header.paragraphs else primary_header.add_paragraph()
        p_header_img_primary.clear()

        p_header_img_primary.paragraph_format.space_before = Pt(0)
        p_header_img_primary.paragraph_format.space_after = Pt(0)
        p_header_img_primary.paragraph_format.left_indent = -section.left_margin
        p_header_img_primary.add_run().add_picture(header_path, width=section.page_width)
        logger.info("BUILDER: Inserted header.png into PRIMARY header for subsequent pages.")

        # 4. Insert Footer Image (same for all pages)
        footer = section.footer
        footer.is_linked_to_previous = False

        # Safely get or create a paragraph for the image
        p_footer_img = footer.paragraphs[0] if footer.paragraphs else footer.add_paragraph()
        p_footer_img.clear()

        p_footer_img.paragraph_format.space_before = Pt(0)
        p_footer_img.paragraph_format.space_after = Pt(0)
        p_footer_img.paragraph_format.left_indent = -section.left_margin
        p_footer_img.add_run().add_picture(footer_path, width=section.page_width)
        
        # Link the first page footer to the primary footer so we only define it once.
        section.first_page_footer.is_linked_to_previous = True
        logger.info("BUILDER: Inserted footer.png and configured for all pages.")

        # 5. Build Resume Body
        logger.info("BUILDER: Proceeding to add structured resume content to document body.")
        
        # --- Professional Summary ---
        if sections.get("Summary"):
            add_section_heading(doc, "Professional Summary")
            doc.add_paragraph(sections["Summary"]).paragraph_format.space_after = Pt(12)

        # --- Skills ---
        if sections.get("Skills"):
            add_section_heading(doc, "Skills")
            skills_text = ", ".join(sections["Skills"])
            p = doc.add_paragraph(skills_text)
            p.alignment = WD_PARAGRAPH_ALIGNMENT.CENTER
            p.paragraph_format.space_after = Pt(12)

        # --- Professional Experience ---
        if experiences:
            add_section_heading(doc, "Professional Experience")
            for exp in experiences:
                if not isinstance(exp, dict):
                    continue
                
                p = doc.add_paragraph()
                p.add_run(exp.get("title", "N/A")).bold = True
                p.add_run(" | ").bold = True
                p.add_run(exp.get("company", "N/A")).italic = True
                p.add_run(f'\t{fmt_range(exp.get("date_range", ""))}')

                tab_stops = p.paragraph_format.tab_stops
                tab_stops.add_tab_stop(Inches(6.5), WD_TAB_ALIGNMENT.RIGHT)
                
                responsibilities = exp.get("responsibilities", [])
                if responsibilities and isinstance(responsibilities, list):
                    for resp in responsibilities:
                        if resp.strip():
                            try:
                                p_resp = doc.add_paragraph(resp, style='List Bullet')
                            except KeyError:
                                p_resp = doc.add_paragraph(f"• {resp}")
                            
                            p_resp.paragraph_format.left_indent = Inches(0.25)
                            p_resp.paragraph_format.space_before = Pt(0)
                            p_resp.paragraph_format.space_after = Pt(3)
                
                doc.add_paragraph().paragraph_format.space_after = Pt(6)

        # --- Education ---
        if sections.get("Education"):
            add_section_heading(doc, "Education")
            for edu in sections.get("Education", []):
                if edu.strip():
                    try:
                        p_edu = doc.add_paragraph(edu, style='List Bullet')
                    except KeyError:
                        p_edu = doc.add_paragraph(f"• {edu}")
                    
                    p_edu.paragraph_format.left_indent = Inches(0.25)

        logger.info("BUILDER: Resume build process completed successfully.")
        return doc
    
    except Exception:
        logger.error("BUILDER: An unexpected error occurred during resume generation.", exc_info=True)
        return Document()