#!/bin/bash
#
# Purpose : Compile and install applications from compile.conf

CONF_FILE="$HOME/.local/share/HamPackServer/compile.conf"
TMP_DIR="/tmp/hampack-build"
VERSION_FILE="$HOME/.local/state/HamPackServer/.installed_versions"

# Get the installed version of an app
get_installed_version() {
  local app="$1"
  local gui="$2"

  # Skip --version check for GUI apps as it would launch them
  if [ "$gui" != "true" ]; then
    if command -v "$app" &> /dev/null; then
      local ver
      ver=$("$app" --version 2>&1 | grep -oP '\d+\.\d+[\.\d]*' | head -n1)
      if [ -n "$ver" ]; then
        echo "$ver"
        return
      fi
    fi
  fi

  # Fall back to version file
  if [ -f "$VERSION_FILE" ]; then
    local stored
    stored=$(grep "^$app=" "$VERSION_FILE" | cut -d'=' -f2)
    if [ -n "$stored" ]; then
      echo "$stored"
      return
    fi
  fi

  echo "unknown"
}

# Save installed version to version file
save_installed_version() {
  local app="$1"
  local version="$2"

  touch "$VERSION_FILE"

  if grep -q "^$app=" "$VERSION_FILE"; then
    sed -i "s/^$app=.*/$app=$version/" "$VERSION_FILE"
  else
    echo "$app=$version" >> "$VERSION_FILE"
  fi
}

# Ask the user whether to proceed when version can't be determined
ask_user_proceed() {
  local app="$1"
  local latest="$2"

  echo "Warning: could not determine installed version of $app."
  echo "compile.conf specifies version $latest."
  read -rp "Compile and install $app anyway? [y/N] " response
  [[ "$response" =~ ^[yY] ]]
}

# Check if an update is needed
needs_update() {
  local app="$1"
  local install_path="$2"
  local latest="$3"
  local gui="$4"

  # Not installed at all
  if ! command -v "$app" &> /dev/null && [ ! -f "$install_path" ]; then
    echo "  $app is not installed."
    return 0
  fi

  local installed
  installed=$(get_installed_version "$app" "$gui")

  if [ "$installed" = "unknown" ]; then
    if ask_user_proceed "$app" "$latest"; then
      return 0
    else
      return 1
    fi
  fi

  echo "  Installed version : $installed"
  echo "  Latest version    : $latest"

  if [ "$installed" = "$latest" ]; then
    echo "  $app is up to date, skipping."
    return 1
  fi

  echo "  Update available for $app."
  return 0
}

# Generate desktop file with absolute paths
generate_desktop() {
  local desktop="$1"
  local tmp_desktop="/tmp/$(basename "$desktop")"

  sed "s|\$HOME|$HOME|g" "$desktop" > "$tmp_desktop"
  echo "$tmp_desktop"
}

# Install desktop file if specified
install_desktop() {
  local desktop="$1"

  if [ -z "$desktop" ]; then
    return
  fi

  if [ ! -f "$desktop" ]; then
    echo "  Warning: desktop file $desktop not found, skipping."
    return
  fi

  echo "  Installing desktop file..."
  mkdir -p "$HOME/.local/share/applications"
  local resolved
  resolved=$(generate_desktop "$desktop")
  cp "$resolved" "$HOME/.local/share/applications/$(basename "$desktop")"
  chmod +x "$HOME/.local/share/applications/$(basename "$desktop")"
  rm -f "$resolved"
  echo "  Desktop file installed."
}

# Fetch source via git or wget
fetch_source() {
  local app="$1"
  local git_url="$2"
  local wget_url="$3"
  local src_dir="$TMP_DIR/$app"

  rm -rf "$src_dir"
  mkdir -p "$src_dir"

  if [ -n "$git_url" ]; then
    echo "  Cloning $git_url..."
    git clone "$git_url" "$src_dir"

  elif [ -n "$wget_url" ]; then
    echo "  Downloading $wget_url..."
    local filename="${wget_url##*/}"
    local filepath="$TMP_DIR/$filename"

    wget -q "$wget_url" -O "$filepath"

    echo "  Extracting $filename..."
    case "$filename" in
      *.zip)
        unzip -q "$filepath" -d "$src_dir"
        # If the zip extracted into a single subdirectory, flatten it
        local contents
        contents=$(ls -1 "$src_dir")
        local count
        count=$(echo "$contents" | wc -l)
        if [ "$count" -eq 1 ] && [ -d "$src_dir/$contents" ]; then
          echo "  Descending into $contents..."
          local inner="$src_dir/$contents"
          shopt -s dotglob
          mv "$inner"/* "$src_dir/"
          shopt -u dotglob
          rm -rf "$inner"
        fi
        ;;
      *.tar.gz|*.tgz)
        tar -xzf "$filepath" -C "$src_dir" --strip-components=1
        ;;
      *.tar.bz2)
        tar -xjf "$filepath" -C "$src_dir" --strip-components=1
        ;;
      *.tar.xz)
        tar -xJf "$filepath" -C "$src_dir" --strip-components=1
        ;;
      *)
        echo "  Error: unknown file type for $filename"
        exit 1
        ;;
    esac

    rm -f "$filepath"
  else
    echo "  Error: no git or wget URL specified for $app"
    exit 1
  fi
}

# cd into source directory and run steps
run_steps() {
  local app="$1"
  local steps="$2"
  local src_dir="$TMP_DIR/$app"

  if [ ! -d "$src_dir" ]; then
    echo "  Error: source directory $src_dir not found."
    exit 1
  fi

  echo "  Changing into $src_dir..."
  cd "$src_dir"

  echo "  Building $app..."
  IFS=',' read -ra step_list <<< "$steps"
  for step in "${step_list[@]}"; do
    step=$(echo "$step" | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')
    echo "  Running: $step"
    eval "$step"
  done
}

# Process a single app
process_app() {
  local app="$1"
  local git_url="$2"
  local wget_url="$3"
  local install_path="$4"
  local steps="$5"
  local version="$6"
  local desktop="$7"
  local gui="$8"

  echo ""
  echo "=== $app ==="

  # Check if already installed
  if command -v "$app" &> /dev/null || [ -f "$install_path" ]; then
    if [ -z "$version" ]; then
      echo "  $app is already installed, skipping."
      return
    fi
  fi

  if [ -z "$version" ]; then
    echo "  Warning: no version specified in compile.conf for $app."
    read -rp "  Compile and install $app anyway? [y/N] " response
    if [[ ! "$response" =~ ^[yY] ]]; then
      echo "  Skipping $app."
      return
    fi
  elif ! needs_update "$app" "$install_path" "$version" "$gui"; then
    return
  fi

  fetch_source "$app" "$git_url" "$wget_url"
  run_steps "$app" "$steps"
  install_desktop "$desktop"
  save_installed_version "$app" "$version"

  # Return to a safe directory after build
  cd "$HOME"

  echo "  $app $version installed successfully."
}

# Parse compile.conf and process each app
process_conf() {
  local app="" git_url="" wget_url="" install_path="" steps="" version="" desktop="" gui=""

  while IFS= read -r line || [ -n "$line" ]; do
    [[ -z "$line" || "$line" == \#* ]] && continue

    if [[ "$line" =~ ^\[(.+)\]$ ]]; then
      if [ -n "$app" ]; then
        process_app "$app" "$git_url" "$wget_url" "$install_path" "$steps" "$version" "$desktop" "$gui"
      fi
      app="${BASH_REMATCH[1]}"
      git_url="" wget_url="" install_path="" steps="" version="" desktop="" gui=""
      continue
    fi

    local key="${line%%=*}"
    local raw_value="${line#*=}"

    # Steps are stored raw so quotes and variables expand correctly at eval time
    if [ "$key" = "steps" ]; then
      steps="$raw_value"
      continue
    fi

    local value
    value=$(eval echo "$raw_value")

    case "$key" in
      git)     git_url="$value" ;;
      wget)    wget_url="$value" ;;
      install) install_path="$value" ;;
      version) version="$value" ;;
      desktop) desktop="$value" ;;
      gui)     gui="$value" ;;
    esac

  done < "$CONF_FILE"

  # Process the last app in the file
  if [ -n "$app" ]; then
    process_app "$app" "$git_url" "$wget_url" "$install_path" "$steps" "$version" "$desktop" "$gui"
  fi
}

# --- Main ---

if [ ! -f "$CONF_FILE" ]; then
  echo "Error: $CONF_FILE not found."
  exit 1
fi

mkdir -p "$TMP_DIR"
mkdir -p "$HOME/.local/state/HamPackServer"

echo "Starting HamPack source builds..."
process_conf

echo "Updating desktop database..."
update-desktop-database "$HOME/.local/share/applications/"

echo ""
echo "Cleaning up..."
rm -rf "$TMP_DIR"

echo "All done."