package models

import (
	"errors"
	"time"

	"github.com/jinzhu/gorm"
)

// Campaign is a struct representing a created campaign
type Campaign struct {
	Id            int64     `json:"id"`
	UserId        int64     `json:"-"`
	Name          string    `json:"name" sql:"not null"`
	CreatedDate   time.Time `json:"created_date"`
	LaunchDate    time.Time `json:"launch_date"`
	CompletedDate time.Time `json:"completed_date"`
	TemplateId    int64     `json:"-"`
	Template      Template  `json:"template"`
	PageId        int64     `json:"-"`
	Page          Page      `json:"page"`
	Status        string    `json:"status"`
	Results       []Result  `json:"results,omitempty"`
	Groups        []Group   `json:"groups,omitempty"`
	Events        []Event   `json:"timeline,omitemtpy"`
	SMTPId        int64     `json:"-"`
	SMTP          SMTP      `json:"smtp"`
	URL           string    `json:"url"`
}

// CampaignResults is a struct representing the results from a campaign
type CampaignResults struct {
	Id      int64    `json:"id"`
	Name    string   `json:"name"`
	Status  string   `json:"status"`
	Results []Result `json:"results, omitempty"`
	Events  []Event  `json:"timeline,omitempty"`
}

// CampaignsSummary is a struct representing the overview of campaigns
type CampaignSummaries struct {
	Total     int64             `json:"total"`
	Campaigns []CampaignSummary `json:"campaigns"`
}

// CampaignSummary is a struct representing the overview of a single camaign
type CampaignSummary struct {
	Id            int64         `json:"id"`
	CreatedDate   time.Time     `json:"created_date"`
	LaunchDate    time.Time     `json:"launch_date"`
	CompletedDate time.Time     `json:"completed_date"`
	Status        string        `json:"status"`
	Name          string        `json:"name"`
	Stats         CampaignStats `json:"stats"`
}

// CampaignStats is a struct representing the statistics for a single campaign
type CampaignStats struct {
	Total         int64 `json:"total"`
	EmailsSent    int64 `json:"sent"`
	OpenedEmail   int64 `json:"opened"`
	ClickedLink   int64 `json:"clicked"`
	SubmittedData int64 `json:"submitted_data"`
	Error         int64 `json:"error"`
}

// ErrCampaignNameNotSpecified indicates there was no template given by the user
var ErrCampaignNameNotSpecified = errors.New("Campaign name not specified")

// ErrGroupNotSpecified indicates there was no template given by the user
var ErrGroupNotSpecified = errors.New("No groups specified")

// ErrTemplateNotSpecified indicates there was no template given by the user
var ErrTemplateNotSpecified = errors.New("No email template specified")

// ErrPageNotSpecified indicates a landing page was not provided for the campaign
var ErrPageNotSpecified = errors.New("No landing page specified")

// ErrSMTPNotSpecified indicates a sending profile was not provided for the campaign
var ErrSMTPNotSpecified = errors.New("No sending profile specified")

// ErrTemplateNotFound indicates the template specified does not exist in the database
var ErrTemplateNotFound = errors.New("Template not found")

// ErrGroupnNotFound indicates a group specified by the user does not exist in the database
var ErrGroupNotFound = errors.New("Group not found")

// ErrPageNotFound indicates a page specified by the user does not exist in the database
var ErrPageNotFound = errors.New("Page not found")

// ErrSMTPNotFound indicates a sending profile specified by the user does not exist in the database
var ErrSMTPNotFound = errors.New("Sending profile not found")

// Validate checks to make sure there are no invalid fields in a submitted campaign
func (c *Campaign) Validate() error {
	switch {
	case c.Name == "":
		return ErrCampaignNameNotSpecified
	case len(c.Groups) == 0:
		return ErrGroupNotSpecified
	case c.Template.Name == "":
		return ErrTemplateNotSpecified
	case c.Page.Name == "":
		return ErrPageNotSpecified
	case c.SMTP.Name == "":
		return ErrSMTPNotSpecified
	}
	return nil
}

// SendTestEmailRequest is the structure of a request
// to send a test email to test an SMTP connection
type SendTestEmailRequest struct {
	Template    Template `json:"template"`
	Page        Page     `json:"page"`
	SMTP        SMTP     `json:"smtp"`
	URL         string   `json:"url"`
	Tracker     string   `json:"tracker"`
	TrackingURL string   `json:"tracking_url"`
	From        string   `json:"from"`
	Target
}

// Validate ensures the SendTestEmailRequest structure
// is valid.
func (s *SendTestEmailRequest) Validate() error {
	switch {
	case s.Email == "":
		return ErrEmailNotSpecified
	}
	return nil
}

// UpdateStatus changes the campaign status appropriately
func (c *Campaign) UpdateStatus(s string) error {
	// This could be made simpler, but I think there's a bug in gorm
	return db.Table("campaigns").Where("id=?", c.Id).Update("status", s).Error
}

// AddEvent creates a new campaign event in the database
func (c *Campaign) AddEvent(e Event) error {
	e.CampaignId = c.Id
	e.Time = time.Now().UTC()
	return db.Debug().Save(&e).Error
}

// getDetails retrieves the related attributes of the campaign
// from the database. If the Events and the Results are not available,
// an error is returned. Otherwise, the attribute name is set to [Deleted],
// indicating the user deleted the attribute (template, smtp, etc.)
func (c *Campaign) getDetails() error {
	err = db.Model(c).Related(&c.Results).Error
	if err != nil {
		Logger.Printf("%s: results not found for campaign\n", err)
		return err
	}
	err = db.Model(c).Related(&c.Events).Error
	if err != nil {
		Logger.Printf("%s: events not found for campaign\n", err)
		return err
	}
	err = db.Table("templates").Where("id=?", c.TemplateId).Find(&c.Template).Error
	if err != nil {
		if err != gorm.ErrRecordNotFound {
			return err
		}
		c.Template = Template{Name: "[Deleted]"}
		Logger.Printf("%s: template not found for campaign\n", err)
	}
	err = db.Where("template_id=?", c.Template.Id).Find(&c.Template.Attachments).Error
	if err != nil && err != gorm.ErrRecordNotFound {
		Logger.Println(err)
		return err
	}
	err = db.Table("pages").Where("id=?", c.PageId).Find(&c.Page).Error
	if err != nil {
		if err != gorm.ErrRecordNotFound {
			return err
		}
		c.Page = Page{Name: "[Deleted]"}
		Logger.Printf("%s: page not found for campaign\n", err)
	}
	err = db.Table("smtp").Where("id=?", c.SMTPId).Find(&c.SMTP).Error
	if err != nil {
		// Check if the SMTP was deleted
		if err != gorm.ErrRecordNotFound {
			return err
		}
		c.SMTP = SMTP{Name: "[Deleted]"}
		Logger.Printf("%s: sending profile not found for campaign\n", err)
	}
	err = db.Where("smtp_id=?", c.SMTP.Id).Find(&c.SMTP.Headers).Error
	if err != nil && err != gorm.ErrRecordNotFound {
		Logger.Println(err)
		return err
	}
	return nil
}

// getCampaignStats returns a CampaignStats object for the campaign with the given campaign ID.
// It also backfills numbers as appropriate with a running total, so that the values are aggregated.
func getCampaignStats(cid int64) (CampaignStats, error) {
	s := CampaignStats{}
	query := db.Table("results").Where("campaign_id = ?", cid)
	err := query.Count(&s.Total).Error
	if err != nil {
		return s, err
	}
	query.Where("status=?", EVENT_DATA_SUBMIT).Count(&s.SubmittedData)
	if err != nil {
		return s, err
	}
	query.Where("status=?", EVENT_CLICKED).Count(&s.ClickedLink)
	if err != nil {
		return s, err
	}
	// Every submitted data event implies they clicked the link
	s.ClickedLink += s.SubmittedData
	err = query.Where("status=?", EVENT_OPENED).Count(&s.OpenedEmail).Error
	if err != nil {
		return s, err
	}
	// Every clicked link event implies they opened the email
	s.OpenedEmail += s.ClickedLink
	err = query.Where("status=?", EVENT_SENT).Count(&s.EmailsSent).Error
	if err != nil {
		return s, err
	}
	// Every opened email event implies the email was sent
	s.EmailsSent += s.OpenedEmail
	err = query.Where("status=?", ERROR).Count(&s.Error).Error
	return s, err
}

// Event contains the fields for an event
// that occurs during the campaign
type Event struct {
	Id         int64     `json:"-"`
	CampaignId int64     `json:"-"`
	Email      string    `json:"email"`
	Time       time.Time `json:"time"`
	Message    string    `json:"message"`
	Details    string    `json:"details"`
}

// GetCampaigns returns the campaigns owned by the given user.
func GetCampaigns(uid int64) ([]Campaign, error) {
	cs := []Campaign{}
	err := db.Model(&User{Id: uid}).Related(&cs).Error
	if err != nil {
		Logger.Println(err)
	}
	for i, _ := range cs {
		err = cs[i].getDetails()
		if err != nil {
			Logger.Println(err)
		}
	}
	return cs, err
}

// GetCampaignSummaries gets the summary objects for all the campaigns
// owned by the current user
func GetCampaignSummaries(uid int64) (CampaignSummaries, error) {
	overview := CampaignSummaries{}
	cs := []CampaignSummary{}
	// Get the basic campaign information
	query := db.Table("campaigns").Where("user_id = ?", uid)
	query = query.Select("id, name, created_date, launch_date, completed_date, status")
	err := query.Scan(&cs).Error
	if err != nil {
		Logger.Println(err)
		return overview, err
	}
	for i := range cs {
		s, err := getCampaignStats(cs[i].Id)
		if err != nil {
			Logger.Println(err)
			return overview, err
		}
		cs[i].Stats = s
		Logger.Println(cs[i].CreatedDate.String())
	}
	overview.Total = int64(len(cs))
	overview.Campaigns = cs
	return overview, nil
}

// GetCampaignSummary gets the summary object for a campaign specified by the campaign ID
func GetCampaignSummary(id int64, uid int64) (CampaignSummary, error) {
	cs := CampaignSummary{}
	query := db.Table("campaigns").Where("user_id = ? AND id = ?", uid, id)
	query = query.Select("id, name, created_date, launch_date, completed_date, status")
	err := query.Scan(&cs).Error
	if err != nil {
		Logger.Println(err)
		return cs, err
	}
	s, err := getCampaignStats(cs.Id)
	if err != nil {
		Logger.Println(err)
		return cs, err
	}
	cs.Stats = s
	return cs, nil
}

// GetCampaign returns the campaign, if it exists, specified by the given id and user_id.
func GetCampaign(id int64, uid int64) (Campaign, error) {
	c := Campaign{}
	err := db.Where("id = ?", id).Where("user_id = ?", uid).Find(&c).Error
	if err != nil {
		Logger.Printf("%s: campaign not found\n", err)
		return c, err
	}
	err = c.getDetails()
	return c, err
}

func GetCampaignResults(id int64, uid int64) (CampaignResults, error) {
	cr := CampaignResults{}
	err := db.Table("campaigns").Where("id=? and user_id=?", id, uid).Find(&cr).Error
	if err != nil {
		Logger.Printf("%s: campaign not found\n", err)
		return cr, err
	}
	err = db.Table("results").Where("campaign_id=? and user_id=?", cr.Id, uid).Find(&cr.Results).Error
	if err != nil {
		Logger.Printf("%s: results not found for campaign\n", err)
		return cr, err
	}
	err = db.Table("events").Where("campaign_id=?", cr.Id).Find(&cr.Events).Error
	if err != nil {
		Logger.Printf("%s: events not found for campaign\n", err)
		return cr, err
	}
	return cr, err
}

// GetQueuedCampaigns returns the campaigns that are queued up for this given minute
func GetQueuedCampaigns(t time.Time) ([]Campaign, error) {
	cs := []Campaign{}
	err := db.Where("launch_date <= ?", t).
		Where("status = ?", CAMPAIGN_QUEUED).Find(&cs).Error
	if err != nil {
		Logger.Println(err)
	}
	Logger.Printf("Found %d Campaigns to run\n", len(cs))
	for i, _ := range cs {
		err = cs[i].getDetails()
		if err != nil {
			Logger.Println(err)
		}
	}
	return cs, err
}

// PostCampaign inserts a campaign and all associated records into the database.
func PostCampaign(c *Campaign, uid int64) error {
	if err := c.Validate(); err != nil {
		return err
	}
	// Fill in the details
	c.UserId = uid
	c.CreatedDate = time.Now().UTC()
	c.CompletedDate = time.Time{}
	c.Status = CAMPAIGN_CREATED
	if c.LaunchDate.IsZero() {
		c.LaunchDate = time.Now().UTC()
	} else {
		c.LaunchDate = c.LaunchDate.UTC()
	}
	// Check to make sure all the groups already exist
	for i, g := range c.Groups {
		c.Groups[i], err = GetGroupByName(g.Name, uid)
		if err == gorm.ErrRecordNotFound {
			Logger.Printf("Error - Group %s does not exist", g.Name)
			return ErrGroupNotFound
		} else if err != nil {
			Logger.Println(err)
			return err
		}
	}
	// Check to make sure the template exists
	t, err := GetTemplateByName(c.Template.Name, uid)
	if err == gorm.ErrRecordNotFound {
		Logger.Printf("Error - Template %s does not exist", t.Name)
		return ErrTemplateNotFound
	} else if err != nil {
		Logger.Println(err)
		return err
	}
	c.Template = t
	c.TemplateId = t.Id
	// Check to make sure the page exists
	p, err := GetPageByName(c.Page.Name, uid)
	if err == gorm.ErrRecordNotFound {
		Logger.Printf("Error - Page %s does not exist", p.Name)
		return ErrPageNotFound
	} else if err != nil {
		Logger.Println(err)
		return err
	}
	c.Page = p
	c.PageId = p.Id
	// Check to make sure the sending profile exists
	s, err := GetSMTPByName(c.SMTP.Name, uid)
	if err == gorm.ErrRecordNotFound {
		Logger.Printf("Error - Sending profile %s does not exist", s.Name)
		return ErrPageNotFound
	} else if err != nil {
		Logger.Println(err)
		return err
	}
	c.SMTP = s
	c.SMTPId = s.Id
	// Insert into the DB
	err = db.Save(c).Error
	if err != nil {
		Logger.Println(err)
		return err
	}
	err = c.AddEvent(Event{Message: "Campaign Created"})
	if err != nil {
		Logger.Println(err)
	}
	// Insert all the results
	for _, g := range c.Groups {
		// Insert a result for each target in the group
		for _, t := range g.Targets {
			r := &Result{Email: t.Email, Position: t.Position, Status: STATUS_SENDING, CampaignId: c.Id, UserId: c.UserId, FirstName: t.FirstName, LastName: t.LastName}
			err = r.GenerateId()
			if err != nil {
				Logger.Println(err)
				continue
			}
			err = db.Save(r).Error
			if err != nil {
				Logger.Printf("Error adding result record for target %s\n", t.Email)
				Logger.Println(err)
			}
			c.Results = append(c.Results, *r)
		}
	}
	c.Status = CAMPAIGN_QUEUED
	err = db.Save(c).Error
	return err
}

//DeleteCampaign deletes the specified campaign
func DeleteCampaign(id int64) error {
	Logger.Printf("Deleting campaign %d\n", id)
	// Delete all the campaign results
	err := db.Where("campaign_id=?", id).Delete(&Result{}).Error
	if err != nil {
		Logger.Println(err)
		return err
	}
	err = db.Where("campaign_id=?", id).Delete(&Event{}).Error
	if err != nil {
		Logger.Println(err)
		return err
	}
	// Delete the campaign
	err = db.Delete(&Campaign{Id: id}).Error
	if err != nil {
		Logger.Println(err)
	}
	return err
}

// CompleteCampaign effectively "ends" a campaign.
// Any future emails clicked will return a simple "404" page.
func CompleteCampaign(id int64, uid int64) error {
	Logger.Printf("Marking campaign %d as complete\n", id)
	c, err := GetCampaign(id, uid)
	if err != nil {
		return err
	}
	// Don't overwrite original completed time
	if c.Status == CAMPAIGN_COMPLETE {
		return nil
	}
	// Mark the campaign as complete
	c.CompletedDate = time.Now().UTC()
	c.Status = CAMPAIGN_COMPLETE
	err = db.Where("id=? and user_id=?", id, uid).Save(&c).Error
	if err != nil {
		Logger.Println(err)
	}
	return err
}