package models

import (
	"fmt"
	"strings"
	"time"

	"github.com/mayswind/ezbookkeeping/pkg/errs"
	"github.com/mayswind/ezbookkeeping/pkg/utils"
)

// TransactionType represents transaction type
type TransactionType byte

// Transaction types
const (
	TRANSACTION_TYPE_MODIFY_BALANCE TransactionType = 1
	TRANSACTION_TYPE_INCOME         TransactionType = 2
	TRANSACTION_TYPE_EXPENSE        TransactionType = 3
	TRANSACTION_TYPE_TRANSFER       TransactionType = 4
)

// TransactionDbType represents transaction type in database
type TransactionDbType byte

// Transaction db types
const (
	TRANSACTION_DB_TYPE_MODIFY_BALANCE TransactionDbType = 1
	TRANSACTION_DB_TYPE_INCOME         TransactionDbType = 2
	TRANSACTION_DB_TYPE_EXPENSE        TransactionDbType = 3
	TRANSACTION_DB_TYPE_TRANSFER_OUT   TransactionDbType = 4
	TRANSACTION_DB_TYPE_TRANSFER_IN    TransactionDbType = 5
)

// Transaction represents transaction data stored in database
type Transaction struct {
	TransactionId        int64             `xorm:"PK"`
	Uid                  int64             `xorm:"UNIQUE(UQE_transaction_uid_time) INDEX(IDX_transaction_uid_deleted_time) INDEX(IDX_transaction_uid_deleted_type_time) INDEX(IDX_transaction_uid_deleted_category_id_time) INDEX(IDX_transaction_uid_deleted_account_id_time) NOT NULL"`
	Deleted              bool              `xorm:"INDEX(IDX_transaction_uid_deleted_time) INDEX(IDX_transaction_uid_deleted_type_time) INDEX(IDX_transaction_uid_deleted_category_id_time) INDEX(IDX_transaction_uid_deleted_account_id_time) NOT NULL"`
	Type                 TransactionDbType `xorm:"INDEX(IDX_transaction_uid_deleted_type_time) NOT NULL"`
	CategoryId           int64             `xorm:"INDEX(IDX_transaction_uid_deleted_category_id_time) NOT NULL"`
	AccountId            int64             `xorm:"INDEX(IDX_transaction_uid_deleted_account_id_time) NOT NULL"`
	TransactionTime      int64             `xorm:"UNIQUE(UQE_transaction_uid_time) INDEX(IDX_transaction_uid_deleted_time) INDEX(IDX_transaction_uid_deleted_type_time) INDEX(IDX_transaction_uid_deleted_category_id_time) INDEX(IDX_transaction_uid_deleted_account_id_time) NOT NULL"`
	TimezoneUtcOffset    int16             `xorm:"NOT NULL"`
	Amount               int64             `xorm:"NOT NULL"`
	RelatedId            int64             `xorm:"NOT NULL"`
	RelatedAccountId     int64             `xorm:"NOT NULL"`
	RelatedAccountAmount int64             `xorm:"NOT NULL"`
	HideAmount           bool              `xorm:"NOT NULL"`
	Comment              string            `xorm:"VARCHAR(255) NOT NULL"`
	CreatedIp            string            `xorm:"VARCHAR(39)"`
	CreatedUnixTime      int64
	UpdatedUnixTime      int64
	DeletedUnixTime      int64
}

// TransactionCreateRequest represents all parameters of transaction creation request
type TransactionCreateRequest struct {
	Type                 TransactionType `json:"type" binding:"required"`
	CategoryId           int64           `json:"categoryId,string"`
	Time                 int64           `json:"time" binding:"required,min=1"`
	UtcOffset            int16           `json:"utcOffset" binding:"min=-720,max=840"`
	SourceAccountId      int64           `json:"sourceAccountId,string" binding:"required,min=1"`
	DestinationAccountId int64           `json:"destinationAccountId,string" binding:"min=0"`
	SourceAmount         int64           `json:"sourceAmount" binding:"min=-99999999999,max=99999999999"`
	DestinationAmount    int64           `json:"destinationAmount" binding:"min=-99999999999,max=99999999999"`
	HideAmount           bool            `json:"hideAmount"`
	TagIds               []string        `json:"tagIds"`
	Comment              string          `json:"comment" binding:"max=255"`
}

// TransactionModifyRequest represents all parameters of transaction modification request
type TransactionModifyRequest struct {
	Id                   int64    `json:"id,string" binding:"required,min=1"`
	CategoryId           int64    `json:"categoryId,string"`
	Time                 int64    `json:"time" binding:"required,min=1"`
	UtcOffset            int16    `json:"utcOffset" binding:"min=-720,max=840"`
	SourceAccountId      int64    `json:"sourceAccountId,string" binding:"required,min=1"`
	DestinationAccountId int64    `json:"destinationAccountId,string" binding:"min=0"`
	SourceAmount         int64    `json:"sourceAmount" binding:"min=-99999999999,max=99999999999"`
	DestinationAmount    int64    `json:"destinationAmount" binding:"min=-99999999999,max=99999999999"`
	HideAmount           bool     `json:"hideAmount"`
	TagIds               []string `json:"tagIds"`
	Comment              string   `json:"comment" binding:"max=255"`
}

// TransactionCountRequest represents transaction count request
type TransactionCountRequest struct {
	Type       TransactionDbType `form:"type" binding:"min=0,max=4"`
	CategoryId int64             `form:"category_id" binding:"min=0"`
	AccountId  int64             `form:"account_id" binding:"min=0"`
	Keyword    string            `form:"keyword"`
	MaxTime    int64             `form:"max_time" binding:"min=0"`
	MinTime    int64             `form:"min_time" binding:"min=0"`
}

// TransactionListByMaxTimeRequest represents all parameters of transaction listing by max time request
type TransactionListByMaxTimeRequest struct {
	Type         TransactionDbType `form:"type" binding:"min=0,max=4"`
	CategoryId   int64             `form:"category_id" binding:"min=0"`
	AccountId    int64             `form:"account_id" binding:"min=0"`
	Keyword      string            `form:"keyword"`
	MaxTime      int64             `form:"max_time" binding:"min=0"`
	MinTime      int64             `form:"min_time" binding:"min=0"`
	Count        int32             `form:"count" binding:"required,min=1,max=50"`
	TrimAccount  bool              `form:"trim_account"`
	TrimCategory bool              `form:"trim_category"`
	TrimTag      bool              `form:"trim_tag"`
}

// TransactionListInMonthByPageRequest represents all parameters of transaction listing by month request
type TransactionListInMonthByPageRequest struct {
	Year         int32             `form:"year" binding:"required,min=1"`
	Month        int32             `form:"month" binding:"required,min=1"`
	Type         TransactionDbType `form:"type" binding:"min=0,max=4"`
	CategoryId   int64             `form:"category_id" binding:"min=0"`
	AccountId    int64             `form:"account_id" binding:"min=0"`
	Keyword      string            `form:"keyword"`
	Page         int32             `form:"page" binding:"required,min=1"`
	Count        int32             `form:"count" binding:"required,min=1,max=50"`
	TrimAccount  bool              `form:"trim_account"`
	TrimCategory bool              `form:"trim_category"`
	TrimTag      bool              `form:"trim_tag"`
}

// TransactionStatisticRequest represents all parameters of transaction statistic request
type TransactionStatisticRequest struct {
	StartTime int64 `form:"start_time" binding:"min=0"`
	EndTime   int64 `form:"end_time" binding:"min=0"`
}

// TransactionAmountsRequest represents all parameters of transaction amounts request
type TransactionAmountsRequest struct {
	Query string `form:"query"`
}

// TransactionAmountsRequestItem represents an item of transaction amounts request
type TransactionAmountsRequestItem struct {
	Name      string
	StartTime int64
	EndTime   int64
}

// TransactionMonthAmountsRequest represents all parameters of transaction month amounts request
type TransactionMonthAmountsRequest struct {
	StartYearMonth string `form:"start_year_month"`
	EndYearMonth   string `form:"end_year_month"`
}

// TransactionGetRequest represents all parameters of transaction getting request
type TransactionGetRequest struct {
	Id           int64 `form:"id,string" binding:"required,min=1"`
	TrimAccount  bool  `form:"trim_account"`
	TrimCategory bool  `form:"trim_category"`
	TrimTag      bool  `form:"trim_tag"`
}

// TransactionDeleteRequest represents all parameters of transaction deleting request
type TransactionDeleteRequest struct {
	Id int64 `json:"id,string" binding:"required,min=1"`
}

// TransactionAccountsAmount represents transaction accounts amount map
type TransactionAccountsAmount map[int64]*TransactionAccountAmount

// TransactionAccountAmount represents transaction account amount
type TransactionAccountAmount struct {
	AccountId          int64
	TotalIncomeAmount  int64
	TotalExpenseAmount int64
}

// TransactionInfoResponse represents a view-object of transaction
type TransactionInfoResponse struct {
	Id                   int64                            `json:"id,string"`
	TimeSequenceId       int64                            `json:"timeSequenceId,string"`
	Type                 TransactionType                  `json:"type"`
	CategoryId           int64                            `json:"categoryId,string"`
	Category             *TransactionCategoryInfoResponse `json:"category,omitempty"`
	Time                 int64                            `json:"time"`
	UtcOffset            int16                            `json:"utcOffset"`
	SourceAccountId      int64                            `json:"sourceAccountId,string"`
	SourceAccount        *AccountInfoResponse             `json:"sourceAccount,omitempty"`
	DestinationAccountId int64                            `json:"destinationAccountId,string,omitempty"`
	DestinationAccount   *AccountInfoResponse             `json:"destinationAccount,omitempty"`
	SourceAmount         int64                            `json:"sourceAmount"`
	DestinationAmount    int64                            `json:"destinationAmount,omitempty"`
	HideAmount           bool                             `json:"hideAmount"`
	TagIds               []string                         `json:"tagIds"`
	Tags                 []*TransactionTagInfoResponse    `json:"tags,omitempty"`
	Comment              string                           `json:"comment"`
	Editable             bool                             `json:"editable"`
}

// TransactionCountResponse represents transaction count response
type TransactionCountResponse struct {
	TotalCount int64 `json:"totalCount"`
}

// TransactionInfoPageWrapperResponse represents a response of transaction which contains items and next id
type TransactionInfoPageWrapperResponse struct {
	Items              TransactionInfoResponseSlice `json:"items"`
	NextTimeSequenceId *int64                       `json:"nextTimeSequenceId,string"`
}

// TransactionInfoPageWrapperResponse2 represents a response of transaction which contains items and count
type TransactionInfoPageWrapperResponse2 struct {
	Items      TransactionInfoResponseSlice `json:"items"`
	TotalCount int64                        `json:"totalCount"`
}

// TransactionStatisticResponse represents an item of transaction amounts
type TransactionStatisticResponse struct {
	StartTime int64                               `json:"startTime"`
	EndTime   int64                               `json:"endTime"`
	Items     []*TransactionStatisticResponseItem `json:"items"`
}

// TransactionStatisticResponseItem represents total amount item for an response
type TransactionStatisticResponseItem struct {
	CategoryId  int64 `json:"categoryId,string"`
	AccountId   int64 `json:"accountId,string"`
	TotalAmount int64 `json:"amount"`
}

// TransactionAmountsResponseItem represents an item of transaction amounts
type TransactionAmountsResponseItem struct {
	StartTime int64                                       `json:"startTime"`
	EndTime   int64                                       `json:"endTime"`
	Amounts   []*TransactionAmountsResponseItemAmountInfo `json:"amounts"`
}

// TransactionMonthAmountsResponseItem represents an item of transaction month amounts
type TransactionMonthAmountsResponseItem struct {
	Year    int32                                       `json:"year"`
	Month   int32                                       `json:"month"`
	Amounts []*TransactionAmountsResponseItemAmountInfo `json:"amounts"`
}

// TransactionAmountsResponseItemAmountInfo represents amount info for an response item
type TransactionAmountsResponseItemAmountInfo struct {
	Currency      string `json:"currency"`
	IncomeAmount  int64  `json:"incomeAmount"`
	ExpenseAmount int64  `json:"expenseAmount"`
}

// IsEditable returns whether this transaction can be edited
func (t *Transaction) IsEditable(currentUser *User, utcOffset int16, account *Account, relatedAccount *Account) bool {
	if currentUser == nil || !currentUser.CanEditTransactionByTransactionTime(t.TransactionTime, utcOffset) {
		return false
	}

	if account == nil || account.Hidden {
		return false
	}

	if t.Type == TRANSACTION_DB_TYPE_TRANSFER_OUT {
		if relatedAccount == nil || relatedAccount.Hidden {
			return false
		}
	}

	return true
}

// ToTransactionInfoResponse returns a view-object according to database model
func (t *Transaction) ToTransactionInfoResponse(tagIds []int64, editable bool) *TransactionInfoResponse {
	var transactionType TransactionType

	if t.Type == TRANSACTION_DB_TYPE_MODIFY_BALANCE {
		transactionType = TRANSACTION_TYPE_MODIFY_BALANCE
	} else if t.Type == TRANSACTION_DB_TYPE_EXPENSE {
		transactionType = TRANSACTION_TYPE_EXPENSE
	} else if t.Type == TRANSACTION_DB_TYPE_INCOME {
		transactionType = TRANSACTION_TYPE_INCOME
	} else if t.Type == TRANSACTION_DB_TYPE_TRANSFER_OUT {
		transactionType = TRANSACTION_TYPE_TRANSFER
	} else if t.Type == TRANSACTION_DB_TYPE_TRANSFER_IN {
		transactionType = TRANSACTION_TYPE_TRANSFER
	} else {
		return nil
	}

	sourceAccountId := t.AccountId
	sourceAmount := t.Amount

	destinationAccountId := int64(0)
	destinationAmount := int64(0)

	if t.Type == TRANSACTION_DB_TYPE_TRANSFER_OUT {
		destinationAccountId = t.RelatedAccountId
		destinationAmount = t.RelatedAccountAmount
	} else if t.Type == TRANSACTION_DB_TYPE_TRANSFER_IN {
		sourceAccountId = t.RelatedAccountId
		sourceAmount = t.RelatedAccountAmount

		destinationAccountId = t.AccountId
		destinationAmount = t.Amount
	}

	return &TransactionInfoResponse{
		Id:                   t.TransactionId,
		TimeSequenceId:       t.TransactionTime,
		Type:                 transactionType,
		CategoryId:           t.CategoryId,
		Time:                 utils.GetUnixTimeFromTransactionTime(t.TransactionTime),
		UtcOffset:            t.TimezoneUtcOffset,
		SourceAccountId:      sourceAccountId,
		DestinationAccountId: destinationAccountId,
		SourceAmount:         sourceAmount,
		DestinationAmount:    destinationAmount,
		HideAmount:           t.HideAmount,
		TagIds:               utils.Int64ArrayToStringArray(tagIds),
		Comment:              t.Comment,
		Editable:             editable,
	}
}

// GetTransactionAmountsRequestItems returns request items by query parameters
func (t *TransactionAmountsRequest) GetTransactionAmountsRequestItems() ([]*TransactionAmountsRequestItem, error) {
	items := strings.Split(t.Query, "|")
	requestItems := make([]*TransactionAmountsRequestItem, 0, len(items))

	for i := 0; i < len(items); i++ {
		itemValues := strings.Split(items[i], "_")

		if len(itemValues) != 3 {
			return nil, errs.ErrQueryItemsInvalid
		}

		startTime, err := utils.StringToInt64(itemValues[1])

		if err != nil {
			return nil, err
		}

		endTime, err := utils.StringToInt64(itemValues[2])

		if err != nil {
			return nil, err
		}

		requestItem := &TransactionAmountsRequestItem{
			Name:      itemValues[0],
			StartTime: startTime,
			EndTime:   endTime,
		}

		requestItems = append(requestItems, requestItem)
	}

	return requestItems, nil
}

// GetStartTimeAndEndTime returns start unix time and end unix time by request parameter
func (t *TransactionMonthAmountsRequest) GetStartTimeAndEndTime(utcOffset int16) (int64, int64, error) {
	startUnixTime := int64(0)
	endUnixTime := time.Now().Unix()

	if t.StartYearMonth != "" {
		startTime, err := utils.ParseFromShortDateTime(fmt.Sprintf("%s-1 0:0:0", t.StartYearMonth), utcOffset)

		if err != nil {
			return 0, 0, err
		}

		startUnixTime = startTime.Unix()
	}

	if t.EndYearMonth != "" {
		endTime, err := utils.ParseFromShortDateTime(fmt.Sprintf("%s-1 0:0:0", t.EndYearMonth), utcOffset)

		if err != nil {
			return 0, 0, err
		}

		endTime = endTime.AddDate(0, 1, 0)
		endUnixTime = endTime.Unix() - 1
	}

	return startUnixTime, endUnixTime, nil
}

// TransactionInfoResponseSlice represents the slice data structure of TransactionInfoResponse
type TransactionInfoResponseSlice []*TransactionInfoResponse

// Len returns the count of items
func (s TransactionInfoResponseSlice) Len() int {
	return len(s)
}

// Swap swaps two items
func (s TransactionInfoResponseSlice) Swap(i, j int) {
	s[i], s[j] = s[j], s[i]
}

// Less reports whether the first item is less than the second one
func (s TransactionInfoResponseSlice) Less(i, j int) bool {
	if s[i].Time != s[j].Time {
		return s[i].Time > s[j].Time
	}

	return s[i].Id > s[j].Id
}

// TransactionMonthAmountsResponseItemSlice represents the slice data structure of TransactionMonthAmountsResponseItem
type TransactionMonthAmountsResponseItemSlice []*TransactionMonthAmountsResponseItem

// Len returns the count of items
func (s TransactionMonthAmountsResponseItemSlice) Len() int {
	return len(s)
}

// Swap swaps two items
func (s TransactionMonthAmountsResponseItemSlice) Swap(i, j int) {
	s[i], s[j] = s[j], s[i]
}

// Less reports whether the first item is less than the second one
func (s TransactionMonthAmountsResponseItemSlice) Less(i, j int) bool {
	if s[i].Year != s[j].Year {
		return s[i].Year > s[j].Year
	}

	return s[i].Month > s[j].Month
}