#!/usr/bin/env bash

set -e

# Ensure the ~/.local/bin directory exists so we can download things into it.
LOCAL_BIN="$HOME/.local/bin"
mkdir -p "$LOCAL_BIN"

# Extract the short commit baked into the linuxdeploy AppImage.
appimage_commit() {
  "$1" --version 2>&1 | grep -oE "git commit ID [0-9a-f]{7,40}" | cut -d' ' -f4
}

# A helper function to download an architecture-dependent AppImage and install
# it in ~/.local/bin.
#
# Usage:
#   download_appimage $BINARY_NAME $VERSION $COMMIT $REPO_URL
#
# Args:
#   BINARY_NAME: The name of the AppImage-bundled binary we want to download,
#                e.g.: "linuxdeploy".
#   VERSION:     The upstream release tag.
#   COMMIT:      The (short) commit SHA the release tag points at; used to
#                verify the cached binary matches the pinned version.
#   REPO_URL:    The URL of the GitHub repository hosting the release.
download_appimage() {
  BINARY_NAME="$1"
  VERSION="$2"
  COMMIT="$3"
  REPO_URL="$4"

  APPIMAGE_NAME="$BINARY_NAME-$(uname -m).AppImage"
  APPIMAGE_PATH="$LOCAL_BIN/$APPIMAGE_NAME"

  if [ -x "$APPIMAGE_PATH" ] && [ "$(appimage_commit "$APPIMAGE_PATH")" = "$COMMIT" ]; then
    echo "✅ Found $APPIMAGE_NAME in $LOCAL_BIN."
  else
    APPIMAGE_RELEASE_URL="$REPO_URL/releases/download/$VERSION/$APPIMAGE_NAME"
    echo "⬇️ Downloading $APPIMAGE_RELEASE_URL..."
    curl -fL "$APPIMAGE_RELEASE_URL" --output "$APPIMAGE_PATH"
    chmod +x "$APPIMAGE_PATH"
  fi

  # Create a symlink so we can invoke it like a normal binary.
  ln -sf "$APPIMAGE_PATH" "$LOCAL_BIN/$BINARY_NAME"
}

# Install linuxdeploy, a helper for constructing an AppDir (and then invoking
# appimagetool).
download_appimage "linuxdeploy" "1-alpha-20251107-1" "cc7b864" \
  "https://github.com/linuxdeploy/linuxdeploy"

if [ ! -x "$(which linuxdeploy)" ]; then
  echo -e "⚠️  ${red}Please make sure that \"$LOCAL_BIN\" is on your PATH, otherwise some scripts may not work.${reset}"
fi