#!/bin/bash

# omarchy:summary=Apply an Omarchy theme
# omarchy:args=<theme-name>
# omarchy:examples=omarchy theme list | omarchy theme set "Tokyo Night"

if [[ -z $1 ]]; then
  echo "Usage: omarchy-theme-set <theme-name>"
  exit 1
fi

CURRENT_THEME_PATH="$HOME/.local/state/omarchy/current/theme"
NEXT_THEME_PATH="$HOME/.local/state/omarchy/current/next-theme"
CURRENT_BACKGROUND_LINK="$HOME/.local/state/omarchy/current/background"
BACKGROUND_TRANSITION_CACHE="$HOME/.cache/omarchy/background-transitions"
THEME_SET_LOCK="${XDG_RUNTIME_DIR:-/tmp}/omarchy-theme-set.lock"
USER_THEMES_PATH="$HOME/.config/omarchy/themes"
OMARCHY_THEMES_PATH="$OMARCHY_PATH/themes"

run_parallel() {
  local pid
  local pids=()

  for command in "$@"; do
    bash -lc "$command" &
    pids+=("$!")
  done

  for pid in "${pids[@]}"; do
    wait "$pid"
  done
}

shell_ipc() {
  timeout 2 omarchy-shell "$@" >/dev/null 2>&1
}

snapshot_background_path() {
  local background="$1"
  local name="$2"
  local snapshot extension

  [[ -f $background ]] || return

  mkdir -p "$BACKGROUND_TRANSITION_CACHE"
  extension=${background##*.}
  snapshot="$BACKGROUND_TRANSITION_CACHE/$name-$$.$extension"
  ln "$background" "$snapshot" 2>/dev/null || cp "$background" "$snapshot"
  echo "$snapshot"
}

snapshot_current_background() {
  local current_background

  current_background=$(readlink -f "$CURRENT_BACKGROUND_LINK" 2>/dev/null || true)
  snapshot_background_path "$current_background" "previous"
}

choose_theme_background() {
  local backgrounds=()
  local current_background index next_index i

  CHOSEN_THEME_BACKGROUND=""
  mapfile -d '' -t backgrounds < <(
    find -L "$HOME/.config/omarchy/backgrounds/$THEME_NAME/" "$CURRENT_THEME_PATH/backgrounds/" -maxdepth 1 -type f \
      \( -iname '*.jpg' -o -iname '*.jpeg' -o -iname '*.png' -o -iname '*.gif' -o -iname '*.bmp' -o -iname '*.webp' \) \
      -print0 2>/dev/null | sort -z
  )

  (( ${#backgrounds[@]} > 0 )) || return 1

  current_background=$(readlink "$CURRENT_BACKGROUND_LINK" 2>/dev/null || true)
  index=-1
  for i in "${!backgrounds[@]}"; do
    if [[ ${backgrounds[$i]} == $current_background ]]; then
      index=$i
      break
    fi
  done

  if (( index == -1 )); then
    CHOSEN_THEME_BACKGROUND="${backgrounds[0]}"
  else
    next_index=$(((index + 1) % ${#backgrounds[@]}))
    CHOSEN_THEME_BACKGROUND="${backgrounds[$next_index]}"
  fi
}

set_theme_background_link() {
  choose_theme_background || return 1
  ln -nsf "$CHOSEN_THEME_BACKGROUND" "$CURRENT_BACKGROUND_LINK"
}

set_theme_background() {
  local new_background new_background_snapshot

  if ! choose_theme_background; then
    omarchy-notification-send "No background was found for theme" -t 2000
    shell_ipc shell applyTheme "$colors_payload" "$shell_payload" || true
    return
  fi

  new_background="$CHOSEN_THEME_BACKGROUND"
  new_background_snapshot=$(snapshot_background_path "$new_background" "next")

  if [[ -f $OLD_BACKGROUND_SNAPSHOT && -f $new_background_snapshot ]]; then
    shell_ipc background themeTransition "$OLD_BACKGROUND_SNAPSHOT" "$new_background_snapshot" "$new_background" "$colors_payload" "$shell_payload" || \
      shell_ipc shell applyTheme "$colors_payload" "$shell_payload" || true
    (sleep 3; rm -f "$OLD_BACKGROUND_SNAPSHOT" "$new_background_snapshot") &
  elif [[ -f $new_background_snapshot ]]; then
    shell_ipc background themeTransition "" "$new_background_snapshot" "$new_background" "$colors_payload" "$shell_payload" || \
      shell_ipc shell applyTheme "$colors_payload" "$shell_payload" || true
    (sleep 3; rm -f "$new_background_snapshot") &
  else
    shell_ipc background themeTransition "$OLD_BACKGROUND_SNAPSHOT" "$new_background" "$new_background" "$colors_payload" "$shell_payload" || \
      shell_ipc shell applyTheme "$colors_payload" "$shell_payload" || true
    if [[ -f $OLD_BACKGROUND_SNAPSHOT ]]; then
      (sleep 3; rm -f "$OLD_BACKGROUND_SNAPSHOT") &
    fi
  fi

  ln -nsf "$new_background" "$CURRENT_BACKGROUND_LINK"
}

THEME_NAME=$(echo "$1" | sed -E 's/<[^>]+>//g' | tr '[:upper:]' '[:lower:]' | tr ' ' '-')
THEME_HEADLESS=0
if [[ ${OMARCHY_THEME_HEADLESS:-} == "1" || ${OMARCHY_THEME_OFFLINE:-} == "1" ]]; then
  THEME_HEADLESS=1
fi

if [[ ! -d $OMARCHY_THEMES_PATH/$THEME_NAME ]] && [[ ! -d $USER_THEMES_PATH/$THEME_NAME ]]; then
  echo "Theme '$THEME_NAME' does not exist"
  exit 1
fi

# Serialize theme changes. Theme switching rebuilds a shared next-theme staging
# directory and updates current theme/background symlinks; concurrent calls can
# otherwise race and make one selection appear to be ignored.
exec 9>"$THEME_SET_LOCK"
flock 9

# Setup clean next theme directory (for atomic theme config swapping)
rm -rf "$NEXT_THEME_PATH"
mkdir -p "$NEXT_THEME_PATH"

# Copy official theme first, then overlay user customizations on top
cp -r "$OMARCHY_THEMES_PATH/$THEME_NAME/"* "$NEXT_THEME_PATH/" 2>/dev/null
cp -r "$USER_THEMES_PATH/$THEME_NAME/"* "$NEXT_THEME_PATH/" 2>/dev/null

# Generate colors.toml from alacritty.toml if theme is missing colors.toml
if [[ ! -f $NEXT_THEME_PATH/colors.toml && -f $NEXT_THEME_PATH/alacritty.toml ]]; then
  omarchy-theme-colors-from-alacritty "$NEXT_THEME_PATH"
fi

# Generate dynamic configs
omarchy-theme-set-templates

OLD_BACKGROUND_SNAPSHOT=""
if [[ $THEME_HEADLESS != "1" && $OMARCHY_THEME_SKIP_BACKGROUND != "1" ]]; then
  OLD_BACKGROUND_SNAPSHOT=$(snapshot_current_background)
fi

# Swap next theme in as current
rm -rf "$CURRENT_THEME_PATH"
mv "$NEXT_THEME_PATH" "$CURRENT_THEME_PATH"

# Store theme name for reference
echo "$THEME_NAME" >"$HOME/.local/state/omarchy/current/theme.name"

# Make the running shell pick up the new palette immediately while the rest of
# the theme hooks run.
colors_payload=$([[ -f $CURRENT_THEME_PATH/colors.toml ]] && base64 -w 0 "$CURRENT_THEME_PATH/colors.toml")
shell_payload=$([[ -f $CURRENT_THEME_PATH/shell.toml ]] && base64 -w 0 "$CURRENT_THEME_PATH/shell.toml")
if [[ $THEME_HEADLESS == "1" ]]; then
  # No shell/session bus exists during ISO chroot finalization, but the first
  # real login still needs a current background symlink for omarchy-shell to
  # render.
  [[ $OMARCHY_THEME_SKIP_BACKGROUND == "1" ]] || set_theme_background_link || true
elif [[ $OMARCHY_THEME_SKIP_BACKGROUND == "1" ]]; then
  shell_ipc shell applyTheme "$colors_payload" "$shell_payload" || true
else
  set_theme_background
fi

# The shared staging/current symlinks are updated and the shell has accepted
# the transition. Let another theme selection queue only behind that critical
# section, not behind slower app-retint hooks and selector cache warmups.
flock -u 9

post_theme_commands=(
  omarchy-restart-terminal
  omarchy-restart-hyprctl
  omarchy-restart-btop
  omarchy-restart-opencode
  omarchy-restart-helix
  omarchy-theme-set-foot
  omarchy-theme-set-tmux
  omarchy-theme-set-gnome
  omarchy-theme-set-pi
  omarchy-theme-set-claude
  omarchy-theme-set-browser
  omarchy-theme-set-vscode
  omarchy-theme-set-obsidian
  omarchy-theme-set-keyboard
)

if [[ $THEME_HEADLESS != "1" ]]; then
  run_parallel "${post_theme_commands[@]}"

  # Call hook on theme set
  omarchy-hook theme-set "$THEME_NAME" >/dev/null

  # Warm selector caches after the theme is applied. The shell hot-reloads theme
  # colors/backgrounds, so keep the running instance alive and preload the picker
  # rows/selection to avoid first-open carousel settling after a theme change.
  omarchy-theme-switcher --preload >/dev/null 2>&1
  omarchy-theme-bg-cache >/dev/null 2>&1 &
fi