Make use of alacritty include functionality

Alacritty processor will now add the colorscheme via include statement
in the original configuration file instead of adding the theme directly
to the file.

theme_alacritty

@@ -25,6 +25,7 @@ theme="$3"
 permanent="$4"
 
 alacritty_conf="$HOME/.config/alacritty/alacritty.yml"
+include_conf="$HOME/.config/alacritty/colorscheme.yml"
 
 ## Main Entrypoint
 #
@@ -54,6 +55,7 @@ main() {
 #  Makes sure that if any application instance is
 #  currently running, it switches to new theme.
 theme() {
+  # TODO also do through include file
   dbg_msg $app "Setting up live config reload"
   if grep -qe '^live_config_reload:.*false' "$alacritty_conf"; then
     sed -e 's/^live_config_reload:.*false/^live_config_reload: true/gm'
@@ -61,6 +63,8 @@ theme() {
   else
     dbg_msg $app "Live config reload already enabled"
   fi
+  dbg_msg $app "Touching alacritty config"
+  touch "$alacritty_conf"
 }
 
 ## Theme setter
@@ -70,45 +74,47 @@ theme() {
 save() {
   dbg_msg $app "Saving theme"
 
-  # following format:
-  # '# Base16 [theme name] - alacritty color config'
-  # from which it will delete everything until it finds a line:
-  # '# Base16End [theme name] - alacritty color config'
-  startline="$(grep -ne '^# Base16 .*- alacritty color config$' "$alacritty_conf" | cut -f1 -d:)"
-  endline="$(grep -ne '^# Base16End .*- alacritty color config$' "$alacritty_conf" | cut -f1 -d:)"
+  # replace colorscheme.yml content with new one
+  cp "$tfile" "$include_conf"
+  dbg_msg $app "Wrote theme file to $include_conf"
 
-  tmpfile="$alacritty_conf.tmp"
-  tmptheme="$alacritty_conf.thm.tmp"
+  # find import line in alacritty conf
+  if grep -qe '^import:' "$alacritty_conf"; then
 
-  if [[ -n "$startline" && -z "$endline" ]] || [[ -z "$startline" && -n "$endline" ]] || [[ "$startline" -gt "$endline" ]]; then
-    dbg_msg $app "error" "Base 16 Pattern not correctly recognized in file: $alacritty_conf. Please make sure pattern begins with # Base 16 and ends with # Base 16end and only exists once in the file. No changes to file made."
-
-  elif [[ -z "$startline" && -z "$endline" ]]; then
-    # TODO on first run automatically replace ^colors: line and any subsequent indented lines with commented versions and create colors: *colorscheme programatically
-    dbg_msg $app "warn" "No previous Base16 pattern found in file: $alacritty_conf. If this is your first time running the processor, please manually remove any previous colors: settings and replace with 'colors: *colorscheme' instead."
-    cat "$alacritty_conf" >"$tmpfile" || exit 1
+    # find first line containing imports (actual - file.yml line)
+    local import_first_line
+    import_first_line=$(grep -ne '^import:' "$alacritty_conf" | cut -f1 -d:)
+    import_first_line=$((import_first_line + 1))
+    # find last line containing imports (actual - file.yml line)
+    local import_last_line
+    import_last_line=$(tail -n+"$import_first_line" "$alacritty_conf" | grep -nve '[[:space:]]*-' | head -n1 | cut -f1 -d:)
+    # extract imports
+    local imports
+    imports=$(tail -n+$import_first_line "$alacritty_conf" | head -n $((import_first_line + import_last_line)))
 
+    if echo "$imports" | grep -qe "$(basename "$include_conf")$"; then
+      dbg_msg $app "Already correctly imports theme file"
+      return
     else
-    # remove old lines of any base16 theme
-    sed -e "$startline,$endline d" "$alacritty_conf" >"$tmpfile" || exit 1
-
+      dbg_msg $app "Creating config backup file"
+      tmpfile="$alacritty_conf.tmp"
+      cp "$alacritty_conf" "$tmpfile"
+      dbg_msg $app "Including theme file in imports"
+      (
+        head -n $((import_first_line - 1)) "$tmpfile"
+        echo "  - ${include_conf#${HOME}/}"
+        tail -n +$import_first_line "$tmpfile"
+      ) >"$alacritty_conf"
+      dbg_msg $app "Removing config backup file"
+      rm "$tmpfile"
+    fi
+  # no imports yet, append to end of file
+  else
+    # we remove the home prefix from the absolute path since alacritty
+    # can deal with an inclusion in the form of .config/alacritty/colorscheme.yml
+    printf "\nimport:\n  - %s\n" "${include_conf#${HOME}/}" >>"$alacritty_conf"
   fi
 
-  # make sure we're not adding this line twice
-  sed -e 's/^draw_bold_text_with_bright_colors:/# draw_bold_text_with_bright_colors:/' "$tmpfile" >"$tmpfile.tmp"
-  mv "$tmpfile.tmp" "$tmpfile"
-
-  # fix template theme name key for easier inclusion
-  sed -e "s/^colors:/$theme: \&colorscheme/" "$tfile" >"$tmptheme" || exit 1
-  echo "# Base16End $theme - alacritty color config" >>"$tmptheme"
-
-  # combine both into final config file
-  # replace original file with new colorscheme-added version
-  cat "$tmptheme" "$tmpfile" >"$alacritty_conf"
-
-  rm "$tmptheme" "$tmpfile"
-
-  dbg_msg $app "Saved theme to $alacritty_conf"
 }
 
 # Safe sourcing: https://stackoverflow.com/a/12694189