#!/usr/bin/env bash
# ============================================================================
# prerender-static.sh — build aac.transaction.science as a self-contained
# static site.
#
# AAC ships as a static CSR-hydrate SPA, but it's a Leptos SSR app: the
# index.html the browser loads is the SSR server's *rendered* output (it carries
# the hydration island markers and the pre-rendered board). A plain
# `cargo leptos build` never emits that index.html, and it doesn't copy the
# PWA assets that live in `static/`. This script closes both gaps and makes the
# result safe to cache forever:
#
#   build   -> target/site/{pkg/, icons/}             (cargo-leptos)
#   render  -> target/site/index.html                 (capture SSR `/`)
#   hash    -> pkg/aac-web.<sha256:12>.{js,wasm,css}  (and rewrite references)
#   worker  -> target/site/sw.js                      (static/sw.js + precache list)
#
# Output: a self-contained `target/site/` ready to rsync to prod. Deploy it with
# no_cache_bust — the names are already content-hashed, and the service worker
# lists them. Idempotent.
#
# Hosting under a sub-path, or under another name, is a build-time choice; see
# AAC_BASE_PATH, AAC_SW_URL, AAC_APP_TITLE and AAC_HIDE_ENERGY in
# crates/aac-web/src/app.rs. This script builds the root-mounted default.
# ============================================================================
set -euo pipefail
cd "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

PORT="${AAC_PRERENDER_PORT:-39207}"
SITE="target/site"
CACHE="${XDG_CACHE_HOME:-$HOME/.cache}/aac-rs"

# wasm-bindgen's CLI must match the crate version exactly (Cargo.toml pins it).
# Use a private copy of the right version rather than the machine's global one.
WBG_VER="$(awk '/^name = "wasm-bindgen"$/{getline; gsub(/version = |"/, ""); print; exit}' Cargo.lock)"
if ! wasm-bindgen --version 2>/dev/null | grep -qx "wasm-bindgen $WBG_VER"; then
  WBG_ROOT="$CACHE/wasm-bindgen-$WBG_VER"
  if [ ! -x "$WBG_ROOT/bin/wasm-bindgen" ]; then
    echo "▸ installing wasm-bindgen-cli $WBG_VER into $WBG_ROOT"
    cargo install --quiet --locked --root "$WBG_ROOT" wasm-bindgen-cli --version "$WBG_VER"
  fi
  export PATH="$WBG_ROOT/bin:$PATH"
fi

echo "▸ cargo leptos build --release"
rm -rf "$SITE/pkg"
cargo leptos build --release
find "$SITE/pkg" -name '*.d.ts' -delete

echo "▸ starting SSR server on 127.0.0.1:$PORT to prerender /"
LOG="$(mktemp)"
LEPTOS_OUTPUT_NAME=aac-web \
LEPTOS_SITE_ROOT="$SITE" \
LEPTOS_SITE_PKG_DIR=pkg \
LEPTOS_SITE_ADDR="127.0.0.1:$PORT" \
LEPTOS_ENV=PROD \
  target/release/aac-web > "$LOG" 2>&1 &
SRV=$!
trap 'kill "$SRV" 2>/dev/null || true' EXIT

# Wait for the listener (up to ~30s).
ready=false
for _ in $(seq 1 120); do
  if curl -sf "http://127.0.0.1:$PORT/" -o /dev/null 2>/dev/null; then ready=true; break; fi
  sleep 0.25
done
if ! $ready; then
  echo "✗ SSR server did not come up; log:" >&2; tail -5 "$LOG" >&2; exit 1
fi

echo "▸ capturing rendered / -> $SITE/index.html"
curl -sf "http://127.0.0.1:$PORT/" -o "$SITE/index.html"

kill "$SRV" 2>/dev/null || true
trap - EXIT

# Sanity-check the capture is the hydrating SSR shell, not an error page.
test -s "$SITE/index.html"
grep -q 'mod.hydrate' "$SITE/index.html" || { echo "✗ captured index.html is not the hydrating shell" >&2; exit 1; }
grep -q '<title>AAC' "$SITE/index.html" || { echo "✗ captured index.html missing expected title" >&2; exit 1; }

echo "▸ content-hashing pkg/"
hash12() { shasum -a 256 "$1" | cut -c1-12; }
# Portable in-place sed (BSD and GNU disagree about -i):  sed_i <args…> <file>
sed_i() { local f="${!#}"; sed "${@:1:$#-1}" "$f" > "$f.tmp" && mv "$f.tmp" "$f"; }
P="$SITE/pkg"
[ -f "$P/aac-web_bg.wasm" ] || mv "$P/aac-web.wasm" "$P/aac-web_bg.wasm"
W="$(hash12 "$P/aac-web_bg.wasm")";  mv "$P/aac-web_bg.wasm" "$P/aac-web.$W.wasm"
C="$(hash12 "$P/aac-web.css")";      mv "$P/aac-web.css" "$P/aac-web.$C.css"
# The glue may name its wasm; point it at the hashed file before hashing the glue.
sed_i -e "s#aac-web_bg\\.wasm#aac-web.$W.wasm#g" -e "s#aac-web\\.wasm#aac-web.$W.wasm#g" "$P/aac-web.js"
J="$(hash12 "$P/aac-web.js")";       mv "$P/aac-web.js" "$P/aac-web.$J.js"
sed_i \
  -e "s#/pkg/aac-web_bg\\.wasm#/pkg/aac-web.$W.wasm#g" \
  -e "s#/pkg/aac-web\\.wasm#/pkg/aac-web.$W.wasm#g" \
  -e "s#/pkg/aac-web\\.js#/pkg/aac-web.$J.js#g" \
  -e "s#/pkg/aac-web\\.css#/pkg/aac-web.$C.css#g" \
  "$SITE/index.html"
# Leptos's hydration loader builds its URLs from arguments:
#   (root, pkg_path, output_name, wasm_output_name)
LOADER='("", "pkg", "aac-web", "aac-web")'
grep -qF "$LOADER" "$SITE/index.html" || { echo "✗ hydration loader call not found — has Leptos changed its loader?" >&2; exit 1; }
sed_i "s#(\"\", \"pkg\", \"aac-web\", \"aac-web\")#(\"\", \"pkg\", \"aac-web.$J\", \"aac-web.$W\")#" "$SITE/index.html"
for f in "aac-web.$W.wasm" "aac-web.$J.js" "aac-web.$C.css" "\"aac-web.$J\", \"aac-web.$W\""; do
  grep -q "$f" "$SITE/index.html" || { echo "✗ index.html does not reference $f" >&2; exit 1; }
done

echo "▸ bundling PWA assets and the service worker"
cp crates/aac-web/static/manifest.json "$SITE/manifest.json"
# Precache: the shell, the manifest, every file in pkg/ (including wasm-bindgen
# snippets such as the eye-tracking loader) and the icons.
PRECACHE=("/" "/manifest.json")
while IFS= read -r f; do PRECACHE+=("/${f#"$SITE"/}"); done < <(find "$SITE/pkg" "$SITE/icons" -type f | LC_ALL=C sort)
VERSION="$(for u in "${PRECACHE[@]}"; do
  if [ "$u" = "/" ]; then f="$SITE/index.html"; else f="$SITE$u"; fi
  printf '%s %s\n' "$u" "$(shasum -a 256 "$f" | cut -c1-64)"
done | shasum -a 256 | cut -c1-12)"
LIST="[$(printf '"%s",' "${PRECACHE[@]}" | sed 's/,$//')]"
sed -e "s#__VERSION__#$VERSION#" -e "s#__PRECACHE_URLS__#$LIST#" crates/aac-web/static/sw.js > "$SITE/sw.js"
grep -q "__" "$SITE/sw.js" && grep -nE "__[A-Z_]+__" "$SITE/sw.js" && { echo "✗ sw.js has an unfilled placeholder" >&2; exit 1; }

echo "✓ self-contained dist ready at $SITE/ (service worker $VERSION, ${#PRECACHE[@]} files precached)"
ls -1 "$SITE" "$SITE/pkg"