#!/bin/bash
set -euo pipefail

# =============================================================================
# 功能描述: 
#   从指定 API 获取随机壁纸，强制转换为 PNG 格式，并使用 dms IPC 协议设置为桌面壁纸。
# 
# 核心特性:
#   1. 异步下载与长耗时心跳通知。
#   2. 健壮性检查：校验文件大小与 MIME 类型，剔除损坏/无效文件。
#   3. 格式转换：自动将下载的图片(无论原格式)转换为 dms 支持的 PNG 格式。
#   4. 资源自清洁：根据配置自动清理历史壁纸，保持存储整洁。
#   5. 解耦设计：更新完毕后触发异步的系统 UI 更新钩子 (matugen, niri等)。
# 
# 选项:
#   -k: 保留模式，不清理旧壁纸
#   -s: 静默模式，关闭桌面通知
#   -h: 显示帮助信息
# 
# 依赖:
#   curl, file, notify-send, ImageMagick (magick 或 convert)
# =============================================================================

# ================= 默认配置 =================
API_URL="https://t.alcy.cc/pc/"
SAVE_DIR="$HOME/Pictures/Wallpapers/api-random-download"

# 自动清理时保留最近多少张图片
KEEP_COUNT=40

# 默认开关状态 (可被参数覆盖)
ENABLE_CLEANUP=true
SILENT_MODE=false

# ================= 参数解析 =================
usage() {
    echo "用法: $(basename "$0") [-k] [-s] [-h]"
    echo "  -k  (Keep)    保留模式：不清理旧壁纸"
    echo "  -s  (Silent)  静默模式：不发送任何 notify-send 通知"
    echo "  -h  帮助信息"
    exit 0
}

while getopts "ksh" opt; do
  case $opt in
    k) ENABLE_CLEANUP=false ;;
    s) SILENT_MODE=true ;;
    h) usage ;;
    *) usage ;;
  esac
done

# ================= 辅助函数 =================

# 统一通知函数 (兼容 set -u 处理未传递的 $3)
send_notify() {
    if [ "$SILENT_MODE" = false ]; then
        notify-send "$1" "$2" ${3:-}
    fi
}

# ================= 主逻辑 =================

mkdir -p "$SAVE_DIR"
TIMESTAMP=$(date +%s)
RAW_PATH="${SAVE_DIR}/wall_${TIMESTAMP}_raw.tmp"
FINAL_PATH="${SAVE_DIR}/wall_${TIMESTAMP}.png"

# --- 1. 下载模块 (带心跳通知) ---

if [ "$SILENT_MODE" = false ]; then
    (
        sleep 8
        while true; do
            notify-send "Wallpaper" "Downloading is still in progress..." --expire-time=5000 --icon=drive-harddisk --replace-id=999 || true
            sleep 8
        done
    ) &
    NOTIFY_PID=$!
else
    NOTIFY_PID=""
fi

send_notify "Wallpaper" "Downloading from Alcy..." "--expire-time=5000"

USER_AGENT="Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36"

# 执行下载并做严格模式下的安全判断
if ! curl -L -s -A "$USER_AGENT" --connect-timeout 10 -m 120 -o "$RAW_PATH" "$API_URL"; then
    [ -n "${NOTIFY_PID:-}" ] && kill "$NOTIFY_PID" 2>/dev/null || true
    send_notify "Wallpaper Error" "Download failed (Network/API Error)"
    exit 1
fi

# 下载结束，杀掉通知进程
if [ -n "${NOTIFY_PID:-}" ]; then
    kill "$NOTIFY_PID" 2>/dev/null || true
fi

# 校验文件 (大小)
if [ ! -f "$RAW_PATH" ] || [ "$(wc -c < "$RAW_PATH")" -lt 20480 ]; then
    send_notify "Wallpaper Error" "Download failed (File too small/Invalid)"
    rm -f "$RAW_PATH"
    exit 1
fi

# 校验文件 (MIME 类型)
FILE_TYPE=$(file --mime-type -b "$RAW_PATH" || echo "unknown")
if [[ "$FILE_TYPE" != image/* ]]; then
    send_notify "Wallpaper Error" "Not an image file ($FILE_TYPE)"
    rm -f "$RAW_PATH"
    exit 1
fi

# --- 2. 格式转换模块 (转为 PNG) ---

# 检查 ImageMagick 是否存在 (兼容新版 magick 和旧版 convert)
if command -v magick > /dev/null 2>&1; then
    IMG_TOOL="magick"
elif command -v convert > /dev/null 2>&1; then
    IMG_TOOL="convert"
else
    send_notify "Wallpaper Error" "ImageMagick not found. Please install it." 
    rm -f "$RAW_PATH"
    exit 1
fi

# 执行转换
if ! $IMG_TOOL "$RAW_PATH" "$FINAL_PATH"; then
    send_notify "Wallpaper Error" "Failed to convert image to PNG format" 
    rm -f "$RAW_PATH" "$FINAL_PATH"
    exit 1
fi

# 转换成功，清理原始临时文件
rm -f "$RAW_PATH"

# --- 3. 应用模块 (dms ipc call) ---

dms ipc call wallpaper set "$FINAL_PATH"

# --- 4. 钩子与清理 ---
(
    if [ -x "$HOME/.config/scripts/matugen-update.sh" ]; then
        "$HOME/.config/scripts/matugen-update.sh" "$FINAL_PATH" > /dev/null || true
    fi
    
    sleep 0.5
    
    if [ -x "$HOME/.config/scripts/niri_set_overview_blur_dark_bg.sh" ]; then
        "$HOME/.config/scripts/niri_set_overview_blur_dark_bg.sh" > /dev/null || true
    fi
    
    # 动态清理逻辑
    if [ "$ENABLE_CLEANUP" = true ]; then
        DELETE_START=$((KEEP_COUNT + 1))
        cd "$SAVE_DIR" && ls -t | tail -n +"$DELETE_START" | xargs -I {} rm -- {} 2>/dev/null || true
    fi
) &

send_notify "Wallpaper Updated" "PNG applied successfully!"