#!/usr/bin/bash

set -euo pipefail

base_dir="/mnt/data/media/share/pictures"
tmp_file="$(mktemp --suffix=.png)"
selection_file="$(mktemp)"

cleanup() {
    rm -f "$tmp_file" "$selection_file"
}
trap cleanup EXIT

trim_whitespace() {
    local value="$1"
    value="${value#"${value%%[![:space:]]*}"}"
    value="${value%"${value##*[![:space:]]}"}"
    printf '%s\n' "$value"
}

choose_destination_dir() {
    if [[ ! -d "$base_dir" ]] || ! mountpoint -q /mnt/data; then
        return 1
    fi

    {
        printf '/\n'
        find "$base_dir" -mindepth 1 -type d -printf '%P\n' | sort
    } > "$selection_file"

    if selected=$(wofi --dmenu --prompt 'Save screenshot path' < "$selection_file"); then
        if [[ -z "$selected" || "$selected" == "/" ]]; then
            printf '%s\n' "$base_dir"
        else
            printf '%s/%s\n' "$base_dir" "$selected"
        fi
        return 0
    fi

    printf '%s\n' "$base_dir"
}

choose_filename() {
    local default_name="screenshot"
    local selected=""

    if selected=$(printf '%s\n' "$default_name" | wofi --dmenu --prompt 'Save screenshot filename'); then
        selected=$(trim_whitespace "$selected")
    else
        selected="$default_name"
    fi

    if [[ -z "$selected" ]]; then
        selected="$default_name"
    fi

    selected="${selected%.png}"

    if [[ -z "$selected" ]]; then
        selected="$default_name"
    fi

    printf '%s\n' "$selected"
}

build_unique_path() {
    local destination_dir="$1"
    local file_stem="$2"
    local candidate="$destination_dir/$file_stem.png"
    local counter=1

    if [[ ! -e "$candidate" ]]; then
        printf '%s\n' "$candidate"
        return
    fi

    while [[ -e "$destination_dir/$file_stem-$counter.png" ]]; do
        counter=$((counter + 1))
    done

    printf '%s\n' "$destination_dir/$file_stem-$counter.png"
}

if ! region="$(slurp)"; then
    exit 0
fi

if ! grim -g "$region" - | swappy -f - -o "$tmp_file"; then
    exit 1
fi

wl-copy --type image/png < "$tmp_file"

if destination_dir="$(choose_destination_dir)"; then
    mkdir -p "$destination_dir"
    file_stem="$(choose_filename)"
    destination_path="$(build_unique_path "$destination_dir" "$file_stem")"
    cp "$tmp_file" "$destination_path"
    notify-send 'Screenshot saved' "$destination_path
Copied to clipboard"
else
    notify-send 'Screenshot copied' 'NAS picture share is not available; image copied to clipboard only'
fi