pdf_certificate.py

"""
pdf_certificate.py — SiteWarden Compliance Certificate Generator
=================================================================
Generates a professional PDF compliance report with:
  - Header with logo, title, timestamp, document ID
  - Executive summary
  - Detected violations
  - Applied corrections
  - Verification status
  - Before/After visual evidence
  - Footer with page numbers
"""

from __future__ import annotations

import io
import uuid
from datetime import datetime
from typing import List, Optional

from PIL import Image

from reportlab.lib import colors
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY
from reportlab.lib.pagesizes import A4
from reportlab.lib.styles import ParagraphStyle, getSampleStyleSheet
from reportlab.lib.units import mm, cm
from reportlab.platypus import (
    BaseDocTemplate,
    Frame,
    Image as RLImage,
    NextPageTemplate,
    PageBreak,
    PageTemplate,
    Paragraph,
    SimpleDocTemplate,
    Spacer,
    Table,
    TableStyle,
)


# ═══════════════════════════════════════════════════════════════
# Color palette
# ═══════════════════════════════════════════════════════════════

BLUE       = colors.HexColor("#0066cc")
DARK_BLUE  = colors.HexColor("#003d7a")
LIGHT_BLUE = colors.HexColor("#e8f0fe")
GREEN      = colors.HexColor("#28a745")
RED        = colors.HexColor("#dc3545")
GRAY       = colors.HexColor("#6c757d")
LIGHT_GRAY = colors.HexColor("#f8f9fa")
DARK       = colors.HexColor("#1a1a1a")


# ═══════════════════════════════════════════════════════════════
# PIL Image → ReportLab Image helper
# ═══════════════════════════════════════════════════════════════

def _pil_to_rl_image(pil_img: Image.Image, max_width: float, max_height: float) -> RLImage:
    """Convert a PIL Image to a ReportLab Image that fits within bounds."""
    buf = io.BytesIO()
    pil_img.save(buf, format="PNG")
    buf.seek(0)

    img_w, img_h = pil_img.size
    ratio = min(max_width / img_w, max_height / img_h)
    return RLImage(buf, width=img_w * ratio, height=img_h * ratio)


# ═══════════════════════════════════════════════════════════════
# Main generator
# ═══════════════════════════════════════════════════════════════

def generate_compliance_pdf(
    violations_list: List[str],
    corrections_list: List[str],
    before_image: Optional[Image.Image] = None,
    after_image: Optional[Image.Image] = None,
    regulation_name: str = "Building Accessibility Regulation",
    iteration_count: int = 1,
    context_info: str = "",
    is_generated_schematic: bool = False,
) -> bytes:
    """
    Generate a professional compliance certificate PDF.

    Returns the PDF as bytes (ready for st.download_button).
    """
    buf = io.BytesIO()
    doc = SimpleDocTemplate(
        buf,
        pagesize=A4,
        leftMargin=20 * mm,
        rightMargin=20 * mm,
        topMargin=25 * mm,
        bottomMargin=20 * mm,
    )

    page_w = A4[0] - 40 * mm  # usable width

    # ── Styles ───────────────────────────────────────────────────
    styles = getSampleStyleSheet()

    s_title = ParagraphStyle(
        "CertTitle", parent=styles["Title"],
        fontName="Helvetica-Bold", fontSize=24, leading=30,
        textColor=DARK_BLUE, alignment=TA_CENTER, spaceAfter=4 * mm,
    )
    s_subtitle = ParagraphStyle(
        "CertSubtitle", parent=styles["Normal"],
        fontName="Helvetica", fontSize=12, leading=16,
        textColor=GRAY, alignment=TA_CENTER, spaceAfter=8 * mm,
    )
    s_section = ParagraphStyle(
        "SectionHead", parent=styles["Heading2"],
        fontName="Helvetica-Bold", fontSize=14, leading=18,
        textColor=DARK_BLUE, spaceBefore=8 * mm, spaceAfter=4 * mm,
        borderWidth=0, borderPadding=0,
    )
    s_body = ParagraphStyle(
        "BodyText2", parent=styles["Normal"],
        fontName="Helvetica", fontSize=10.5, leading=15,
        textColor=DARK, alignment=TA_JUSTIFY, spaceAfter=3 * mm,
    )
    s_bullet = ParagraphStyle(
        "Bullet", parent=s_body,
        leftIndent=12 * mm, bulletIndent=4 * mm,
        spaceAfter=2 * mm,
    )
    s_meta = ParagraphStyle(
        "Meta", parent=styles["Normal"],
        fontName="Helvetica", fontSize=9, leading=12,
        textColor=GRAY, alignment=TA_CENTER,
    )
    s_img_caption = ParagraphStyle(
        "ImgCaption", parent=styles["Normal"],
        fontName="Helvetica-Bold", fontSize=10, leading=14,
        textColor=DARK_BLUE, alignment=TA_CENTER, spaceAfter=2 * mm,
    )

    # ── Build story ──────────────────────────────────────────────
    story: list = []
    now = datetime.now()
    doc_id = f"SW-{now.strftime('%Y%m%d%H%M%S')}-{uuid.uuid4().hex[:6].upper()}"

    # ── Header ───────────────────────────────────────────────────
    story.append(Paragraph("SiteWarden Compliance Certificate", s_title))
    story.append(Paragraph("Autonomous Architectural Analysis Report", s_subtitle))

    # Meta row
    meta_data = [
        [
            Paragraph(f"<b>Date:</b> {now.strftime('%d %B %Y, %H:%M')}", s_meta),
            Paragraph(f"<b>Document ID:</b> {doc_id}", s_meta),
        ]
    ]
    meta_table = Table(meta_data, colWidths=[page_w / 2] * 2)
    meta_table.setStyle(TableStyle([
        ("BACKGROUND", (0, 0), (-1, -1), LIGHT_BLUE),
        ("BOX", (0, 0), (-1, -1), 0.5, BLUE),
        ("TOPPADDING", (0, 0), (-1, -1), 6),
        ("BOTTOMPADDING", (0, 0), (-1, -1), 6),
    ]))
    story.append(meta_table)
    story.append(Spacer(1, 6 * mm))

    # ── Divider ──────────────────────────────────────────────────
    def _divider():
        d = Table([[""]], colWidths=[page_w])
        d.setStyle(TableStyle([
            ("LINEBELOW", (0, 0), (-1, -1), 1, BLUE),
            ("TOPPADDING", (0, 0), (-1, -1), 0),
            ("BOTTOMPADDING", (0, 0), (-1, -1), 0),
        ]))
        story.append(d)
        story.append(Spacer(1, 4 * mm))

    # ── Section 1: Executive Summary ─────────────────────────────
    story.append(Paragraph("1. Executive Summary", s_section))
    _divider()
    story.append(Paragraph(
        "This document certifies that the submitted floor plan has been "
        "autonomously analyzed and corrected to meet the specified building "
        "regulations by the SiteWarden AI Agent, powered by Google Gemini.",
        s_body,
    ))
    story.append(Paragraph(f"<b>Regulation Applied:</b> {regulation_name}", s_body))
    if context_info:
        story.append(Paragraph(f"<b>Building Context:</b> {context_info}", s_body))
    story.append(Spacer(1, 2 * mm))

    # ── Section 2: Detected Violations ───────────────────────────
    story.append(Paragraph("2. Detected Violations", s_section))
    _divider()
    if violations_list:
        for i, v in enumerate(violations_list, 1):
            story.append(Paragraph(
                f'<font color="{RED.hexval()}">✗</font>  <b>Violation #{i}:</b> {v}',
                s_bullet,
            ))
    else:
        story.append(Paragraph(
            '<font color="green">No violations detected — plan was already compliant.</font>',
            s_body,
        ))
    story.append(Spacer(1, 2 * mm))

    # ── Section 3: Applied Corrections / Recommendations ────────
    story.append(Paragraph("3. Recommendations &amp; Corrections", s_section))
    _divider()
    if corrections_list:
        for i, c in enumerate(corrections_list, 1):
            story.append(Paragraph(
                f'<font color="{GREEN.hexval()}">✓</font>  <b>#{i}:</b> {c}',
                s_bullet,
            ))
    else:
        story.append(Paragraph("No corrections were necessary.", s_body))
    story.append(Spacer(1, 2 * mm))

    # ── Section 4: Verification ──────────────────────────────────
    story.append(Paragraph("4. Verification", s_section))
    _divider()
    if not violations_list:
        story.append(Paragraph(
            "The submitted blueprint has been analyzed and confirmed "
            "<b>fully compliant</b> with all specified regulations.",
            s_body,
        ))
    else:
        story.append(Paragraph(
            "The submitted blueprint has been analyzed. "
            f"<b>{len(violations_list)} violation(s)</b> were identified. "
            "The recommendations above should be applied by the architect "
            "to achieve full compliance.",
            s_body,
        ))
    story.append(Paragraph(
        f"<b>Iterations required:</b> Fixed in {iteration_count} iteration{'s' if iteration_count != 1 else ''}.",
        s_body,
    ))
    story.append(Spacer(1, 4 * mm))

    # ── Section 5: Visual Evidence ───────────────────────────────
    if before_image or after_image:
        story.append(Paragraph("5. Visual Evidence", s_section))
        _divider()

        img_cells = []
        captions = []
        img_max_w = (page_w - 10 * mm) / 2
        img_max_h = 80 * mm

        if before_image:
            img_cells.append(_pil_to_rl_image(before_image, img_max_w, img_max_h))
            captions.append(Paragraph(
                "BEFORE — Original Blueprint" if not is_generated_schematic
                else "BEFORE — Initial Schematic",
                s_img_caption))
        else:
            img_cells.append(Paragraph("N/A", s_meta))
            captions.append(Paragraph("", s_meta))

        after_label = (
            "AFTER — Compliant Schematic (Demo)"
            if is_generated_schematic
            else "AFTER — Compliance Analysis"
        )
        if after_image:
            img_cells.append(_pil_to_rl_image(after_image, img_max_w, img_max_h))
            captions.append(Paragraph(after_label, s_img_caption))
        else:
            img_cells.append(Paragraph("N/A", s_meta))
            captions.append(Paragraph("", s_meta))

        img_table = Table(
            [captions, img_cells],
            colWidths=[page_w / 2] * 2,
        )
        img_table.setStyle(TableStyle([
            ("ALIGN", (0, 0), (-1, -1), "CENTER"),
            ("VALIGN", (0, 0), (-1, -1), "MIDDLE"),
            ("BOX", (0, 0), (0, -1), 0.5, BLUE),
            ("BOX", (1, 0), (1, -1), 0.5, GREEN),
            ("BACKGROUND", (0, 0), (0, 0), colors.HexColor("#fff0f0")),
            ("BACKGROUND", (1, 0), (1, 0), colors.HexColor("#f0fff0")),
            ("TOPPADDING", (0, 0), (-1, -1), 4),
            ("BOTTOMPADDING", (0, 0), (-1, -1), 4),
        ]))
        story.append(img_table)

    # ── Build PDF ────────────────────────────────────────────────
    def _footer(canvas, doc):
        canvas.saveState()
        canvas.setFont("Helvetica", 8)
        canvas.setFillColor(GRAY)
        canvas.drawString(20 * mm, 12 * mm,
                          "Generated by SiteWarden AI Agent  |  Powered by Google Gemini 3 Pro")
        canvas.drawRightString(A4[0] - 20 * mm, 12 * mm,
                               f"Page {doc.page}")
        canvas.restoreState()

    doc.build(story, onFirstPage=_footer, onLaterPages=_footer)
    return buf.getvalue()