#!/usr/bin/env sh
# 文档链接有效性检查脚本

set -eu

echo "========================================"
echo "🔗 文档链接有效性检查"
echo "========================================"

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
PLAYBOOK_ROOT="$(cd "$SCRIPT_DIR/../.." && pwd)"

TOTAL_LINKS=0
VALID_LINKS=0
BROKEN_LINKS=0
SKIPPED_LINKS=0

BROKEN_LINKS_FILE="/tmp/broken_links.txt"
REPORT_FILE="/tmp/doc_links_report.txt"

> "$BROKEN_LINKS_FILE"
> "$REPORT_FILE"

echo "📁 Playbook 根目录: $PLAYBOOK_ROOT"
echo ""

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

check_file_link() {
    local source_file="$1"
    local link_path="$2"
    local link_line="$3"

    TOTAL_LINKS=$((TOTAL_LINKS + 1))

    # 处理相对路径
    local source_dir
    source_dir="$(dirname "$source_file")"

    # 解析链接路径
    local target_path="$link_path"

    # 移除锚点
    target_path="${target_path%%#*}"

    # 跳过空链接
    if [ -z "$target_path" ]; then
        SKIPPED_LINKS=$((SKIPPED_LINKS + 1))
        return 0
    fi

    # 跳过外部链接（http/https）
    if echo "$target_path" | grep -qE "^https?://"; then
        SKIPPED_LINKS=$((SKIPPED_LINKS + 1))
        return 0
    fi

    # 跳过 mailto 链接
    if echo "$target_path" | grep -q "^mailto:"; then
        SKIPPED_LINKS=$((SKIPPED_LINKS + 1))
        return 0
    fi

    # 构建绝对路径
    local absolute_path
    if echo "$target_path" | grep -q "^/"; then
        # 绝对路径（从仓库根）
        absolute_path="$PLAYBOOK_ROOT$target_path"
    else
        # 相对路径
        absolute_path="$source_dir/$target_path"
    fi

    # 规范化路径
    absolute_path="$(cd "$(dirname "$absolute_path")" 2>/dev/null && pwd)/$(basename "$absolute_path")" || absolute_path=""

    # 检查文件是否存在
    if [ -n "$absolute_path" ] && [ -e "$absolute_path" ]; then
        VALID_LINKS=$((VALID_LINKS + 1))
        return 0
    else
        BROKEN_LINKS=$((BROKEN_LINKS + 1))
        echo "❌ 断链: $source_file:$link_line" >> "$BROKEN_LINKS_FILE"
        echo "   链接: $link_path" >> "$BROKEN_LINKS_FILE"
        echo "   目标: $absolute_path" >> "$BROKEN_LINKS_FILE"
        echo "" >> "$BROKEN_LINKS_FILE"
        return 1
    fi
}

extract_links() {
    awk '
        BEGIN { in_code = 0 }
        {
            line = $0
            if (line ~ /^```/) { in_code = !in_code; next }
            if (in_code) next

            gsub(/`[^`]*`/, "", line)

            while (match(line, /\[[^]]+\]\([^)]*\)/)) {
                link = substr(line, RSTART, RLENGTH)
                sub(/^\[[^]]+\]\(/, "", link)
                sub(/\)$/, "", link)
                print NR "\t" link
                line = substr(line, RSTART + RLENGTH)
            }

            if (match(line, /^\[[^]]+\]:[[:space:]]*[^[:space:]]+/)) {
                link = substr(line, RSTART, RLENGTH)
                sub(/^\[[^]]+\]:[[:space:]]*/, "", link)
                sub(/[[:space:]].*$/, "", link)
                print NR "\t" link
            }
        }
    ' "$1"
}

# ============================================
# 查找并检查所有 Markdown 文件
# ============================================

echo "🔍 扫描 Markdown 文件..."

cd "$PLAYBOOK_ROOT"

MD_FILES=$(find . -name "*.md" \
    -not -name "*.template.md" \
    -not -path "*/node_modules/*" \
    -not -path "*/.git/*" \
    -not -path "*/build/*" \
    -not -path "*/dist/*" \
    2>/dev/null || true)

FILE_COUNT=$(echo "$MD_FILES" | grep -c "^" || echo 0)
echo "📄 找到 $FILE_COUNT 个 Markdown 文件"
echo ""

CURRENT_FILE_NUM=0

for md_file in $MD_FILES; do
    CURRENT_FILE_NUM=$((CURRENT_FILE_NUM + 1))

    # 显示进度
    if [ "$CURRENT_FILE_NUM" -eq 1 ] || [ $((CURRENT_FILE_NUM % 10)) -eq 0 ] || [ "$CURRENT_FILE_NUM" -eq "$FILE_COUNT" ]; then
        echo "📖 处理中... [$CURRENT_FILE_NUM/$FILE_COUNT] $md_file"
    fi

    links_file="$(mktemp)"
    extract_links "$md_file" > "$links_file"
    while IFS="$(printf '\t')" read -r line_num link; do
        check_file_link "$md_file" "$link" "$line_num" || true
    done < "$links_file"
    rm -f "$links_file"
done

echo ""
echo "✅ 扫描完成"
echo ""

# ============================================
# 生成检查报告
# ============================================

echo "========================================"
echo "📊 链接检查结果统计"
echo "========================================"
echo "🔗 总链接数: $TOTAL_LINKS"
echo "✅ 有效链接: $VALID_LINKS"
echo "⏭️  跳过链接: $SKIPPED_LINKS (外部/mailto)"
echo "❌ 断开链接: $BROKEN_LINKS"

if [ "$TOTAL_LINKS" -gt 0 ]; then
    CHECKED_LINKS=$((TOTAL_LINKS - SKIPPED_LINKS))
    if [ "$CHECKED_LINKS" -gt 0 ]; then
        SUCCESS_RATE=$(awk "BEGIN {printf \"%.1f\", ($VALID_LINKS * 100.0) / $CHECKED_LINKS}")
        echo "📈 有效率: $SUCCESS_RATE%"
    fi
fi

echo ""

# 写入报告
{
    echo "文档链接有效性检查报告"
    echo "========================"
    echo ""
    echo "检查时间: $(date '+%Y-%m-%d %H:%M:%S')"
    echo "检查目录: $PLAYBOOK_ROOT"
    echo ""
    echo "统计结果:"
    echo "  总链接数: $TOTAL_LINKS"
    echo "  有效链接: $VALID_LINKS"
    echo "  跳过链接: $SKIPPED_LINKS"
    echo "  断开链接: $BROKEN_LINKS"
    echo ""
    if [ "$BROKEN_LINKS" -gt 0 ]; then
        echo "断开链接详情:"
        echo "=============="
        cat "$BROKEN_LINKS_FILE"
    fi
} > "$REPORT_FILE"

if [ "$BROKEN_LINKS" -gt 0 ]; then
    echo "❌ 发现 $BROKEN_LINKS 个断开的链接"
    echo ""
    echo "断开链接详情:"
    cat "$BROKEN_LINKS_FILE"
    echo ""
    echo "📄 详细报告: $REPORT_FILE"
fi

echo "========================================"

# 清理临时文件（保留报告用于 CI）
# rm -f "$BROKEN_LINKS_FILE"

# 返回结果
if [ "$BROKEN_LINKS" -eq 0 ]; then
    echo "✅ 所有文档链接检查通过"
    exit 0
else
    echo "❌ 文档链接检查失败"
    exit 1
fi