// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
//
// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file,
// You can obtain one at https://github.com/gogf/gf.

// Package gvalid implements powerful and useful data/form validation functionality.
package gvalid

import (
	"context"
	"reflect"
	"regexp"
	"strings"

	"github.com/gogf/gf/v2/internal/intlog"
	"github.com/gogf/gf/v2/text/gregex"
)

// CustomMsg is the custom error message type,
// like: map[field] => string|map[rule]string
type CustomMsg = map[string]interface{}

// fieldRule defined the alias name and rule string for specified field.
type fieldRule struct {
	Name      string       // Alias name for the field.
	Rule      string       // Rule string like: "max:6"
	IsMeta    bool         // Is this rule is from gmeta.Meta, which marks it as whole struct rule.
	FieldKind reflect.Kind // Kind of struct field, which is used for parameter type checks.
}

// iNoValidation is an interface that marks current struct not validated by package `gvalid`.
type iNoValidation interface {
	NoValidation()
}

const (
	singleRulePattern         = `^([\w-]+):{0,1}(.*)` // regular expression pattern for single validation rule.
	internalRulesErrRuleName  = "InvalidRules"        // rule name for internal invalid rules validation error.
	internalParamsErrRuleName = "InvalidParams"       // rule name for internal invalid params validation error.
	internalObjectErrRuleName = "InvalidObject"       // rule name for internal invalid object validation error.
	internalErrorMapKey       = "__InternalError__"   // error map key for internal errors.
	internalDefaultRuleName   = "__default__"         // default rule name for i18n error message format if no i18n message found for specified error rule.
	ruleMessagePrefixForI18n  = "gf.gvalid.rule."     // prefix string for each rule configuration in i18n content.
	noValidationTagName       = "nv"                  // no validation tag name for struct attribute.
	ruleNameRegex             = "regex"               // the name for rule "regex"
	ruleNameNotRegex          = "not-regex"           // the name for rule "not-regex"
	ruleNameForeach           = "foreach"             // the name for rule "foreach"
	ruleNameBail              = "bail"                // the name for rule "bail"
	ruleNameCi                = "ci"                  // the name for rule "ci"
	emptyJsonArrayStr         = "[]"                  // Empty json string for array type.
	emptyJsonObjectStr        = "{}"                  // Empty json string for object type.
	requiredRulesPrefix       = "required"            // requiredRulesPrefix specifies the rule prefix that must be validated even the value is empty (nil or empty).
)

var (
	// defaultErrorMessages is the default error messages.
	// Note that these messages are synchronized from ./i18n/en/validation.toml .
	defaultErrorMessages = map[string]string{
		internalDefaultRuleName: "The {field} value `{value}` is invalid",
	}

	structTagPriority    = []string{"gvalid", "valid", "v"} // structTagPriority specifies the validation tag priority array.
	aliasNameTagPriority = []string{"param", "params", "p"} // aliasNameTagPriority specifies the alias tag priority array.

	// all internal error keys.
	internalErrKeyMap = map[string]string{
		internalRulesErrRuleName:  internalRulesErrRuleName,
		internalParamsErrRuleName: internalParamsErrRuleName,
		internalObjectErrRuleName: internalObjectErrRuleName,
	}
	// regular expression object for single rule
	// which is compiled just once and of repeatable usage.
	ruleRegex, _ = regexp.Compile(singleRulePattern)

	// decorativeRuleMap defines all rules that are just marked rules which have neither functional meaning
	// nor error messages.
	decorativeRuleMap = map[string]bool{
		ruleNameForeach: true,
		ruleNameBail:    true,
		ruleNameCi:      true,
	}
)

// ParseTagValue parses one sequence tag to field, rule and error message.
// The sequence tag is like: [alias@]rule[...#msg...]
func ParseTagValue(tag string) (field, rule, msg string) {
	// Complete sequence tag.
	// Example: name@required|length:2,20|password3|same:password1#||密码强度不足|两次密码不一致
	match, _ := gregex.MatchString(`\s*((\w+)\s*@){0,1}\s*([^#]+)\s*(#\s*(.*)){0,1}\s*`, tag)
	if len(match) > 5 {
		msg = strings.TrimSpace(match[5])
		rule = strings.TrimSpace(match[3])
		field = strings.TrimSpace(match[2])
	} else {
		intlog.Errorf(context.TODO(), `invalid validation tag value: %s`, tag)
	}
	return
}

// GetTags returns the validation tags.
func GetTags() []string {
	return structTagPriority
}