#!/usr/bin/env python3
"""One-page-per-figure atlas of docs/diagrams/*.svg → docs/architecture-diagrams.pdf."""

from __future__ import annotations

import subprocess
import tempfile
from pathlib import Path

from reportlab.lib import colors
from reportlab.lib.enums import TA_CENTER
from reportlab.lib.pagesizes import letter
from reportlab.lib.styles import ParagraphStyle, getSampleStyleSheet
from reportlab.lib.units import inch
from reportlab.platypus import Image, PageBreak, Paragraph, SimpleDocTemplate, Spacer

ROOT = Path(__file__).resolve().parents[1]
DIAG = ROOT / "docs" / "diagrams"
OUT = ROOT / "docs" / "architecture-diagrams.pdf"
NAVY = colors.HexColor("#0F2744")
TEAL = colors.HexColor("#1A6B6B")

TITLES = {
    "01-high-level-architecture.svg": "High-level architecture",
    "02-security-boundaries.svg": "Security boundaries",
    "03-auth-two-hop.svg": "Two-hop authentication",
    "04-flow-async-timestamp.svg": "Create Timestamp (async + hook)",
    "05-flow-wait.svg": "Create Timestamp and Wait",
    "06-nats-topology.svg": "NATS subject topology",
    "07-operations-map.svg": "Operations map",
    "08-middleware-internals.svg": "Middleware internals",
    "09-phase-roadmap.svg": "Phase roadmap",
    "10-workspace-integration.svg": "Workspace integration",
    "11-zapier-billing.svg": "Zapier and Verae billing layers",
    "12-peergos-ipfs-tiered-storage.svg": "Peergos / IPFS / cold retrieve",
}


def header_footer(canvas, doc):
    canvas.saveState()
    w, h = letter
    canvas.setFillColor(NAVY)
    canvas.rect(0, h - 28, w, 28, fill=1, stroke=0)
    canvas.setFillColor(colors.white)
    canvas.setFont("Helvetica", 8)
    canvas.drawString(0.7 * inch, h - 18, "Verae Time  x  Zapier")
    canvas.drawRightString(w - 0.7 * inch, h - 18, "Architecture diagrams")
    canvas.setFillColor(TEAL)
    canvas.rect(0, 0, w, 22, fill=1, stroke=0)
    canvas.setFillColor(colors.white)
    canvas.setFont("Helvetica", 8)
    canvas.drawString(0.7 * inch, 8, "Internal  ·  18 August 2026  ·  SVG sources in docs/diagrams/")
    canvas.drawRightString(w - 0.7 * inch, 8, str(doc.page))
    canvas.restoreState()


def main():
    base = getSampleStyleSheet()
    title_s = ParagraphStyle(
        "t", parent=base["Title"], fontName="Helvetica-Bold", fontSize=22,
        textColor=NAVY, alignment=TA_CENTER, spaceAfter=10,
    )
    cap = ParagraphStyle(
        "c", parent=base["Normal"], fontName="Helvetica", fontSize=10,
        textColor=NAVY, alignment=TA_CENTER, spaceBefore=6, spaceAfter=4,
    )
    body = ParagraphStyle(
        "b", parent=base["Normal"], fontName="Helvetica", fontSize=10,
        textColor=colors.HexColor("#334155"), alignment=TA_CENTER, leading=14,
    )
    tmp = Path(tempfile.mkdtemp(prefix="diag-pdf-"))
    svgs = sorted(DIAG.glob("*.svg"))
    usable_w = letter[0] - 1.2 * inch
    usable_h = letter[1] - 1.6 * inch

    story = [
        Spacer(1, 2.2 * inch),
        Paragraph("Architecture diagram atlas", title_s),
        Paragraph(
            "Vector sources live in docs/diagrams/. This PDF is a print/review pack "
            "of the same figures used in getting-started.pdf.",
            body,
        ),
        PageBreak(),
    ]
    for svg in svgs:
        png = tmp / (svg.stem + ".png")
        subprocess.run(
            ["rsvg-convert", "-w", "1800", "-f", "png", "-o", str(png), str(svg)],
            check=True,
        )
        # keep aspect, fit page
        # unknown px size: use viewBox from svg
        text = svg.read_text(encoding="utf-8", errors="ignore")
        import re
        m = re.search(r'viewBox="0 0 (\d+) (\d+)"', text)
        vw, vh = (int(m.group(1)), int(m.group(2))) if m else (1100, 620)
        scale = min(usable_w / vw, usable_h / vh)
        iw, ih = vw * scale, vh * scale
        story.append(Paragraph(TITLES.get(svg.name, svg.stem), cap))
        story.append(Image(str(png), width=iw, height=ih))
        story.append(Paragraph(svg.name, body))
        story.append(PageBreak())
    if story[-1].__class__.__name__ == "PageBreak":
        story.pop()

    doc = SimpleDocTemplate(
        str(OUT),
        pagesize=letter,
        leftMargin=0.6 * inch,
        rightMargin=0.6 * inch,
        topMargin=0.5 * inch,
        bottomMargin=0.4 * inch,
        title="Verae Time x Zapier — architecture diagram atlas",
        author="Verae / Zapier research workspace",
    )
    doc.build(story, onFirstPage=header_footer, onLaterPages=header_footer)
    print(f"wrote {OUT} ({OUT.stat().st_size} bytes, {len(svgs)} figures)")


if __name__ == "__main__":
    main()