package core

import (
	"database/sql"
	"net/http"
	"time"

	"github.com/gofrs/uuid"
	"github.com/jmoiron/sqlx"
	"github.com/knadh/listmonk/models"
	"github.com/labstack/echo/v4"
	"github.com/lib/pq"
)

const (
	CampaignAnalyticsViews   = "views"
	CampaignAnalyticsClicks  = "clicks"
	CampaignAnalyticsBounces = "bounces"
)

// QueryCampaigns retrieves paginated campaigns optionally filtering them by the given arbitrary
// query expression. It also returns the total number of records in the DB.
func (c *Core) QueryCampaigns(searchStr string, statuses []string, orderBy, order string, offset, limit int) (models.Campaigns, int, error) {
	queryStr, stmt := makeSearchQuery(searchStr, orderBy, order, c.q.QueryCampaigns)

	if statuses == nil {
		statuses = []string{}
	}

	// Unsafe to ignore scanning fields not present in models.Campaigns.
	var out models.Campaigns
	if err := c.db.Select(&out, stmt, 0, pq.Array(statuses), queryStr, offset, limit); err != nil {
		c.log.Printf("error fetching campaigns: %v", err)
		return nil, 0, echo.NewHTTPError(http.StatusInternalServerError,
			c.i18n.Ts("globals.messages.errorFetching", "name", "{globals.terms.campaign}", "error", pqErrMsg(err)))
	}

	for i := 0; i < len(out); i++ {
		// Replace null tags.
		if out[i].Tags == nil {
			out[i].Tags = []string{}
		}
	}

	// Lazy load stats.
	if err := out.LoadStats(c.q.GetCampaignStats); err != nil {
		c.log.Printf("error fetching campaign stats: %v", err)
		return nil, 0, echo.NewHTTPError(http.StatusInternalServerError,
			c.i18n.Ts("globals.messages.errorFetching", "name", "{globals.terms.campaigns}", "error", pqErrMsg(err)))
	}

	total := 0
	if len(out) > 0 {
		total = out[0].Total
	}

	return out, total, nil
}

// GetCampaign retrieves a campaign.
func (c *Core) GetCampaign(id int, uuid string) (models.Campaign, error) {
	// Unsafe to ignore scanning fields not present in models.Campaigns.
	var uu interface{}
	if uuid != "" {
		uu = uuid
	}

	var out models.Campaigns
	if err := c.q.GetCampaign.Select(&out, id, uu); err != nil {
		// if err := c.db.Select(&out, stmt, 0, pq.Array([]string{}), queryStr, 0, 1); err != nil {
		c.log.Printf("error fetching campaign: %v", err)
		return models.Campaign{}, echo.NewHTTPError(http.StatusInternalServerError,
			c.i18n.Ts("globals.messages.errorFetching", "name", "{globals.terms.campaign}", "error", pqErrMsg(err)))
	}

	if len(out) == 0 {
		return models.Campaign{}, echo.NewHTTPError(http.StatusBadRequest,
			c.i18n.Ts("globals.messages.notFound", "name", "{globals.terms.campaign}"))

	}

	for i := 0; i < len(out); i++ {
		// Replace null tags.
		if out[i].Tags == nil {
			out[i].Tags = []string{}
		}
	}

	// Lazy load stats.
	if err := out.LoadStats(c.q.GetCampaignStats); err != nil {
		c.log.Printf("error fetching campaign stats: %v", err)
		return models.Campaign{}, echo.NewHTTPError(http.StatusInternalServerError,
			c.i18n.Ts("globals.messages.errorFetching", "name", "{globals.terms.campaign}", "error", pqErrMsg(err)))
	}

	return out[0], nil
}

// GetCampaignForPreview retrieves a campaign with a template body.
func (c *Core) GetCampaignForPreview(id, tplID int) (models.Campaign, error) {
	var out models.Campaign
	if err := c.q.GetCampaignForPreview.Get(&out, id, tplID); err != nil {
		if err == sql.ErrNoRows {
			return models.Campaign{}, echo.NewHTTPError(http.StatusBadRequest,
				c.i18n.Ts("globals.messages.notFound", "name", "{globals.terms.campaign}"))
		}

		c.log.Printf("error fetching campaign: %v", err)
		return models.Campaign{}, echo.NewHTTPError(http.StatusInternalServerError,
			c.i18n.Ts("globals.messages.errorFetching", "name", "{globals.terms.campaign}", "error", pqErrMsg(err)))
	}

	return out, nil
}

// CreateCampaign creates a new campaign.
func (c *Core) CreateCampaign(o models.Campaign, listIDs []int) (models.Campaign, error) {
	uu, err := uuid.NewV4()
	if err != nil {
		c.log.Printf("error generating UUID: %v", err)
		return models.Campaign{}, echo.NewHTTPError(http.StatusInternalServerError,
			c.i18n.Ts("globals.messages.errorUUID", "error", err.Error()))
	}

	// Insert and read ID.
	var newID int
	if err := c.q.CreateCampaign.Get(&newID,
		uu,
		o.Type,
		o.Name,
		o.Subject,
		o.FromEmail,
		o.Body,
		o.AltBody,
		o.ContentType,
		o.SendAt,
		o.Headers,
		pq.StringArray(normalizeTags(o.Tags)),
		o.Messenger,
		o.TemplateID,
		pq.Array(listIDs),
	); err != nil {
		if err == sql.ErrNoRows {
			return models.Campaign{}, echo.NewHTTPError(http.StatusBadRequest, c.i18n.T("campaigns.noSubs"))
		}

		c.log.Printf("error creating campaign: %v", err)
		return models.Campaign{}, echo.NewHTTPError(http.StatusInternalServerError,
			c.i18n.Ts("globals.messages.errorCreating", "name", "{globals.terms.campaign}", "error", pqErrMsg(err)))
	}

	out, err := c.GetCampaign(newID, "")
	if err != nil {
		return models.Campaign{}, err
	}

	return out, nil
}

// UpdateCampaign updates a campaign.
func (c *Core) UpdateCampaign(id int, o models.Campaign, listIDs []int, sendLater bool) (models.Campaign, error) {
	_, err := c.q.UpdateCampaign.Exec(id,
		o.Name,
		o.Subject,
		o.FromEmail,
		o.Body,
		o.AltBody,
		o.ContentType,
		o.SendAt,
		sendLater,
		o.Headers,
		pq.StringArray(normalizeTags(o.Tags)),
		o.Messenger,
		o.TemplateID,
		pq.Array(listIDs))
	if err != nil {
		c.log.Printf("error updating campaign: %v", err)
		return models.Campaign{}, echo.NewHTTPError(http.StatusInternalServerError,
			c.i18n.Ts("globals.messages.errorUpdating", "name", "{globals.terms.campaign}", "error", pqErrMsg(err)))
	}

	out, err := c.GetCampaign(id, "")
	if err != nil {
		return models.Campaign{}, err
	}

	return out, nil
}

// UpdateCampaignStatus updates a campaign's status, eg: draft to running.
func (c *Core) UpdateCampaignStatus(id int, status string) (models.Campaign, error) {
	cm, err := c.GetCampaign(id, "")
	if err != nil {
		return models.Campaign{}, err
	}

	errMsg := ""
	switch status {
	case models.CampaignStatusDraft:
		if cm.Status != models.CampaignStatusScheduled {
			errMsg = c.i18n.T("campaigns.onlyScheduledAsDraft")
		}
	case models.CampaignStatusScheduled:
		if cm.Status != models.CampaignStatusDraft {
			errMsg = c.i18n.T("campaigns.onlyDraftAsScheduled")
		}
		if !cm.SendAt.Valid {
			errMsg = c.i18n.T("campaigns.needsSendAt")
		}

	case models.CampaignStatusRunning:
		if cm.Status != models.CampaignStatusPaused && cm.Status != models.CampaignStatusDraft {
			errMsg = c.i18n.T("campaigns.onlyPausedDraft")
		}
	case models.CampaignStatusPaused:
		if cm.Status != models.CampaignStatusRunning {
			errMsg = c.i18n.T("campaigns.onlyActivePause")
		}
	case models.CampaignStatusCancelled:
		if cm.Status != models.CampaignStatusRunning && cm.Status != models.CampaignStatusPaused {
			errMsg = c.i18n.T("campaigns.onlyActiveCancel")
		}
	case models.CampaignStatusFinished:
		if cm.Status != models.CampaignStatusRunning && cm.Status != models.CampaignStatusPaused {
			errMsg = c.i18n.T("campaigns.onlyActiveCancel")
		}
	}

	if len(errMsg) > 0 {
		return models.Campaign{}, echo.NewHTTPError(http.StatusBadRequest, errMsg)
	}

	res, err := c.q.UpdateCampaignStatus.Exec(cm.ID, status)
	if err != nil {
		c.log.Printf("error updating campaign status: %v", err)

		return models.Campaign{}, echo.NewHTTPError(http.StatusInternalServerError,
			c.i18n.Ts("globals.messages.errorUpdating", "name", "{globals.terms.campaign}", "error", pqErrMsg(err)))
	}

	if n, _ := res.RowsAffected(); n == 0 {
		return models.Campaign{}, echo.NewHTTPError(http.StatusBadRequest,
			c.i18n.Ts("globals.messages.notFound", "name", "{globals.terms.campaign}", "error", pqErrMsg(err)))
	}

	cm.Status = status
	return cm, nil
}

// DeleteCampaign deletes a campaign.
func (c *Core) DeleteCampaign(id int) error {
	res, err := c.q.DeleteCampaign.Exec(id)
	if err != nil {
		c.log.Printf("error deleting campaign: %v", err)
		return echo.NewHTTPError(http.StatusInternalServerError,
			c.i18n.Ts("globals.messages.errorDeleting", "name", "{globals.terms.campaign}", "error", pqErrMsg(err)))

	}

	if n, _ := res.RowsAffected(); n == 0 {
		return echo.NewHTTPError(http.StatusBadRequest,
			c.i18n.Ts("globals.messages.notFound", "name", "{globals.terms.campaign}"))
	}

	return nil
}

// GetRunningCampaignStats returns the progress stats of running campaigns.
func (c *Core) GetRunningCampaignStats() ([]models.CampaignStats, error) {
	out := []models.CampaignStats{}
	if err := c.q.GetCampaignStatus.Select(&out, models.CampaignStatusRunning); err != nil {
		if err == sql.ErrNoRows {
			return nil, nil
		}

		c.log.Printf("error fetching campaign stats: %v", err)
		return nil, echo.NewHTTPError(http.StatusInternalServerError,
			c.i18n.Ts("globals.messages.errorFetching", "name", "{globals.terms.campaign}", "error", pqErrMsg(err)))
	} else if len(out) == 0 {
		return nil, nil
	}

	return out, nil
}

func (c *Core) GetCampaignAnalyticsCounts(campIDs []int, typ, fromDate, toDate string) ([]models.CampaignAnalyticsCount, error) {
	// Pick campaign view counts or click counts.
	var stmt *sqlx.Stmt
	switch typ {
	case "views":
		stmt = c.q.GetCampaignViewCounts
	case "clicks":
		stmt = c.q.GetCampaignClickCounts
	case "bounces":
		stmt = c.q.GetCampaignBounceCounts
	default:
		return nil, echo.NewHTTPError(http.StatusBadRequest, c.i18n.T("globals.messages.invalidData"))
	}

	if !strHasLen(fromDate, 10, 30) || !strHasLen(toDate, 10, 30) {
		return nil, echo.NewHTTPError(http.StatusBadRequest, c.i18n.T("analytics.invalidDates"))
	}

	out := []models.CampaignAnalyticsCount{}
	if err := stmt.Select(&out, pq.Array(campIDs), fromDate, toDate); err != nil {
		c.log.Printf("error fetching campaign %s: %v", typ, err)
		return nil, echo.NewHTTPError(http.StatusInternalServerError,
			c.i18n.Ts("globals.messages.errorFetching", "name", "{globals.terms.analytics}", "error", pqErrMsg(err)))
	}

	return out, nil
}

// GetCampaignAnalyticsLinks returns link click analytics for the given campaign IDs.
func (c *Core) GetCampaignAnalyticsLinks(campIDs []int, typ, fromDate, toDate string) ([]models.CampaignAnalyticsLink, error) {
	out := []models.CampaignAnalyticsLink{}
	if err := c.q.GetCampaignLinkCounts.Select(&out, pq.Array(campIDs), fromDate, toDate); err != nil {
		c.log.Printf("error fetching campaign %s: %v", typ, err)
		return nil, echo.NewHTTPError(http.StatusInternalServerError,
			c.i18n.Ts("globals.messages.errorFetching", "name", "{globals.terms.analytics}", "error", pqErrMsg(err)))
	}

	return out, nil
}

// RegisterCampaignView registers a subscriber's view on a campaign.
func (c *Core) RegisterCampaignView(campUUID, subUUID string) error {
	if _, err := c.q.RegisterCampaignView.Exec(campUUID, subUUID); err != nil {
		c.log.Printf("error registering campaign view: %s", err)
		return echo.NewHTTPError(http.StatusInternalServerError,
			c.i18n.Ts("globals.messages.errorUpdating", "name", "{globals.terms.campaign}", "error", pqErrMsg(err)))
	}
	return nil
}

// RegisterCampaignLinkClick registers a subscriber's link click on a campaign.
func (c *Core) RegisterCampaignLinkClick(linkUUID, campUUID, subUUID string) (string, error) {
	var url string
	if err := c.q.RegisterLinkClick.Get(&url, linkUUID, campUUID, subUUID); err != nil {
		if pqErr, ok := err.(*pq.Error); ok && pqErr.Column == "link_id" {
			return "", echo.NewHTTPError(http.StatusBadRequest, c.i18n.Ts("public.invalidLink"))
		}

		c.log.Printf("error registering link click: %s", err)
		return "", echo.NewHTTPError(http.StatusInternalServerError, c.i18n.Ts("public.errorProcessingRequest"))
	}

	return url, nil
}

// DeleteCampaignViews deletes campaign views older than a given date.
func (c *Core) DeleteCampaignViews(before time.Time) error {
	if _, err := c.q.DeleteCampaignViews.Exec(before); err != nil {
		c.log.Printf("error deleting campaign views: %s", err)
		return echo.NewHTTPError(http.StatusInternalServerError, c.i18n.Ts("public.errorProcessingRequest"))
	}

	return nil
}

// DeleteCampaignLinkClicks deletes campaign views older than a given date.
func (c *Core) DeleteCampaignLinkClicks(before time.Time) error {
	if _, err := c.q.DeleteCampaignLinkClicks.Exec(before); err != nil {
		c.log.Printf("error deleting campaign link clicks: %s", err)
		return echo.NewHTTPError(http.StatusInternalServerError, c.i18n.Ts("public.errorProcessingRequest"))
	}

	return nil
}
