#!/usr/bin/env bash

VERBOSE=0
DIR=""

while [[ $# -gt 0 ]]; do
    case "$1" in
        -v|--verbose) VERBOSE=1 ;;
        *) DIR="$1" ;;
    esac
    shift
done

DIR="${DIR:-$HOME/Pictures}"
LOG=""
(( VERBOSE )) && LOG="/tmp/wallpaper-picker-$$.log"

IMAGES=()
while IFS= read -r -d '' f; do
    IMAGES+=("$f")
done < <(find "$DIR" -maxdepth 1 -type f \
    \( -iname '*.jpg' -o -iname '*.jpeg' -o -iname '*.png' \
       -o -iname '*.webp' -o -iname '*.bmp' -o -iname '*.gif' \
       -o -iname '*.avif' -o -iname '*.tiff' \) \
    -print0 | sort -z)

[[ ${#IMAGES[@]} -eq 0 ]] && { echo "No images found in $DIR"; exit 1; }

INDEX=0
CURRENT_WALLPAPER=""

vlog() { (( VERBOSE )) && printf '%s\n' "$*" >> "$LOG"; }

icat() { kitty +kitten icat --stdin=no --silent --transfer-mode=memory "$@" 2>/dev/null; }
clear_images() { icat --clear; }

draw() {
    local cols rows
    cols=$(tput cols); rows=$(tput lines)

    local gap=2
    local side_w=$(( cols * 18 / 100 ))
    local center_w=$(( cols - 2 * (side_w + gap) ))
    local center_x=$(( side_w + gap ))
    local next_x=$(( center_x + center_w + gap ))
    local img_h=$(( rows - 3 ))
    local n=${#IMAGES[@]}

    local prev=$(( (INDEX - 1 + n) % n ))
    local next=$(( (INDEX + 1) % n ))

    printf '\033[2J\033[H'
    clear_images

    icat --place "${side_w}x${img_h}@0x0"             "${IMAGES[$prev]}"
    icat --place "${center_w}x${img_h}@${center_x}x0" "${IMAGES[$INDEX]}"
    icat --place "${side_w}x${img_h}@${next_x}x0"     "${IMAGES[$next]}"

    tput cup $(( rows - 2 )) 0
    printf '  [%d/%d] %s\n' $(( INDEX + 1 )) "$n" "$(basename "${IMAGES[$INDEX]}")"
    local hints='  h/←: prev  l/→: next  Enter: set wallpaper  q: quit'
    (( VERBOSE )) && hints+="  [log: $LOG]"
    printf '%s' "$hints"
}

set_wallpaper() {
    local path="$1" prev="$CURRENT_WALLPAPER"
    local out rc

    vlog "=== set_wallpaper: $path ==="

    out=$(hyprctl hyprpaper preload "$path" 2>&1); rc=$?
    vlog "preload exit=$rc out=$out"
    # Don't bail on preload failure — image may already be preloaded

    local monitors_out ok=0
    monitors_out=$(hyprctl monitors 2>&1)
    vlog "monitors: $monitors_out"

    while IFS= read -r mon; do
        out=$(hyprctl hyprpaper wallpaper "$mon,$path" 2>&1); rc=$?
        vlog "wallpaper $mon exit=$rc out=$out"
        (( rc == 0 )) && ok=1
    done < <(printf '%s\n' "$monitors_out" | awk '/^Monitor /{print $2}')

    if (( ok == 0 )); then
        vlog "FAILED: no monitor set"
        return 1
    fi

    CURRENT_WALLPAPER="$path"
    if [[ -n "$prev" && "$prev" != "$path" ]]; then
        out=$(hyprctl hyprpaper unload "$prev" 2>&1); rc=$?
        vlog "unload prev exit=$rc out=$out"
    fi
    return 0
}

read_key() {
    local key
    IFS= read -rsn1 key
    if [[ $key == $'\x1b' ]]; then
        local rest
        IFS= read -rsn2 -t 0.1 rest
        key+="$rest"
    fi
    printf '%s' "$key"
}

old_stty=$(stty -g)
trap 'stty "$old_stty"; clear_images; tput cnorm; printf "\033[2J\033[H"' EXIT
stty -echo -icanon -icrnl min 1 time 0
tput civis

draw

while true; do
    key=$(read_key)
    case "$key" in
        h|$'\x1b[D')
            INDEX=$(( (INDEX - 1 + ${#IMAGES[@]}) % ${#IMAGES[@]} ))
            draw ;;
        l|$'\x1b[C')
            INDEX=$(( (INDEX + 1) % ${#IMAGES[@]} ))
            draw ;;
        $'\r'|$'\n')
            if set_wallpaper "${IMAGES[$INDEX]}"; then
                tput cup $(( $(tput lines) - 1 )) 0
                printf '  Wallpaper set: %s' "$(basename "${IMAGES[$INDEX]}")"
            else
                tput cup $(( $(tput lines) - 1 )) 0
                printf '  Failed — is hyprpaper running?'
                (( VERBOSE )) && printf ' [see %s]' "$LOG"
            fi ;;
        q|Q) break ;;
    esac
done