{ config, lib, pkgs, flakeRoot, ... }:

let
  userRelRoot = "nixos_conf/wallpaperstuff";
  userAbsRoot = "${config.home.homeDirectory}/${userRelRoot}";
  picturesDir = "${userAbsRoot}/pictures";
  repoWallpaperDir = flakeRoot.outPath + "/assets/conf/desktop/wallpaper";
  repoWallpapersOnly = lib.cleanSourceWith {
    src = repoWallpaperDir;
    filter = path: type: true;
  };
  daemonRel = ".config/hypr/scripts/hyprpaper-ws-daemon.sh";
  setRel = ".config/hypr/scripts/set-wallpaper.sh";
in
{
  home.packages = [
    pkgs.hyprpaper
    pkgs.socat
    pkgs.jq
    pkgs.findutils
    pkgs.coreutils
    pkgs.gnused
    pkgs.gawk
  ];

  # Sync wallpapers into a writable directory
  home.file."${userRelRoot}" = {
    source = repoWallpapersOnly;
    recursive = true;
  };

  # Hyprpaper config
  home.file.".config/hypr/hyprpaper.conf" = {
    text = ''
      ipc = true
      splash = false
    '';
  };

  # Workspace wallpaper daemon
  home.file."${daemonRel}" = {
    executable = true;
    text = ''
      #!/usr/bin/env bash
      set -euo pipefail
      : "${XDG_RUNTIME_DIR?"XDG_RUNTIME_DIR not set"}"
      : "${HYPRLAND_INSTANCE_SIGNATURE?"HYPRLAND_INSTANCE_SIGNATURE not set"}"

      SOCK="${XDG_RUNTIME_DIR}/hypr/${HYPRLAND_INSTANCE_SIGNATURE}/.socket2.sock"
      [[ -S "$SOCK" ]] || { echo "Hyprland socket not found: $SOCK" >&2; exit 1; }

      PICTURES_DIR="${1:-${picturesDir}}"  # $1 = eerste argument, ${picturesDir} = default (Bash-variabele)
      FIT_MODE="fill"
      HYPR_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/hypr"  # Gebruik $HOME als fallback
      MAP_ROOT="${HYPR_DIR}/hyprpaper/config"

      focused_monitor() {
        hyprctl -j monitors | jq -r '.[] | select(.focused==true) | .name' | head -n 1
      }

      map_file_for_monitor() {
        local mon="$1"
        echo "${MAP_ROOT}/${mon}/defaults.conf"
      }

      ensure_map_file() {
        local mon="$1"
        local f
        f="$(map_file_for_monitor "$mon")"
        mkdir -p "$(dirname "$f")"
        if [[ ! -f "$f" ]]; then
          {
            for i in 1 2 3 4 5 6 7 8 9; do
              seed="$(ls -1 "${PICTURES_DIR}/${i}."* 2>/dev/null | head -n 1 || true)"
              echo "w-${i}=${seed}"
            done
          } > "$f"
        fi
        echo "$f"
      }

      get_wall_for_ws() {
        local mon="$1"
        local wsid="$2"
        local f key val
        f="$(ensure_map_file "$mon")"
        key="w-${wsid}"
        val="$(awk -F= -v k="$key" '$1==k {sub(/^[[:space:]]+/, "", $2); print $2; exit}' "$f" || true)"
        echo "$val"
      }

      apply_wallpaper() {
        local mon="$1"
        local wsid="$2"
        local file
        file="$(get_wall_for_ws "$mon" "$wsid")"
        [[ -n "$file" ]] || return 0
        [[ -f "$file" ]] || return 0
        hyprctl hyprpaper wallpaper "$mon, $file, $FIT_MODE" >/dev/null
      }

      mon="$(focused_monitor || true)"
      wsid="$(hyprctl -j activeworkspace | jq -r '.id' | head -n 1 || true)"
      [[ -n "$mon" && -n "$wsid" ]] && apply_wallpaper "$mon" "$wsid"

      handle() {
        local line="$1"
        case "$line" in
          workspacev2* )
            payload="${line#*>>}"
            wsid="${payload%%,*}"
            mon="$(focused_monitor || true)"
            [[ -n "$mon" && -n "$wsid" ]] && apply_wallpaper "$mon" "$wsid"
            ;;
          focusedmon* )
            mon="$(focused_monitor || true)"
            wsid="$(hyprctl -j activeworkspace | jq -r '.id' | head -n 1 || true)"
            [[ -n "$mon" && -n "$wsid" ]] && apply_wallpaper "$mon" "$wsid"
            ;;
        esac
      }

      socat -U - UNIX-CONNECT:"$SOCK" | while read -r line; do
        handle "$line" || true
      done
    '';
  };

  # CLI setter
  home.file."${setRel}" = {
    executable = true;
    text = ''
      #!/usr/bin/env bash
      set -euo pipefail

      HYPR_DIR="${XDG_CONFIG_HOME:-$HOME/.config}/hypr"
      MAP_ROOT="${HYPR_DIR}/hyprpaper/config"

      usage() {
        echo "Usage: $0 <workspace_id> <monitor> [wallpaper_path]"
      }

      wsid="${1:-}"
      mon="${2:-}"
      wp="${3:-}"

      [[ -n "$wsid" ]] || { usage; exit 1; }
      [[ -n "$mon"  ]] || { usage; exit 1; }

      cfg="${MAP_ROOT}/${mon}/defaults.conf"
      mkdir -p "$(dirname "$cfg")"
      [[ -f "$cfg" ]] || touch "$cfg"

      if [[ -z "$wp" ]]; then
        wp="$(find "${XDG_CONFIG_HOME:-$HOME/.config}/wallpapers/defaults" -type f 2>/dev/null | shuf -n 1 || true)"
        [[ -n "$wp" ]] || { echo "No wallpaper found (random). Provide a path as arg 3."; exit 1; }
      fi

      key="w-${wsid}"
      if ! grep -q "^${key}=" "$cfg"; then
        echo "${key}=" >> "$cfg"
      fi

      sed -i "s|^${key}=.*|${key}= ${wp}|g" "$cfg"

      curws="$(hyprctl -j monitors | jq -r --arg m "$mon" '.[] | select(.name==$m) | .activeWorkspace.id' | head -n 1 || true)"
      if [[ "$curws" == "$wsid" ]]; then
        hyprctl hyprpaper wallpaper "$mon, $wp, fill" >/dev/null
      fi
    '';
  };

  # Services
  systemd.user.services.hyprpaper = {
    Unit = {
      Description = "hyprpaper wallpaper daemon";
      PartOf = [ "graphical-session.target" ];
      After = [ "graphical-session.target" ];
    };
    Service = {
      ExecStart = "${pkgs.hyprpaper}/bin/hyprpaper";
      Restart = "on-failure";
      RestartSec = 1;
    };
    Install = { WantedBy = [ "graphical-session.target" ]; };
  };

  systemd.user.services.hyprpaper-ws-daemon = {
    Unit = {
      Description = "Workspace->wallpaper mapping daemon (hyprpaper + socket2)";
      PartOf = [ "graphical-session.target" ];
      After = [ "graphical-session.target" "hyprpaper.service" ];
    };
    Service = {
      ExecStart = "${pkgs.bash}/bin/bash ${config.home.homeDirectory}/${daemonRel} ${picturesDir}";
      Restart = "on-failure";
      RestartSec = 1;
    };
    Install = { WantedBy = [ "graphical-session.target" ]; };
  };
}