package api

import (
	"sort"
	"strings"

	"github.com/mayswind/ezbookkeeping/pkg/core"
	"github.com/mayswind/ezbookkeeping/pkg/duplicatechecker"
	"github.com/mayswind/ezbookkeeping/pkg/errs"
	"github.com/mayswind/ezbookkeeping/pkg/log"
	"github.com/mayswind/ezbookkeeping/pkg/models"
	"github.com/mayswind/ezbookkeeping/pkg/services"
	"github.com/mayswind/ezbookkeeping/pkg/settings"
	"github.com/mayswind/ezbookkeeping/pkg/utils"
)

// TransactionTemplatesApi represents transaction template api
type TransactionTemplatesApi struct {
	templates *services.TransactionTemplateService
}

// Initialize a transaction template api singleton instance
var (
	TransactionTemplates = &TransactionTemplatesApi{
		templates: services.TransactionTemplates,
	}
)

// TemplateListHandler returns transaction template list of current user
func (a *TransactionTemplatesApi) TemplateListHandler(c *core.Context) (any, *errs.Error) {
	var templateListReq models.TransactionTemplateListRequest
	err := c.ShouldBindQuery(&templateListReq)

	if err != nil {
		log.WarnfWithRequestId(c, "[transaction_templates.TemplateListHandler] parse request failed, because %s", err.Error())
		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
	}

	uid := c.GetCurrentUid()
	templates, err := a.templates.GetAllTemplatesByUid(c, uid, templateListReq.TemplateType)

	if err != nil {
		log.ErrorfWithRequestId(c, "[transaction_templates.TemplateListHandler] failed to get templates for user \"uid:%d\", because %s", uid, err.Error())
		return nil, errs.Or(err, errs.ErrOperationFailed)
	}

	templateResps := make(models.TransactionTemplateInfoResponseSlice, len(templates))
	serverUtcOffset := utils.GetServerTimezoneOffsetMinutes()

	for i := 0; i < len(templates); i++ {
		templateResps[i] = templates[i].ToTransactionTemplateInfoResponse(serverUtcOffset)
	}

	sort.Sort(templateResps)

	return templateResps, nil
}

// TemplateGetHandler returns one specific transaction template of current user
func (a *TransactionTemplatesApi) TemplateGetHandler(c *core.Context) (any, *errs.Error) {
	var templateGetReq models.TransactionTemplateGetRequest
	err := c.ShouldBindQuery(&templateGetReq)

	if err != nil {
		log.WarnfWithRequestId(c, "[transaction_templates.TemplateGetHandler] parse request failed, because %s", err.Error())
		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
	}

	uid := c.GetCurrentUid()
	template, err := a.templates.GetTemplateByTemplateId(c, uid, templateGetReq.Id)

	if err != nil {
		log.ErrorfWithRequestId(c, "[transaction_templates.TemplateGetHandler] failed to get template \"id:%d\" for user \"uid:%d\", because %s", templateGetReq.Id, uid, err.Error())
		return nil, errs.Or(err, errs.ErrOperationFailed)
	}

	serverUtcOffset := utils.GetServerTimezoneOffsetMinutes()
	templateResp := template.ToTransactionTemplateInfoResponse(serverUtcOffset)

	return templateResp, nil
}

// TemplateCreateHandler saves a new transaction template by request parameters for current user
func (a *TransactionTemplatesApi) TemplateCreateHandler(c *core.Context) (any, *errs.Error) {
	var templateCreateReq models.TransactionTemplateCreateRequest
	err := c.ShouldBindJSON(&templateCreateReq)

	if err != nil {
		log.WarnfWithRequestId(c, "[transaction_templates.TemplateCreateHandler] parse request failed, because %s", err.Error())
		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
	}

	uid := c.GetCurrentUid()

	maxOrderId, err := a.templates.GetMaxDisplayOrder(c, uid, templateCreateReq.TemplateType)

	if err != nil {
		log.ErrorfWithRequestId(c, "[transaction_templates.TemplateCreateHandler] failed to get max display order for user \"uid:%d\", because %s", uid, err.Error())
		return nil, errs.Or(err, errs.ErrOperationFailed)
	}

	serverUtcOffset := utils.GetServerTimezoneOffsetMinutes()
	template := a.createNewTemplateModel(uid, &templateCreateReq, maxOrderId+1)

	if settings.Container.Current.EnableDuplicateSubmissionsCheck && templateCreateReq.ClientSessionId != "" {
		found, remark := duplicatechecker.Container.Get(duplicatechecker.DUPLICATE_CHECKER_TYPE_NEW_TEMPLATE, uid, templateCreateReq.ClientSessionId)

		if found {
			log.InfofWithRequestId(c, "[transaction_templates.TemplateCreateHandler] another template \"id:%s\" has been created for user \"uid:%d\"", remark, uid)
			templateId, err := utils.StringToInt64(remark)

			if err == nil {
				template, err = a.templates.GetTemplateByTemplateId(c, uid, templateId)

				if err != nil {
					log.ErrorfWithRequestId(c, "[transaction_templates.TemplateCreateHandler] failed to get existed template \"id:%d\" for user \"uid:%d\", because %s", templateId, uid, err.Error())
					return nil, errs.Or(err, errs.ErrOperationFailed)
				}

				templateResp := template.ToTransactionTemplateInfoResponse(serverUtcOffset)

				return templateResp, nil
			}
		}
	}

	err = a.templates.CreateTemplate(c, template)

	if err != nil {
		log.ErrorfWithRequestId(c, "[transaction_templates.TemplateCreateHandler] failed to create template \"id:%d\" for user \"uid:%d\", because %s", template.TemplateId, uid, err.Error())
		return nil, errs.Or(err, errs.ErrOperationFailed)
	}

	log.InfofWithRequestId(c, "[transaction_templates.TemplateCreateHandler] user \"uid:%d\" has created a new template \"id:%d\" successfully", uid, template.TemplateId)

	duplicatechecker.Container.Set(duplicatechecker.DUPLICATE_CHECKER_TYPE_NEW_TEMPLATE, uid, templateCreateReq.ClientSessionId, utils.Int64ToString(template.TemplateId))
	templateResp := template.ToTransactionTemplateInfoResponse(serverUtcOffset)

	return templateResp, nil
}

// TemplateModifyNameHandler updates the name of an existed transaction template by request parameters for current user
func (a *TransactionTemplatesApi) TemplateModifyNameHandler(c *core.Context) (any, *errs.Error) {
	var templateModifyReq models.TransactionTemplateModifyNameRequest
	err := c.ShouldBindJSON(&templateModifyReq)

	if err != nil {
		log.WarnfWithRequestId(c, "[transaction_templates.TemplateModifyNameHandler] parse request failed, because %s", err.Error())
		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
	}

	uid := c.GetCurrentUid()
	template, err := a.templates.GetTemplateByTemplateId(c, uid, templateModifyReq.Id)

	if err != nil {
		log.ErrorfWithRequestId(c, "[transaction_templates.TemplateModifyNameHandler] failed to get template \"id:%d\" for user \"uid:%d\", because %s", templateModifyReq.Id, uid, err.Error())
		return nil, errs.Or(err, errs.ErrOperationFailed)
	}

	if templateModifyReq.Name == template.Name {
		return nil, errs.ErrNothingWillBeUpdated
	}

	newTemplate := &models.TransactionTemplate{
		TemplateId: template.TemplateId,
		Uid:        template.Uid,
		Name:       templateModifyReq.Name,
	}

	err = a.templates.ModifyTemplateName(c, newTemplate)

	if err != nil {
		log.ErrorfWithRequestId(c, "[transaction_templates.TemplateModifyNameHandler] failed to update template \"id:%d\" for user \"uid:%d\", because %s", templateModifyReq.Id, uid, err.Error())
		return nil, errs.Or(err, errs.ErrOperationFailed)
	}

	log.InfofWithRequestId(c, "[transaction_templates.TemplateModifyNameHandler] user \"uid:%d\" has updated template \"id:%d\" successfully", uid, templateModifyReq.Id)

	serverUtcOffset := utils.GetServerTimezoneOffsetMinutes()
	template.Name = newTemplate.Name
	templateResp := template.ToTransactionTemplateInfoResponse(serverUtcOffset)

	return templateResp, nil
}

// TemplateModifyHandler saves an existed transaction template by request parameters for current user
func (a *TransactionTemplatesApi) TemplateModifyHandler(c *core.Context) (any, *errs.Error) {
	var templateModifyReq models.TransactionTemplateModifyRequest
	err := c.ShouldBindJSON(&templateModifyReq)

	if err != nil {
		log.WarnfWithRequestId(c, "[transaction_templates.TemplateModifyHandler] parse request failed, because %s", err.Error())
		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
	}

	uid := c.GetCurrentUid()
	template, err := a.templates.GetTemplateByTemplateId(c, uid, templateModifyReq.Id)

	if err != nil {
		log.ErrorfWithRequestId(c, "[transaction_templates.TemplateModifyHandler] failed to get template \"id:%d\" for user \"uid:%d\", because %s", templateModifyReq.Id, uid, err.Error())
		return nil, errs.Or(err, errs.ErrOperationFailed)
	}

	newTemplate := &models.TransactionTemplate{
		TemplateId:           template.TemplateId,
		Uid:                  uid,
		Type:                 templateModifyReq.Type,
		CategoryId:           templateModifyReq.CategoryId,
		AccountId:            templateModifyReq.SourceAccountId,
		TagIds:               strings.Join(templateModifyReq.TagIds, ","),
		Amount:               templateModifyReq.SourceAmount,
		RelatedAccountId:     templateModifyReq.DestinationAccountId,
		RelatedAccountAmount: templateModifyReq.DestinationAmount,
		Comment:              templateModifyReq.Comment,
	}

	if newTemplate.Type == template.Type &&
		newTemplate.CategoryId == template.CategoryId &&
		newTemplate.AccountId == template.AccountId &&
		newTemplate.TagIds == template.TagIds &&
		newTemplate.Amount == template.Amount &&
		newTemplate.RelatedAccountId == template.RelatedAccountId &&
		newTemplate.RelatedAccountAmount == template.RelatedAccountAmount &&
		newTemplate.Comment == template.Comment {
		return nil, errs.ErrNothingWillBeUpdated
	}

	err = a.templates.ModifyTemplate(c, newTemplate)

	if err != nil {
		log.ErrorfWithRequestId(c, "[transaction_templates.TemplateModifyHandler] failed to update template \"id:%d\" for user \"uid:%d\", because %s", templateModifyReq.Id, uid, err.Error())
		return nil, errs.Or(err, errs.ErrOperationFailed)
	}

	log.InfofWithRequestId(c, "[transaction_templates.TemplateModifyHandler] user \"uid:%d\" has updated template \"id:%d\" successfully", uid, templateModifyReq.Id)

	serverUtcOffset := utils.GetServerTimezoneOffsetMinutes()
	newTemplate.Name = template.Name
	newTemplate.DisplayOrder = template.DisplayOrder
	newTemplate.Hidden = template.Hidden
	templateResp := newTemplate.ToTransactionTemplateInfoResponse(serverUtcOffset)

	return templateResp, nil
}

// TemplateHideHandler hides an transaction template by request parameters for current user
func (a *TransactionTemplatesApi) TemplateHideHandler(c *core.Context) (any, *errs.Error) {
	var templateHideReq models.TransactionTemplateHideRequest
	err := c.ShouldBindJSON(&templateHideReq)

	if err != nil {
		log.WarnfWithRequestId(c, "[transaction_templates.TemplateHideHandler] parse request failed, because %s", err.Error())
		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
	}

	uid := c.GetCurrentUid()
	err = a.templates.HideTemplate(c, uid, []int64{templateHideReq.Id}, templateHideReq.Hidden)

	if err != nil {
		log.ErrorfWithRequestId(c, "[transaction_templates.TemplateHideHandler] failed to hide template \"id:%d\" for user \"uid:%d\", because %s", templateHideReq.Id, uid, err.Error())
		return nil, errs.Or(err, errs.ErrOperationFailed)
	}

	log.InfofWithRequestId(c, "[transaction_templates.TemplateHideHandler] user \"uid:%d\" has hidden template \"id:%d\"", uid, templateHideReq.Id)
	return true, nil
}

// TemplateMoveHandler moves display order of existed transaction templates by request parameters for current user
func (a *TransactionTemplatesApi) TemplateMoveHandler(c *core.Context) (any, *errs.Error) {
	var templateMoveReq models.TransactionTemplateMoveRequest
	err := c.ShouldBindJSON(&templateMoveReq)

	if err != nil {
		log.WarnfWithRequestId(c, "[transaction_templates.CategoryMoveHandler] parse request failed, because %s", err.Error())
		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
	}

	uid := c.GetCurrentUid()
	templates := make([]*models.TransactionTemplate, len(templateMoveReq.NewDisplayOrders))

	for i := 0; i < len(templateMoveReq.NewDisplayOrders); i++ {
		newDisplayOrder := templateMoveReq.NewDisplayOrders[i]
		template := &models.TransactionTemplate{
			Uid:          uid,
			TemplateId:   newDisplayOrder.Id,
			DisplayOrder: newDisplayOrder.DisplayOrder,
		}

		templates[i] = template
	}

	err = a.templates.ModifyTemplateDisplayOrders(c, uid, templates)

	if err != nil {
		log.ErrorfWithRequestId(c, "[transaction_templates.TemplateMoveHandler] failed to move templates for user \"uid:%d\", because %s", uid, err.Error())
		return nil, errs.Or(err, errs.ErrOperationFailed)
	}

	log.InfofWithRequestId(c, "[transaction_templates.TemplateMoveHandler] user \"uid:%d\" has moved templates", uid)
	return true, nil
}

// TemplateDeleteHandler deletes an existed transaction template by request parameters for current user
func (a *TransactionTemplatesApi) TemplateDeleteHandler(c *core.Context) (any, *errs.Error) {
	var templateDeleteReq models.TransactionTemplateDeleteRequest
	err := c.ShouldBindJSON(&templateDeleteReq)

	if err != nil {
		log.WarnfWithRequestId(c, "[transaction_templates.TemplateDeleteHandler] parse request failed, because %s", err.Error())
		return nil, errs.NewIncompleteOrIncorrectSubmissionError(err)
	}

	uid := c.GetCurrentUid()
	err = a.templates.DeleteTemplate(c, uid, templateDeleteReq.Id)

	if err != nil {
		log.ErrorfWithRequestId(c, "[transaction_templates.TemplateDeleteHandler] failed to delete template \"id:%d\" for user \"uid:%d\", because %s", templateDeleteReq.Id, uid, err.Error())
		return nil, errs.Or(err, errs.ErrOperationFailed)
	}

	log.InfofWithRequestId(c, "[transaction_templates.TemplateDeleteHandler] user \"uid:%d\" has deleted template \"id:%d\"", uid, templateDeleteReq.Id)
	return true, nil
}

func (a *TransactionTemplatesApi) createNewTemplateModel(uid int64, templateCreateReq *models.TransactionTemplateCreateRequest, order int32) *models.TransactionTemplate {
	return &models.TransactionTemplate{
		Uid:          uid,
		TemplateType: templateCreateReq.TemplateType,
		Name:         templateCreateReq.Name,
		Type:         models.TRANSACTION_TYPE_EXPENSE,
		DisplayOrder: order,
	}
}