#!/bin/bash

# Zed Remote Server Auto-Downloader
# 支持自动检测最新版本或指定版本下载

set -e

ZED_SERVER_DIR="$HOME/.zed_server"
GITHUB_REPO="zed-industries/zed"
ARCH="x86_64"

# 颜色输出
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

# 显示帮助信息
show_help() {
    cat << EOF
Zed Remote Server 下载工具

用法: $0 [选项]

选项:
    -v, --version VERSION    指定版本号下载 (例如: 0.230.0)
    -l, --list              列出已安装的版本
    -h, --help              显示此帮助信息

示例:
    $0                      # 自动下载最新版本
    $0 -v 0.230.0           # 下载指定版本 0.230.0
EOF
}

# 列出已安装的版本
list_installed() {
    echo "📂 已安装的 Zed Server 版本："
    if [ -d "$ZED_SERVER_DIR" ]; then
        ls -1 "$ZED_SERVER_DIR" 2>/dev/null | grep "^zed-remote-server" | while read -r file; do
            if [ -f "$ZED_SERVER_DIR/$file" ]; then
                size=$(du -h "$ZED_SERVER_DIR/$file" 2>/dev/null | cut -f1)
                echo "  • $file (${size})"
            fi
        done
        echo ""
        LATEST_LINK="$ZED_SERVER_DIR/zed-remote-server-latest"
        if [ -L "$LATEST_LINK" ]; then
            echo "🔗 当前链接: $(readlink "$LATEST_LINK")"
        fi
    else
        echo "  无"
    fi
}

# 获取 tag 对应的 commit hash（通过 GitHub Git Refs API）
get_tag_commit() {
    local version="$1"
    local tag_ref="refs/tags/v${version}"

    local api_url="https://api.github.com/repos/${GITHUB_REPO}/git/${tag_ref}"
    local tag_info
    tag_info=$(curl -s "$api_url")

    local object_type
    object_type=$(echo "$tag_info" | grep -o '"type": "[^"]*' | head -1 | cut -d'"' -f4)

    local commit_sha
    if [ "$object_type" = "tag" ]; then
        # annotated tag：object.sha 才是真正的 commit hash
        commit_sha=$(echo "$tag_info" | grep -o '"object": {[^}]*' | grep -o '"sha": "[^"]*' | head -1 | cut -d'"' -f4)
    else
        # lightweight tag：顶层 sha 直接就是 commit hash
        commit_sha=$(echo "$tag_info" | grep -o '"sha": "[^"]*' | head -1 | cut -d'"' -f4)
    fi

    echo "$commit_sha"
}

# 对应 GitHub Actions 页面 https://github.com/zed-industries/zed/actions/workflows/release.yml 中显示的 #xxx
get_build_number() {
    local commit_sha="$1"

    if [ -z "$commit_sha" ]; then
        echo "0"
        return
    fi

    # 使用 /actions/workflows/release.yml/runs 端点，而非全局 /actions/runs
    # 这样拿到的 run_number 与页面显示的编号完全一致
    local runs_api="https://api.github.com/repos/${GITHUB_REPO}/actions/workflows/release.yml/runs?head_sha=${commit_sha}&per_page=5&status=completed"
    local runs_info
    runs_info=$(curl -s "$runs_api")

    local build_num
    build_num=$(echo "$runs_info" | grep -o '"run_number": [0-9]*' | head -1 | grep -o '[0-9]*')

    if [ -z "$build_num" ]; then
        build_num="0"
    fi

    echo "$build_num"
}

# 解析命令行参数
SPECIFIED_VERSION=""
while [[ $# -gt 0 ]]; do
    case $1 in
        -v|--version)
            SPECIFIED_VERSION="$2"
            shift 2
            ;;
        -l|--list)
            list_installed
            exit 0
            ;;
        -h|--help)
            show_help
            exit 0
            ;;
        *)
            echo -e "${RED}❌ 未知参数: $1${NC}"
            show_help
            exit 1
            ;;
    esac
done

# 获取 release 信息
if [ -n "$SPECIFIED_VERSION" ]; then
    echo "🔍 正在获取指定版本 v$SPECIFIED_VERSION..."
    SPECIFIED_VERSION=$(echo "$SPECIFIED_VERSION" | sed 's/^v//')
    GITHUB_API="https://api.github.com/repos/$GITHUB_REPO/releases/tags/v$SPECIFIED_VERSION"
else
    echo "🔍 正在检查最新版本..."
    GITHUB_API="https://api.github.com/repos/$GITHUB_REPO/releases/latest"
fi

RELEASE_INFO=$(curl -s "$GITHUB_API")

# 检查是否找到 release
if echo "$RELEASE_INFO" | grep -q '"message": "Not Found"'; then
    echo -e "${RED}❌ 未找到版本: v${SPECIFIED_VERSION}${NC}"
    exit 1
fi

# 解析版本号
VERSION=$(echo "$RELEASE_INFO" | grep -o '"tag_name": "[^"]*' | cut -d'"' -f4 | sed 's/^v//')

if [ -z "$VERSION" ]; then
    echo -e "${RED}❌ 无法获取版本信息${NC}"
    exit 1
fi

echo -e "${BLUE}📦 目标版本: v$VERSION${NC}"

# 通过 Git Refs API 获取准确的 commit hash
echo "🔍 正在获取准确的 commit hash..."
COMMIT_SHA=$(get_tag_commit "$VERSION")

if [ -z "$COMMIT_SHA" ]; then
    echo -e "${YELLOW}⚠️  无法通过 Git API 获取 commit，尝试使用 release 中的信息...${NC}"
    COMMIT_SHA=$(echo "$RELEASE_INFO" | grep -o '"target_commitish": "[^"]*' | cut -d'"' -f4)

    if [ "$COMMIT_SHA" = "main" ] || [ "$COMMIT_SHA" = "master" ]; then
        echo -e "${RED}❌ 无法获取准确的 commit hash${NC}"
        exit 1
    fi
fi

echo -e "${BLUE}🔖 Commit: ${COMMIT_SHA:0:12}...${NC}"

echo "🔍 正在获取构建号..."
BUILD_NUM=$(get_build_number "$COMMIT_SHA")

if [ "$BUILD_NUM" = "0" ]; then
    echo -e "${YELLOW}⚠️  无法获取构建号，使用默认值 0${NC}"
else
    echo -e "${BLUE}🔢 构建号: $BUILD_NUM${NC}"
fi

# 构建目标文件名
TARGET_NAME="zed-remote-server-stable-${VERSION}+stable.${BUILD_NUM}.${COMMIT_SHA}"
TARGET_PATH="$ZED_SERVER_DIR/$TARGET_NAME"

# 检查目标版本是否已存在
if [ -f "$TARGET_PATH" ]; then
    echo ""
    echo -e "${GREEN}✅ 版本已存在，跳过下载${NC}"
    echo "📍 位置: $TARGET_PATH"
    exit 0
fi

echo ""
echo -e "${YELLOW}⬇️  准备下载...${NC}"

# 获取 assets 列表
ASSETS_URL=$(echo "$RELEASE_INFO" | grep -o '"assets_url": "[^"]*' | cut -d'"' -f4)
ASSETS=$(curl -s "$ASSETS_URL")

# 查找对应架构的远程服务器包
FILENAME_PATTERN="zed-remote-server-linux-${ARCH}"
DOWNLOAD_URL=$(echo "$ASSETS" | grep -o '"browser_download_url": "[^"]*' | grep "$FILENAME_PATTERN" | head -1 | cut -d'"' -f4)

if [ -z "$DOWNLOAD_URL" ]; then
    echo -e "${RED}❌ 未找到适合 ${ARCH} 架构的远程服务器包${NC}"
    exit 1
fi

FILENAME=$(basename "$DOWNLOAD_URL")
echo "📥 下载文件: $FILENAME"

# 创建目录
mkdir -p "$ZED_SERVER_DIR"

# 下载文件
TEMP_DIR=$(mktemp -d)
TEMP_FILE="$TEMP_DIR/$FILENAME"

echo "⬇️  正在下载..."
curl -L --progress-bar -o "$TEMP_FILE" "$DOWNLOAD_URL"

if [ ! -f "$TEMP_FILE" ]; then
    echo -e "${RED}❌ 下载失败${NC}"
    rm -rf "$TEMP_DIR"
    exit 1
fi

# 解压
echo "📂 正在解压..."
gunzip -f "$TEMP_FILE"

EXTRACTED_FILE="${TEMP_FILE%.gz}"

# 移动到目标路径
if [ -f "$TARGET_PATH" ]; then
    echo -e "${YELLOW}⚠️  检测到目标文件已存在，跳过移动${NC}"
    rm -f "$EXTRACTED_FILE"
else
    mv "$EXTRACTED_FILE" "$TARGET_PATH"
    chmod +x "$TARGET_PATH"
    echo -e "${GREEN}✅ 安装完成！${NC}"
fi

# 清理临时文件
rm -rf "$TEMP_DIR"

echo "📍 位置: $TARGET_PATH"

# 验证安装
echo "🔍 验证..."
if "$TARGET_PATH" version 2>/dev/null; then
    :
else
    echo "（该版本可能不支持 --version 参数，但文件已就绪）"
fi

echo ""
echo -e "${GREEN}💡 使用提示:${NC}"
echo "   完整路径: $TARGET_PATH"