package validator

import (
	"fmt"
	"time"

	"google.golang.org/protobuf/reflect/protoreflect"
	"google.golang.org/protobuf/types/known/durationpb"
	"google.golang.org/protobuf/types/known/timestamppb"

	validate "git.ikuban.com/server/kubanapis/kuban/api/validate"
)

// validateEnum 验证枚举
func (e *Engine) validateEnum(
	vctx *ValidationContext,
	fieldRules *validate.FieldRules,
	rules *validate.EnumRules,
	value protoreflect.EnumNumber,
	field protoreflect.FieldDescriptor,
	fieldPath string,
	errors *ValidationErrors,
) error {
	intValue := int32(value)

	if rules.Const != nil && intValue != *rules.Const {
		defaultMsg := fmt.Sprintf("字段 %s 必须等于 %d", fieldPath, *rules.Const)
		errors.Add(NewValidationError(fieldPath, ErrCodeInvalidValue,
			e.getErrorMessage(fieldRules, vctx, "const", defaultMsg)))
	}

	// 验证是否为已定义的枚举值
	if rules.DefinedOnly != nil && *rules.DefinedOnly {
		enumValues := field.Enum().Values()
		found := false
		for i := 0; i < enumValues.Len(); i++ {
			if enumValues.Get(i).Number() == value {
				found = true
				break
			}
		}
		if !found {
			defaultMsg := fmt.Sprintf("字段 %s 的枚举值未定义", fieldPath)
			errors.Add(NewValidationError(fieldPath, ErrCodeInvalidValue,
				e.getErrorMessage(fieldRules, vctx, "defined_only", defaultMsg)))
		}
	}

	// in 验证
	if len(rules.In) > 0 {
		found := false
		for _, v := range rules.In {
			if intValue == v {
				found = true
				break
			}
		}
		if !found {
			defaultMsg := fmt.Sprintf("字段 %s 的值不在允许的列表中", fieldPath)
			errors.Add(NewValidationError(fieldPath, ErrCodeInvalidValue,
				e.getErrorMessage(fieldRules, vctx, "in", defaultMsg)))
		}
	}

	// not_in 验证
	if len(rules.NotIn) > 0 {
		for _, v := range rules.NotIn {
			if intValue == v {
				defaultMsg := fmt.Sprintf("字段 %s 的值在禁止列表中", fieldPath)
				errors.Add(NewValidationError(fieldPath, ErrCodeInvalidValue,
					e.getErrorMessage(fieldRules, vctx, "not_in", defaultMsg)))
				break
			}
		}
	}

	return nil
}

// validateBytes 验证字节数组
func (e *Engine) validateBytes(
	vctx *ValidationContext,
	fieldRules *validate.FieldRules,
	rules *validate.BytesRules,
	value []byte,
	fieldPath string,
	errors *ValidationErrors,
) error {
	// const 验证
	if rules.Const != nil && string(value) != string(rules.Const) {
		errors.Add(NewValidationError(fieldPath, ErrCodeInvalidValue,
			fmt.Sprintf("字段 %s 必须等于指定值", fieldPath)))
	}

	// 长度验证
	length := uint64(len(value))
	if rules.Len != nil && length != *rules.Len {
		errors.Add(NewValidationError(fieldPath, ErrCodeInvalidLength,
			fmt.Sprintf("字段 %s 长度必须为 %d 字节", fieldPath, *rules.Len)))
	}
	if rules.MinLen != nil && length < *rules.MinLen {
		errors.Add(NewValidationError(fieldPath, ErrCodeInvalidLength,
			fmt.Sprintf("字段 %s 长度至少为 %d 字节", fieldPath, *rules.MinLen)))
	}
	if rules.MaxLen != nil && length > *rules.MaxLen {
		errors.Add(NewValidationError(fieldPath, ErrCodeInvalidLength,
			fmt.Sprintf("字段 %s 长度最多为 %d 字节", fieldPath, *rules.MaxLen)))
	}

	// TODO: pattern, prefix, suffix, contains 验证

	// in 验证
	if len(rules.In) > 0 {
		found := false
		for _, allowed := range rules.In {
			if string(value) == string(allowed) {
				found = true
				break
			}
		}
		if !found {
			errors.Add(NewValidationError(fieldPath, ErrCodeInvalidValue,
				fmt.Sprintf("字段 %s 的值不在允许的列表中", fieldPath)))
		}
	}

	// not_in 验证
	if len(rules.NotIn) > 0 {
		for _, disallowed := range rules.NotIn {
			if string(value) == string(disallowed) {
				errors.Add(NewValidationError(fieldPath, ErrCodeInvalidValue,
					fmt.Sprintf("字段 %s 的值在禁止列表中", fieldPath)))
				break
			}
		}
	}

	return nil
}

// validateDuration 验证 Duration
func (e *Engine) validateDuration(
	vctx *ValidationContext,
	rules *validate.DurationRules,
	value *durationpb.Duration,
	fieldPath string,
	errors *ValidationErrors,
) error {
	if value == nil {
		if rules.Required != nil && *rules.Required {
			errors.Add(NewValidationError(fieldPath, ErrCodeRequired,
				fmt.Sprintf("字段 %s 是必填的", fieldPath)))
		}
		return nil
	}

	seconds := value.Seconds

	// const 验证
	if rules.ConstSeconds != nil && seconds != *rules.ConstSeconds {
		errors.Add(NewValidationError(fieldPath, ErrCodeInvalidValue,
			fmt.Sprintf("字段 %s 必须等于 %d 秒", fieldPath, *rules.ConstSeconds)))
	}

	// 范围验证
	if rules.LtSeconds != nil && seconds >= *rules.LtSeconds {
		errors.Add(NewValidationError(fieldPath, ErrCodeOutOfRange,
			fmt.Sprintf("字段 %s 必须小于 %d 秒", fieldPath, *rules.LtSeconds)))
	}
	if rules.LteSeconds != nil && seconds > *rules.LteSeconds {
		errors.Add(NewValidationError(fieldPath, ErrCodeOutOfRange,
			fmt.Sprintf("字段 %s 必须小于等于 %d 秒", fieldPath, *rules.LteSeconds)))
	}
	if rules.GtSeconds != nil && seconds <= *rules.GtSeconds {
		errors.Add(NewValidationError(fieldPath, ErrCodeOutOfRange,
			fmt.Sprintf("字段 %s 必须大于 %d 秒", fieldPath, *rules.GtSeconds)))
	}
	if rules.GteSeconds != nil && seconds < *rules.GteSeconds {
		errors.Add(NewValidationError(fieldPath, ErrCodeOutOfRange,
			fmt.Sprintf("字段 %s 必须大于等于 %d 秒", fieldPath, *rules.GteSeconds)))
	}

	return nil
}

// validateTimestamp 验证 Timestamp
func (e *Engine) validateTimestamp(
	vctx *ValidationContext,
	rules *validate.TimestampRules,
	value *timestamppb.Timestamp,
	fieldPath string,
	errors *ValidationErrors,
) error {
	if value == nil {
		if rules.Required != nil && *rules.Required {
			errors.Add(NewValidationError(fieldPath, ErrCodeRequired,
				fmt.Sprintf("字段 %s 是必填的", fieldPath)))
		}
		return nil
	}

	timestamp := value.Seconds

	// const 验证
	if rules.Const != nil && timestamp != *rules.Const {
		errors.Add(NewValidationError(fieldPath, ErrCodeInvalidValue,
			fmt.Sprintf("字段 %s 必须等于指定时间", fieldPath)))
	}

	// 范围验证
	if rules.Lt != nil && timestamp >= *rules.Lt {
		errors.Add(NewValidationError(fieldPath, ErrCodeOutOfRange,
			fmt.Sprintf("字段 %s 必须早于指定时间", fieldPath)))
	}
	if rules.Lte != nil && timestamp > *rules.Lte {
		errors.Add(NewValidationError(fieldPath, ErrCodeOutOfRange,
			fmt.Sprintf("字段 %s 必须早于或等于指定时间", fieldPath)))
	}
	if rules.Gt != nil && timestamp <= *rules.Gt {
		errors.Add(NewValidationError(fieldPath, ErrCodeOutOfRange,
			fmt.Sprintf("字段 %s 必须晚于指定时间", fieldPath)))
	}
	if rules.Gte != nil && timestamp < *rules.Gte {
		errors.Add(NewValidationError(fieldPath, ErrCodeOutOfRange,
			fmt.Sprintf("字段 %s 必须晚于或等于指定时间", fieldPath)))
	}

	// 相对时间验证
	now := time.Now().Unix()
	if rules.LtNow != nil && *rules.LtNow && timestamp >= now {
		errors.Add(NewValidationError(fieldPath, ErrCodeOutOfRange,
			fmt.Sprintf("字段 %s 必须在当前时间之前", fieldPath)))
	}
	if rules.GtNow != nil && *rules.GtNow && timestamp <= now {
		errors.Add(NewValidationError(fieldPath, ErrCodeOutOfRange,
			fmt.Sprintf("字段 %s 必须在当前时间之后", fieldPath)))
	}

	// 时间范围验证
	if rules.WithinSeconds != nil {
		diff := timestamp - now
		if diff < 0 {
			diff = -diff
		}
		if diff > *rules.WithinSeconds {
			errors.Add(NewValidationError(fieldPath, ErrCodeOutOfRange,
				fmt.Sprintf("字段 %s 必须在当前时间的 %d 秒内", fieldPath, *rules.WithinSeconds)))
		}
	}

	return nil
}