package engine

import (
	"strings"

	"git.kingecg.top/kingecg/gomog/pkg/types"
)

// MatchFilter 匹配过滤器
func MatchFilter(doc map[string]interface{}, filter types.Filter) bool {
	if filter == nil || len(filter) == 0 {
		return true
	}

	for key, condition := range filter {
		switch key {
		case "$and":
			if !handleAnd(doc, condition) {
				return false
			}
		case "$or":
			if !handleOr(doc, condition) {
				return false
			}
		case "$nor":
			if !handleNor(doc, condition) {
				return false
			}
		case "$not":
			if !handleNot(doc, condition) {
				return false
			}
		default:
			if !matchField(doc, key, condition) {
				return false
			}
		}
	}

	return true
}

// handleAnd 处理 $and 操作符
func handleAnd(doc map[string]interface{}, condition interface{}) bool {
	andConditions, ok := condition.([]interface{})
	if !ok {
		return false
	}

	for _, cond := range andConditions {
		if condMap, ok := cond.(map[string]interface{}); ok {
			if !MatchFilter(doc, condMap) {
				return false
			}
		}
	}
	return true
}

// handleOr 处理 $or 操作符
func handleOr(doc map[string]interface{}, condition interface{}) bool {
	orConditions, ok := condition.([]interface{})
	if !ok {
		return false
	}

	for _, cond := range orConditions {
		if condMap, ok := cond.(map[string]interface{}); ok {
			if MatchFilter(doc, condMap) {
				return true
			}
		}
	}
	return false
}

// handleNor 处理 $nor 操作符
func handleNor(doc map[string]interface{}, condition interface{}) bool {
	orConditions, ok := condition.([]interface{})
	if !ok {
		return false
	}

	for _, cond := range orConditions {
		if condMap, ok := cond.(map[string]interface{}); ok {
			if MatchFilter(doc, condMap) {
				return false
			}
		}
	}
	return true
}

// handleNot 处理 $not 操作符
func handleNot(doc map[string]interface{}, condition interface{}) bool {
	if condMap, ok := condition.(map[string]interface{}); ok {
		return !MatchFilter(doc, condMap)
	}
	return true
}

// matchField 匹配字段
func matchField(doc map[string]interface{}, key string, condition interface{}) bool {
	value := getNestedValue(doc, key)

	// 处理操作符条件
	if condMap, ok := condition.(map[string]interface{}); ok {
		return evaluateOperators(value, condMap)
	}

	// 简单相等比较
	return compareEq(value, condition)
}

// getNestedValue 获取嵌套字段值（支持 "a.b.c" 格式）
func getNestedValue(doc map[string]interface{}, key string) interface{} {
	parts := strings.Split(key, ".")
	var current interface{} = doc

	for _, part := range parts {
		if m, ok := current.(map[string]interface{}); ok {
			current = m[part]
		} else {
			return nil
		}
	}

	return current
}

// evaluateOperators 评估操作符
func evaluateOperators(value interface{}, operators map[string]interface{}) bool {
	for op, operand := range operators {
		switch op {
		case "$eq":
			if !compareEq(value, operand) {
				return false
			}
		case "$ne":
			if compareEq(value, operand) {
				return false
			}
		case "$gt":
			if !compareGt(value, operand) {
				return false
			}
		case "$gte":
			if !compareGte(value, operand) {
				return false
			}
		case "$lt":
			if !compareLt(value, operand) {
				return false
			}
		case "$lte":
			if !compareLte(value, operand) {
				return false
			}
		case "$in":
			if !compareIn(value, operand) {
				return false
			}
		case "$nin":
			if compareIn(value, operand) {
				return false
			}
		case "$regex":
			if !compareRegex(value, operand) {
				return false
			}
		case "$exists":
			exists := value != nil
			if operandBool, ok := operand.(bool); ok {
				if exists != operandBool {
					return false
				}
			}
		case "$type":
			if !compareType(value, operand) {
				return false
			}
		case "$all":
			if !compareAll(value, operand) {
				return false
			}
		case "$elemMatch":
			if !compareElemMatch(value, operand) {
				return false
			}
		case "$size":
			if !compareSize(value, operand) {
				return false
			}
		default:
			// 未知操作符，跳过
		}
	}
	return true
}