#!/bin/sh

# build-code-server.sh
# downloads the official code-server release and packages it as a portable AppImage.
# the resulting AppImage bundles everything and requires no system installation.

# usage:
#   sh build-code-server.sh
#   PKGVER=4.420.0 sh build-code-server.sh    # override version
#
# running the output AppImage:
#   regular:  ./code-server-VERSION-ARCH.AppImage [args]
#   docker:   APPIMAGE_EXTRACT_AND_RUN=1 ./code-server-VERSION-ARCH.AppImage [args]

set -e

PKGVER="${PKGVER:-4.118.0}"
PKGNAME="code-server"
GITHUB_URL="https://github.com/coder/code-server"

# - check required tools
for _cmd in curl tar; do
    if ! command -v "$_cmd" > /dev/null 2>&1; then
        printf 'error: required tool not found: %s\n' "$_cmd" >&2
        exit 1
    fi
done

# - detect host architecture
UNAME_ARCH="$(uname -m)"
case "$UNAME_ARCH" in
    x86_64)
        RELEASE_ARCH="amd64"
        ;;
    aarch64)
        RELEASE_ARCH="arm64"
        ;;
    *)
        printf 'error: unsupported architecture: %s\n' "$UNAME_ARCH" >&2
        exit 1
        ;;
esac

RELEASE_NAME="${PKGNAME}-${PKGVER}-linux-${RELEASE_ARCH}"
TARBALL="${RELEASE_NAME}.tar.gz"
TARBALL_URL="${GITHUB_URL}/releases/download/v${PKGVER}/${TARBALL}"
APPIMAGETOOL_URL="https://github.com/AppImage/AppImageKit/releases/download/continuous/appimagetool-${UNAME_ARCH}.AppImage"

# - icon urls: try versioned tag, fall back to main branch
ICON_URL="https://raw.githubusercontent.com/coder/code-server/v${PKGVER}/src/browser/media/pwa-icon-512.png"
ICON_FALLBACK_URL="https://raw.githubusercontent.com/coder/code-server/main/src/browser/media/pwa-icon-512.png"

OUTPUT_DIR="$(pwd)"
WORKDIR="$(mktemp -d)"
APPDIR="${WORKDIR}/AppDir"

# - always clean up temp workdir on exit
cleanup() {
    rm -rf "$WORKDIR"
}
trap cleanup EXIT INT TERM

printf '==> setting up build directory...\n'
mkdir -p \
    "${APPDIR}/usr/lib" \
    "${APPDIR}/usr/bin" \
    "${APPDIR}/usr/share/icons/hicolor/512x512/apps"

cd "$WORKDIR"

# - download the official pre-built release tarball (same source as PKGBUILD)
printf '==> downloading code-server v%s (%s)...\n' "$PKGVER" "$RELEASE_ARCH"
curl -fL --progress-bar -o "$TARBALL" "$TARBALL_URL"

printf '==> extracting tarball...\n'
tar -xzf "$TARBALL"

printf '==> populating AppDir...\n'
cp -a "${RELEASE_NAME}" "${APPDIR}/usr/lib/${PKGNAME}"

# - AppRun is the entrypoint; resolves paths relative to the AppImage mount
cat > "${APPDIR}/AppRun" << 'APPRUN_EOF'
#!/bin/sh
# apprun - entrypoint for code-server AppImage
SELF="$(readlink -f "$0")"
HERE="$(dirname "$SELF")"
export PATH="${HERE}/usr/bin:${PATH}"
exec "${HERE}/usr/lib/code-server/bin/code-server" "$@"
APPRUN_EOF
chmod +x "${APPDIR}/AppRun"

# - .desktop file is required by the AppImage spec
cat > "${APPDIR}/${PKGNAME}.desktop" << DESKTOP_EOF
[Desktop Entry]
Name=code-server
Comment=VS Code in the browser
Exec=code-server
Icon=code-server
Type=Application
Categories=Development;IDE;
DESKTOP_EOF

# - fetch icon; fall back to main branch if the versioned tag path differs
printf '==> downloading icon...\n'
if ! curl -fsSL -o "${APPDIR}/usr/share/icons/hicolor/512x512/apps/${PKGNAME}.png" "$ICON_URL"; then
    printf '    versioned icon not found, trying main branch...\n'
    curl -fL --progress-bar \
        -o "${APPDIR}/usr/share/icons/hicolor/512x512/apps/${PKGNAME}.png" \
        "$ICON_FALLBACK_URL"
fi

# - appimage spec also requires the icon at the AppDir root
cp "${APPDIR}/usr/share/icons/hicolor/512x512/apps/${PKGNAME}.png" \
   "${APPDIR}/${PKGNAME}.png"

# - download appimagetool (itself an AppImage; APPIMAGE_EXTRACT_AND_RUN avoids FUSE dependency)
printf '==> downloading appimagetool (%s)...\n' "$UNAME_ARCH"
curl -fL --progress-bar -o "${WORKDIR}/appimagetool" "$APPIMAGETOOL_URL"
chmod +x "${WORKDIR}/appimagetool"

# - build the AppImage
# - APPIMAGE_EXTRACT_AND_RUN=1 lets appimagetool run without FUSE (required in Docker)
# - ARCH must be set so appimagetool embeds the correct ELF architecture tag
OUTPUT="${OUTPUT_DIR}/${PKGNAME}-${PKGVER}-${UNAME_ARCH}.AppImage"
printf '==> building AppImage...\n'
ARCH="$UNAME_ARCH" APPIMAGE_EXTRACT_AND_RUN=1 \
    "${WORKDIR}/appimagetool" --comp gzip \
    "${APPDIR}" "${OUTPUT}"

chmod +x "${OUTPUT}"

printf '\n==> done!\n'
printf '    output: %s\n\n' "$OUTPUT"
printf 'usage:\n'
printf '  regular system:   ./%s-%s-%s.AppImage\n' "$PKGNAME" "$PKGVER" "$UNAME_ARCH"
printf '  docker/no-fuse:   APPIMAGE_EXTRACT_AND_RUN=1 ./%s-%s-%s.AppImage\n' "$PKGNAME" "$PKGVER" "$UNAME_ARCH"

printf '\nmove %s to /opt/code-server-appimage/ within your environment and use the code-server wrapper script to run it\n\n' "$OUTPUT"