// Package distribution 收口代理分销注册、提现资格与提现审批的领域不变量。
// 本包不依赖 Fiber、GORM、Redis、Asynq 或具体第三方 SDK。
package distribution

import (
	"crypto/rand"
	"encoding/hex"
	"strconv"
	"strings"

	"github.com/break/junhong_cmp_fiber/pkg/constants"
	"github.com/break/junhong_cmp_fiber/pkg/errors"
)

const (
	distributionCodeBytes = 16
	phoneMaskedKeepPrefix = 3
	phoneMaskedKeepSuffix = 4
	codeMaskedKeepPrefix  = 4
	codeMaskedKeepSuffix  = 4
)

// GenerateDistributionCode 生成 32 位十六进制随机分销码。
// 唯一性由数据库条件唯一索引兜底，调用方在冲突时重新生成。
func GenerateDistributionCode() (string, error) {
	buf := make([]byte, distributionCodeBytes)
	if _, err := rand.Read(buf); err != nil {
		return "", errors.Wrap(errors.CodeInternalError, err, "生成分销码失败")
	}
	return hex.EncodeToString(buf), nil
}

// ValidateRegistrationInput 规范化并校验扫码注册输入。
// 手机号、用户名、店铺编号与店铺名称由公开接口必填；密码长度沿用账号体系既有下限。
func ValidateRegistrationInput(input RegistrationInput) (RegistrationInput, error) {
	input.DistributionCode = strings.TrimSpace(input.DistributionCode)
	input.Phone = strings.TrimSpace(input.Phone)
	input.Username = strings.TrimSpace(input.Username)
	input.ShopName = strings.TrimSpace(input.ShopName)
	input.ShopCode = strings.TrimSpace(input.ShopCode)
	input.ContactName = strings.TrimSpace(input.ContactName)
	input.Province = strings.TrimSpace(input.Province)
	input.City = strings.TrimSpace(input.City)
	input.District = strings.TrimSpace(input.District)
	input.Address = strings.TrimSpace(input.Address)
	if input.DistributionCode == "" || input.Phone == "" || input.Username == "" ||
		input.ShopName == "" || input.ShopCode == "" {
		return RegistrationInput{}, errors.New(errors.CodeInvalidParam, "分销码不可用")
	}
	if len(input.Phone) != 11 {
		return RegistrationInput{}, errors.New(errors.CodeInvalidParam, "手机号格式不正确")
	}
	if len(input.Username) < 3 || len(input.Username) > 50 {
		return RegistrationInput{}, errors.New(errors.CodeInvalidParam, "用户名长度必须为 3 至 50 个字符")
	}
	if len(input.Password) < 6 || len(input.Password) > 64 {
		return RegistrationInput{}, errors.New(errors.CodeInvalidParam, "密码长度必须为 6 至 64 个字符")
	}
	return input, nil
}

// ValidateQualificationInput 规范化并校验提现资料资格输入。
// 企业主体必须填写统一社会信用代码，个人主体必须填写法人身份证号；
// 发票仅企业可选，且抬头与统一社会信用代码必须与签约主体一致。
func ValidateQualificationInput(input QualificationInput) (QualificationInput, error) {
	input.SubjectCode = strings.TrimSpace(input.SubjectCode)
	input.LegalPersonIDCard = strings.TrimSpace(input.LegalPersonIDCard)
	input.ContractFileKey = strings.TrimSpace(input.ContractFileKey)
	input.IDCardFrontFileKey = strings.TrimSpace(input.IDCardFrontFileKey)
	input.IDCardBackFileKey = strings.TrimSpace(input.IDCardBackFileKey)
	input.BusinessLicenseFileKey = strings.TrimSpace(input.BusinessLicenseFileKey)
	input.ShopFrontFileKey = strings.TrimSpace(input.ShopFrontFileKey)
	input.InvoiceFileKey = strings.TrimSpace(input.InvoiceFileKey)
	input.InvoiceTitle = strings.TrimSpace(input.InvoiceTitle)
	input.InvoiceSubjectCode = strings.TrimSpace(input.InvoiceSubjectCode)

	switch input.SubjectType {
	case constants.WithdrawalQualificationSubjectTypeEnterprise:
		if input.SubjectCode == "" || input.LegalPersonIDCard == "" {
			return QualificationInput{}, errors.New(errors.CodeInvalidParam, "企业主体必须填写统一社会信用代码与法人身份证号")
		}
	case constants.WithdrawalQualificationSubjectTypePersonal:
		if input.LegalPersonIDCard == "" {
			return QualificationInput{}, errors.New(errors.CodeInvalidParam, "个人主体必须填写法人身份证号")
		}
		if input.SubjectCode == "" {
			// 个人主体的签约主体代码即法人身份证号。
			input.SubjectCode = input.LegalPersonIDCard
		}
	default:
		return QualificationInput{}, errors.New(errors.CodeInvalidParam, "签约主体类型无效")
	}
	if input.SubjectCode != input.LegalPersonIDCard && input.SubjectType == constants.WithdrawalQualificationSubjectTypePersonal {
		return QualificationInput{}, errors.New(errors.CodeInvalidParam, "个人主体的签约主体代码必须与法人身份证号一致")
	}
	if input.ContractFileKey == "" || input.IDCardFrontFileKey == "" || input.IDCardBackFileKey == "" {
		return QualificationInput{}, errors.New(errors.CodeInvalidParam, "合同与法人身份证正反面附件必须填写")
	}
	if input.SubjectType == constants.WithdrawalQualificationSubjectTypePersonal &&
		(input.InvoiceFileKey != "" || input.InvoiceTitle != "" || input.InvoiceSubjectCode != "") {
		return QualificationInput{}, errors.New(errors.CodeInvalidParam, "发票资料仅企业主体可提交")
	}
	if input.InvoiceFileKey != "" {
		if input.InvoiceTitle == "" || input.InvoiceSubjectCode == "" {
			return QualificationInput{}, errors.New(errors.CodeInvalidParam, "提交发票时必须填写抬头与统一社会信用代码")
		}
		if input.InvoiceSubjectCode != input.SubjectCode {
			return QualificationInput{}, errors.New(errors.CodeInvalidParam, "发票统一社会信用代码必须与合同主体一致")
		}
	}
	// 附件上限由结构保证：资格只有合同、法人身份证正反面、营业执照、门头照、发票共 6 个
	// 单对象键字段，天然不超过企业微信单张审批单 6 个附件上限，无需运行时计数校验。
	return input, nil
}

// MaskPhone 生成脱敏手机号，仅保留前 3 位与后 4 位。
// 日志与审计不得记录完整手机号。
func MaskPhone(phone string) string {
	phone = strings.TrimSpace(phone)
	if len(phone) < phoneMaskedKeepPrefix+phoneMaskedKeepSuffix {
		return ""
	}
	return phone[:phoneMaskedKeepPrefix] + "****" + phone[len(phone)-phoneMaskedKeepSuffix:]
}

// MaskSubjectCode 生成脱敏证件号或统一社会信用代码，仅保留前 4 位与后 4 位。
// 日志与审计不得记录完整证件号。
func MaskSubjectCode(code string) string {
	code = strings.TrimSpace(code)
	if len(code) < codeMaskedKeepPrefix+codeMaskedKeepSuffix {
		return ""
	}
	return code[:codeMaskedKeepPrefix] + "**********" + code[len(code)-codeMaskedKeepSuffix:]
}

// MaskDistributionCode 生成脱敏分销码，仅保留首尾片段。
// 分销码是可枚举的公开入口标识，日志与审计只记录脱敏值。
func MaskDistributionCode(code string) string {
	code = strings.TrimSpace(code)
	if len(code) < codeMaskedKeepPrefix+codeMaskedKeepSuffix {
		return ""
	}
	return code[:codeMaskedKeepPrefix] + "****" + code[len(code)-codeMaskedKeepSuffix:]
}

// FormatCentYuan 将分金额格式化为两位小数的元字符串，仅用于审批表单与展示。
func FormatCentYuan(amount int64) string {
	return strconv.FormatInt(amount/100, 10) + "." +
		pad2(strconv.FormatInt(amount%100, 10))
}

// pad2 将 0 至 99 的十进制文本左补零到两位。
func pad2(value string) string {
	if len(value) >= 2 {
		return value
	}
	return "0" + value
}

// RegistrationInput 是公开扫码注册的规范化输入。
type RegistrationInput struct {
	DistributionCode string
	Phone            string
	Username         string
	Password         string
	ShopName         string
	ShopCode         string
	ContactName      string
	Province         string
	City             string
	District         string
	Address          string
}

// QualificationInput 是提现资料资格的规范化输入。
type QualificationInput struct {
	SubjectType            string
	SubjectCode            string
	LegalPersonIDCard      string
	ContractFileKey        string
	IDCardFrontFileKey     string
	IDCardBackFileKey      string
	BusinessLicenseFileKey string
	ShopFrontFileKey       string
	InvoiceFileKey         string
	InvoiceTitle           string
	InvoiceSubjectCode     string
}