#!/bin/bash
# Run a command, or fall back to a web search if it isn't one.
# fuzzel --dmenu prints the typed string as-is when nothing matches,
# which is what makes the search fallback work.

browser_app_id="google-chrome"
search_url="https://duckduckgo.com/?q="

# Executables in PATH. Deliberately not `compgen -c`: that also lists shell
# builtins and keywords (cd, alias, if, ...), which `command -v` reports as
# found but `exec` cannot run.
list_path_bins() {
    local IFS=: dir file
    for dir in $PATH; do
        [[ -d $dir ]] || continue
        for file in "$dir"/*; do
            [[ -f $file && -x $file ]] && printf '%s\n' "${file##*/}"
        done
    done | sort -u
}

result=$(list_path_bins | fuzzel --dmenu)
[[ -z $result ]] && exit 0

# type -P looks only at PATH, so builtins and keywords correctly fall through
# to the search branch instead of failing silently in exec.
if type -P "${result%% *}" >/dev/null 2>&1; then
    exec $result
fi

query=$(jq -rn --arg q "$result" '$q|@uri')
xdg-open "$search_url$query" &

# Wait for the browser window instead of guessing at a fixed sleep: a cold
# start takes well over half a second, while an already-running Chrome is
# ready almost immediately.
for _ in $(seq 40); do
    if swaymsg -t get_tree |
        jq -e --arg id "$browser_app_id" \
            'recurse(.nodes[]?, .floating_nodes[]?) | select(.app_id == $id)' >/dev/null; then
        swaymsg "[app_id=\"$browser_app_id\"] focus" >/dev/null
        exit 0
    fi
    sleep 0.05
done