#!/usr/bin/env bash
# setup.sh — Bootstrap a self-hosted Docsify site (static files; serve with
# any web server — Apache, nginx, Caddy, …).
#
# Run this script from your web server's document root:
#   cd /path/to/docroot
#   bash setup.sh
#
# Downloads Docsify core, the search plugin, the Vue theme, the copy-to-clipboard
# plugin, extra Prism languages (bash, yaml, python, r), KaTeX math, Mermaid diagrams,
# and UX plugins (alerts, tabs, pagination, image zoom, collapsible sidebar) —
# all served locally, no external CDN dependencies at runtime. Versions are pinned and
# a SHA-256 manifest (assets/SHA256SUMS) is written for reproducible, verifiable rebuilds.
#
# Re-running in an existing site is safe: it refreshes the assets and regenerates
# index.html, but never overwrites Markdown files (README.md, _sidebar.md, and any
# pages you have added) that already exist.

set -euo pipefail

# ── Configuration ───────────────────────────────────────────────────────────────
# All versions are pinned exactly for reproducible, CDN-independent rebuilds. Bump a
# version here, re-run, and commit the refreshed assets/ + assets/SHA256SUMS.
DOCSIFY_VERSION="4.13.1"
PRISM_VERSION="1.30.0"
COPY_CODE_VERSION="3.0.2"
FLEXIBLE_ALERTS_VERSION="1.3.0"
TABS_VERSION="1.6.3"
PAGINATION_VERSION="2.10.1"
MEDIUM_ZOOM_VERSION="1.1.0"
SIDEBAR_COLLAPSE_VERSION="1.3.5"
MERMAID_VERSION="11.15.0"
DOCSIFY_MERMAID_VERSION="2.0.1"
# Math plugin and its KaTeX renderer are coupled: the standalone KaTeX stylesheet/font
# version (KATEX_VERSION) MUST match the renderer bundled inside this docsify-katex
# release. docsify-katex 1.4.4 bundles KaTeX 0.11.1 (the 2.x line is broken). Bump the
# two together.
DOCSIFY_KATEX_VERSION="1.4.4"
KATEX_VERSION="0.11.1"

# ── Argument check ──────────────────────────────────────────────────────────────
if [[ $# -gt 0 ]]; then
  echo "This script takes no options (got: $*)." >&2
  echo "Usage: bash setup.sh" >&2
  exit 1
fi

# ── Output helpers ──────────────────────────────────────────────────────────────
GREEN='\033[0;32m'
BLUE='\033[0;34m'
YELLOW='\033[0;33m'
RED='\033[0;31m'
BOLD='\033[1m'
NC='\033[0m'

step() { echo -e "\n${BLUE}${BOLD}==> $1${NC}"; }
ok()   { echo -e "  ${GREEN}✓${NC}  $1"; }
skip() { echo -e "  ${YELLOW}•${NC}  $1"; }
die()  { echo -e "  ${RED}✗${NC}  $1" >&2; exit 1; }

# ── Preflight checks ────────────────────────────────────────────────────────────
step "Preflight checks"

command -v curl &>/dev/null \
  || die "curl is required but not found. Install curl and try again."
ok "curl $(curl --version | head -1 | awk '{print $2}')"

if [[ -f index.html ]]; then
  echo -e "  ${RED}!${NC}  index.html already exists in: $(pwd)"
  echo -e "       This re-downloads assets and regenerates index.html (edits to"
  echo -e "       index.html will be lost). Existing Markdown files are left untouched."
  read -r -p "       Continue? [y/N] " reply || reply=""   # EOF (non-interactive) -> treat as "no"
  [[ "${reply,,}" == "y" ]] || { echo "Aborted."; exit 0; }
fi

echo -e "  Working in: $(pwd)"

# ── Step 1: Directories ─────────────────────────────────────────────────────────
step "Step 1 — Creating directory structure"

mkdir -p assets/js assets/css assets/css/fonts
ok "assets/js/"
ok "assets/css/"

# ── Step 2: Download Docsify assets ─────────────────────────────────────────────
step "Step 2 — Downloading Docsify assets"

CDN="https://cdn.jsdelivr.net/npm"

fetch() {
  local url="$1" dest="$2"
  curl -sL --fail "$url" -o "$dest" || die "Failed to download: $url"
  ok "$dest"
}

# Core Docsify, search plugin, and theme
fetch "${CDN}/docsify@${DOCSIFY_VERSION}/lib/docsify.min.js"         assets/js/docsify.min.js
fetch "${CDN}/docsify@${DOCSIFY_VERSION}/lib/plugins/search.min.js"  assets/js/search.min.js
fetch "${CDN}/docsify@${DOCSIFY_VERSION}/themes/vue.css"             assets/css/vue.css

# Copy-to-clipboard plugin (injects its own CSS — no separate stylesheet needed)
fetch "${CDN}/docsify-copy-code@${COPY_CODE_VERSION}/dist/docsify-copy-code.min.js"  assets/js/docsify-copy-code.min.js

# Extra Prism languages. Docsify already bundles Prism core plus html/css/clike/
# javascript, so we only add the languages it does NOT ship. Never download
# prism-core here — a standalone core replaces Docsify's Prism and silently breaks
# highlighting for every language loaded after it.
fetch "${CDN}/prismjs@${PRISM_VERSION}/components/prism-bash.min.js"    assets/js/prism-bash.min.js
fetch "${CDN}/prismjs@${PRISM_VERSION}/components/prism-yaml.min.js"    assets/js/prism-yaml.min.js
fetch "${CDN}/prismjs@${PRISM_VERSION}/components/prism-python.min.js"  assets/js/prism-python.min.js
fetch "${CDN}/prismjs@${PRISM_VERSION}/components/prism-r.min.js"       assets/js/prism-r.min.js

# Math: docsify-katex bundles the KaTeX renderer (version coupling is documented in the
# Configuration block above). KaTeX's stylesheet loads its fonts from ./fonts/ beside it,
# so the woff2 files go in assets/css/fonts/. Stylesheet + fonts are pinned to the bundled
# KaTeX (KATEX_VERSION).
fetch "${CDN}/docsify-katex@${DOCSIFY_KATEX_VERSION}/dist/docsify-katex.js"   assets/js/docsify-katex.js
fetch "${CDN}/katex@${KATEX_VERSION}/dist/katex.min.css"   assets/css/katex.min.css
# Read the woff2 font list out of the stylesheet, then download each. Guard against an
# empty match: a future KaTeX bump could change the CSS format, which would otherwise
# silently ship a site whose math renders without fonts.
mapfile -t katex_fonts < <(grep -oE 'fonts/KaTeX_[^)]+\.woff2' assets/css/katex.min.css | sort -u)
[[ ${#katex_fonts[@]} -gt 0 ]] \
  || die "No KaTeX woff2 fonts found in katex.min.css; the CSS format may have changed for katex@${KATEX_VERSION}."
for f in "${katex_fonts[@]}"; do
  curl -sL --fail "${CDN}/katex@${KATEX_VERSION}/dist/$f" -o "assets/css/$f" \
    || die "Failed to download: $f"
done
ok "assets/css/fonts/ (${#katex_fonts[@]} KaTeX woff2 files)"

# UX plugins — each loads after docsify; alerts/tabs/pagination inject their own CSS.
fetch "${CDN}/docsify-plugin-flexible-alerts@${FLEXIBLE_ALERTS_VERSION}/dist/docsify-plugin-flexible-alerts.min.js"  assets/js/docsify-plugin-flexible-alerts.min.js
fetch "${CDN}/docsify-tabs@${TABS_VERSION}/dist/docsify-tabs.min.js"               assets/js/docsify-tabs.min.js
fetch "${CDN}/docsify-pagination@${PAGINATION_VERSION}/dist/docsify-pagination.min.js"  assets/js/docsify-pagination.min.js
# Image zoom: medium-zoom is a generic library (a hook in index.html applies it) + its CSS
fetch "${CDN}/medium-zoom@${MEDIUM_ZOOM_VERSION}/dist/medium-zoom.min.js"                 assets/js/medium-zoom.min.js
fetch "${CDN}/medium-zoom@${MEDIUM_ZOOM_VERSION}/dist/style.css"                          assets/css/medium-zoom.css
# Collapsible sidebar — needs its own stylesheet
fetch "${CDN}/docsify-sidebar-collapse@${SIDEBAR_COLLAPSE_VERSION}/dist/docsify-sidebar-collapse.min.js"  assets/js/docsify-sidebar-collapse.min.js
fetch "${CDN}/docsify-sidebar-collapse@${SIDEBAR_COLLAPSE_VERSION}/dist/sidebar.min.css"       assets/css/sidebar.min.css

# Diagrams: Mermaid (self-contained, ~3 MB) + docsify-mermaid, which turns ```mermaid
# fenced blocks into diagrams (it uses Mermaid v11's run() API).
fetch "${CDN}/mermaid@${MERMAID_VERSION}/dist/mermaid.min.js"                       assets/js/mermaid.min.js
fetch "${CDN}/docsify-mermaid@${DOCSIFY_MERMAID_VERSION}/dist/docsify-mermaid.js"             assets/js/docsify-mermaid.js

# Record SHA-256 checksums of every downloaded asset. Commit assets/ together with this
# manifest to rebuild without jsDelivr and to verify integrity later with:
#   (cd assets && sha256sum -c SHA256SUMS)
( cd assets && find . -type f ! -name SHA256SUMS \( -name '*.js' -o -name '*.css' -o -name '*.woff2' \) \
    -print0 | sort -z | xargs -0 sha256sum > SHA256SUMS )
ok "assets/SHA256SUMS ($(wc -l < assets/SHA256SUMS) files)"

# ── Step 3: index.html ──────────────────────────────────────────────────────────
step "Step 3 — Creating index.html"

# The heredoc delimiter is single-quoted ('HTML') so the shell does not expand
# $docsify inside the template.
cat > index.html << 'HTML'
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>My Docs</title>
  <link rel="stylesheet" href="assets/css/vue.css">
  <link rel="stylesheet" href="assets/css/katex.min.css">
  <link rel="stylesheet" href="assets/css/sidebar.min.css">
  <link rel="stylesheet" href="assets/css/medium-zoom.css">
</head>
<body>
  <div id="app"></div>
  <script>
    window.$docsify = {
      name: 'My Docs',
      loadSidebar: true,   // enables _sidebar.md
      subMaxLevel: 2,      // auto-generate H2 entries in sidebar
      search: 'auto',      // enables the search plugin
      plugins: [
        // medium-zoom: click an image in the content to enlarge it
        function (hook) {
          hook.doneEach(function () {
            if (window.mediumZoom) mediumZoom('.markdown-section img');
          });
        }
      ]
    }
  </script>
  <script src="assets/js/docsify.min.js"></script>
  <script src="assets/js/search.min.js"></script>
  <script src="assets/js/docsify-copy-code.min.js"></script>
  <script src="assets/js/docsify-katex.js"></script>

  <!-- Extra Prism languages — Docsify bundles Prism core + html/css/js. Load after docsify. -->
  <script src="assets/js/prism-bash.min.js"></script>
  <script src="assets/js/prism-yaml.min.js"></script>
  <script src="assets/js/prism-python.min.js"></script>
  <script src="assets/js/prism-r.min.js"></script>

  <!-- UX plugins (callout boxes, tabs, prev/next pagination, image zoom, collapsible sidebar) -->
  <script src="assets/js/docsify-plugin-flexible-alerts.min.js"></script>
  <script src="assets/js/docsify-tabs.min.js"></script>
  <script src="assets/js/docsify-pagination.min.js"></script>
  <script src="assets/js/medium-zoom.min.js"></script>
  <script src="assets/js/docsify-sidebar-collapse.min.js"></script>

  <!-- Diagrams: Mermaid + docsify integration (disable Mermaid's own auto-run) -->
  <script src="assets/js/mermaid.min.js"></script>
  <script src="assets/js/docsify-mermaid.js"></script>
  <script>mermaid.initialize({ startOnLoad: false });</script>
</body>
</html>
HTML

ok "index.html"

# ── Step 4: Boilerplate content ─────────────────────────────────────────────────
step "Step 4 — Boilerplate content (created only if missing)"

# Write the heredoc on stdin to $1, but never clobber an existing file — so
# re-running refreshes the assets and index.html without touching your content.
write_boilerplate() {
  local dest="$1"
  local content
  content="$(cat)"
  if [[ -e "$dest" ]]; then
    skip "$dest (exists — left unchanged)"
  else
    printf '%s\n' "$content" > "$dest"
    ok "$dest"
  fi
}

write_boilerplate README.md << 'EOF'
# Welcome

This is the home page of your documentation site.
Edit `README.md` to replace this content.

## Quick Links

- [Getting Started](getting-started.md)
EOF

write_boilerplate _sidebar.md << 'EOF'
- [Home](/)
- [Getting Started](getting-started.md)
EOF

write_boilerplate getting-started.md << 'EOF'
# Getting Started

This is an example page. Replace this content with your own documentation.

## Section One

Write your content here using standard Markdown.

## Section Two

Docsify will automatically generate sidebar anchors for H2 headings
when `subMaxLevel: 2` is set in `index.html`.
EOF

# ── Step 5: Permissions ─────────────────────────────────────────────────────────
step "Step 5 — Setting file permissions"

# Prune dotfiles/dotdirs so a docroot that is a Git repo keeps its .git/ perms intact.
find . -path './.*' -prune -o -type f -exec chmod 644 {} \;
find . -path './.*' -prune -o -type d -exec chmod 755 {} \;
ok "Files: 644 | Directories: 755 (dotfiles left untouched)"

# ── Verify ───────────────────────────────────────────────────────────────────────
step "Verifying file layout"

find . -not -path '*/\.*' -not -path './assets/css/fonts*' | sort
echo "./assets/css/fonts/  ($(ls -1 assets/css/fonts 2>/dev/null | wc -l) KaTeX woff2 files)"

# ── Done ─────────────────────────────────────────────────────────────────────────
echo ""
echo -e "${GREEN}${BOLD}Setup complete.${NC}"
echo -e "Open your site in a browser to verify."
echo ""
echo -e "Syntax highlighting: html, css, and javascript are built into Docsify;"
echo -e "this setup adds bash, yaml, python, and r. To add more languages, download"
echo -e "additional prism-<lang>.min.js files into assets/js/ and add their <script>"
echo -e "tags to index.html. Copy-to-clipboard buttons are enabled on all code blocks."
echo -e "LaTeX math renders via KaTeX (inline \$...\$ and block \$\$...\$\$)."
echo 'Mermaid diagrams render from ```mermaid fenced blocks.'
echo 'UX: callout boxes (> [!NOTE]), tabs, prev/next pagination, image zoom, and a'
echo 'collapsible sidebar are enabled.'
echo ""
echo -e "Asset versions are pinned and checksummed in assets/SHA256SUMS"
echo -e "(verify any time with:  cd assets && sha256sum -c SHA256SUMS)."
echo -e "Commit assets/ to Git to rebuild without depending on jsDelivr."