package sqlstore

import (
	"strings"
	"time"

	"github.com/grafana/grafana/pkg/bus"
	"github.com/grafana/grafana/pkg/metrics"
	m "github.com/grafana/grafana/pkg/models"
	"github.com/grafana/grafana/pkg/services/search"
	"github.com/grafana/grafana/pkg/util"
)

func init() {
	bus.AddHandler("sql", SaveDashboard)
	bus.AddHandler("sql", GetDashboard)
	bus.AddHandler("sql", GetDashboards)
	bus.AddHandler("sql", DeleteDashboard)
	bus.AddHandler("sql", SearchDashboards)
	bus.AddHandler("sql", GetDashboardTags)
	bus.AddHandler("sql", GetDashboardSlugById)
	bus.AddHandler("sql", GetDashboardUIDById)
	bus.AddHandler("sql", GetDashboardsByPluginId)
	bus.AddHandler("sql", GetDashboardPermissionsForUser)
	bus.AddHandler("sql", GetDashboardsBySlug)
	bus.AddHandler("sql", ValidateDashboardBeforeSave)
	bus.AddHandler("sql", HasEditPermissionInFolders)
}

var generateNewUid func() string = util.GenerateShortUid

func SaveDashboard(cmd *m.SaveDashboardCommand) error {
	return inTransaction(func(sess *DBSession) error {
		return saveDashboard(sess, cmd)
	})
}

func saveDashboard(sess *DBSession, cmd *m.SaveDashboardCommand) error {
	dash := cmd.GetDashboardModel()

	userId := cmd.UserId

	if userId == 0 {
		userId = -1
	}

	if dash.Id > 0 {
		var existing m.Dashboard
		dashWithIdExists, err := sess.Where("id=? AND org_id=?", dash.Id, dash.OrgId).Get(&existing)
		if err != nil {
			return err
		}
		if !dashWithIdExists {
			return m.ErrDashboardNotFound
		}

		// check for is someone else has written in between
		if dash.Version != existing.Version {
			if cmd.Overwrite {
				dash.SetVersion(existing.Version)
			} else {
				return m.ErrDashboardVersionMismatch
			}
		}

		// do not allow plugin dashboard updates without overwrite flag
		if existing.PluginId != "" && !cmd.Overwrite {
			return m.UpdatePluginDashboardError{PluginId: existing.PluginId}
		}
	}

	if dash.Uid == "" {
		uid, err := generateNewDashboardUid(sess, dash.OrgId)
		if err != nil {
			return err
		}
		dash.SetUid(uid)
	}

	parentVersion := dash.Version
	var affectedRows int64
	var err error

	if dash.Id == 0 {
		dash.SetVersion(1)
		dash.Created = time.Now()
		dash.CreatedBy = userId
		dash.Updated = time.Now()
		dash.UpdatedBy = userId
		metrics.M_Api_Dashboard_Insert.Inc()
		affectedRows, err = sess.Insert(dash)
	} else {
		dash.SetVersion(dash.Version + 1)

		if !cmd.UpdatedAt.IsZero() {
			dash.Updated = cmd.UpdatedAt
		} else {
			dash.Updated = time.Now()
		}

		dash.UpdatedBy = userId

		affectedRows, err = sess.MustCols("folder_id").ID(dash.Id).Update(dash)
	}

	if err != nil {
		return err
	}

	if affectedRows == 0 {
		return m.ErrDashboardNotFound
	}

	dashVersion := &m.DashboardVersion{
		DashboardId:   dash.Id,
		ParentVersion: parentVersion,
		RestoredFrom:  cmd.RestoredFrom,
		Version:       dash.Version,
		Created:       time.Now(),
		CreatedBy:     dash.UpdatedBy,
		Message:       cmd.Message,
		Data:          dash.Data,
	}

	// insert version entry
	if affectedRows, err = sess.Insert(dashVersion); err != nil {
		return err
	} else if affectedRows == 0 {
		return m.ErrDashboardNotFound
	}

	// delete existing tags
	_, err = sess.Exec("DELETE FROM dashboard_tag WHERE dashboard_id=?", dash.Id)
	if err != nil {
		return err
	}

	// insert new tags
	tags := dash.GetTags()
	if len(tags) > 0 {
		for _, tag := range tags {
			if _, err := sess.Insert(&DashboardTag{DashboardId: dash.Id, Term: tag}); err != nil {
				return err
			}
		}
	}

	cmd.Result = dash

	return err
}

func generateNewDashboardUid(sess *DBSession, orgId int64) (string, error) {
	for i := 0; i < 3; i++ {
		uid := generateNewUid()

		exists, err := sess.Where("org_id=? AND uid=?", orgId, uid).Get(&m.Dashboard{})
		if err != nil {
			return "", err
		}

		if !exists {
			return uid, nil
		}
	}

	return "", m.ErrDashboardFailedGenerateUniqueUid
}

func GetDashboard(query *m.GetDashboardQuery) error {
	dashboard := m.Dashboard{Slug: query.Slug, OrgId: query.OrgId, Id: query.Id, Uid: query.Uid}
	has, err := x.Get(&dashboard)

	if err != nil {
		return err
	} else if !has {
		return m.ErrDashboardNotFound
	}

	dashboard.SetId(dashboard.Id)
	dashboard.SetUid(dashboard.Uid)
	query.Result = &dashboard
	return nil
}

type DashboardSearchProjection struct {
	Id          int64
	Uid         string
	Title       string
	Slug        string
	Term        string
	IsFolder    bool
	FolderId    int64
	FolderUid   string
	FolderSlug  string
	FolderTitle string
}

func findDashboards(query *search.FindPersistedDashboardsQuery) ([]DashboardSearchProjection, error) {
	limit := query.Limit
	if limit == 0 {
		limit = 1000
	}

	sb := NewSearchBuilder(query.SignedInUser, limit, query.Permission).
		WithTags(query.Tags).
		WithDashboardIdsIn(query.DashboardIds)

	if query.IsStarred {
		sb.IsStarred()
	}

	if len(query.Title) > 0 {
		sb.WithTitle(query.Title)
	}

	if len(query.Type) > 0 {
		sb.WithType(query.Type)
	}

	if len(query.FolderIds) > 0 {
		sb.WithFolderIds(query.FolderIds)
	}

	var res []DashboardSearchProjection

	sql, params := sb.ToSql()
	err := x.SQL(sql, params...).Find(&res)
	if err != nil {
		return nil, err
	}

	return res, nil
}

func SearchDashboards(query *search.FindPersistedDashboardsQuery) error {
	res, err := findDashboards(query)
	if err != nil {
		return err
	}

	makeQueryResult(query, res)

	return nil
}

func getHitType(item DashboardSearchProjection) search.HitType {
	var hitType search.HitType
	if item.IsFolder {
		hitType = search.DashHitFolder
	} else {
		hitType = search.DashHitDB
	}

	return hitType
}

func makeQueryResult(query *search.FindPersistedDashboardsQuery, res []DashboardSearchProjection) {
	query.Result = make([]*search.Hit, 0)
	hits := make(map[int64]*search.Hit)

	for _, item := range res {
		hit, exists := hits[item.Id]
		if !exists {
			hit = &search.Hit{
				Id:          item.Id,
				Uid:         item.Uid,
				Title:       item.Title,
				Uri:         "db/" + item.Slug,
				Url:         m.GetDashboardFolderUrl(item.IsFolder, item.Uid, item.Slug),
				Type:        getHitType(item),
				FolderId:    item.FolderId,
				FolderUid:   item.FolderUid,
				FolderTitle: item.FolderTitle,
				Tags:        []string{},
			}

			if item.FolderId > 0 {
				hit.FolderUrl = m.GetFolderUrl(item.FolderUid, item.FolderSlug)
			}

			query.Result = append(query.Result, hit)
			hits[item.Id] = hit
		}
		if len(item.Term) > 0 {
			hit.Tags = append(hit.Tags, item.Term)
		}
	}
}

func GetDashboardTags(query *m.GetDashboardTagsQuery) error {
	sql := `SELECT
					  COUNT(*) as count,
						term
					FROM dashboard
					INNER JOIN dashboard_tag on dashboard_tag.dashboard_id = dashboard.id
					WHERE dashboard.org_id=?
					GROUP BY term
					ORDER BY term`

	query.Result = make([]*m.DashboardTagCloudItem, 0)
	sess := x.SQL(sql, query.OrgId)
	err := sess.Find(&query.Result)
	return err
}

func DeleteDashboard(cmd *m.DeleteDashboardCommand) error {
	return inTransaction(func(sess *DBSession) error {
		dashboard := m.Dashboard{Id: cmd.Id, OrgId: cmd.OrgId}
		has, err := sess.Get(&dashboard)
		if err != nil {
			return err
		} else if !has {
			return m.ErrDashboardNotFound
		}

		deletes := []string{
			"DELETE FROM dashboard_tag WHERE dashboard_id = ? ",
			"DELETE FROM star WHERE dashboard_id = ? ",
			"DELETE FROM dashboard WHERE id = ?",
			"DELETE FROM playlist_item WHERE type = 'dashboard_by_id' AND value = ?",
			"DELETE FROM dashboard_version WHERE dashboard_id = ?",
			"DELETE FROM dashboard WHERE folder_id = ?",
			"DELETE FROM annotation WHERE dashboard_id = ?",
			"DELETE FROM dashboard_provisioning WHERE dashboard_id = ?",
		}

		for _, sql := range deletes {
			_, err := sess.Exec(sql, dashboard.Id)
			if err != nil {
				return err
			}
		}

		if err := deleteAlertDefinition(dashboard.Id, sess); err != nil {
			return nil
		}

		return nil
	})
}

func GetDashboards(query *m.GetDashboardsQuery) error {
	if len(query.DashboardIds) == 0 {
		return m.ErrCommandValidationFailed
	}

	var dashboards = make([]*m.Dashboard, 0)

	err := x.In("id", query.DashboardIds).Find(&dashboards)
	query.Result = dashboards
	return err
}

// GetDashboardPermissionsForUser returns the maximum permission the specified user has for a dashboard(s)
// The function takes in a list of dashboard ids and the user id and role
func GetDashboardPermissionsForUser(query *m.GetDashboardPermissionsForUserQuery) error {
	if len(query.DashboardIds) == 0 {
		return m.ErrCommandValidationFailed
	}

	if query.OrgRole == m.ROLE_ADMIN {
		var permissions = make([]*m.DashboardPermissionForUser, 0)
		for _, d := range query.DashboardIds {
			permissions = append(permissions, &m.DashboardPermissionForUser{
				DashboardId:    d,
				Permission:     m.PERMISSION_ADMIN,
				PermissionName: m.PERMISSION_ADMIN.String(),
			})
		}
		query.Result = permissions

		return nil
	}

	params := make([]interface{}, 0)

	// check dashboards that have ACLs via user id, team id or role
	sql := `SELECT d.id AS dashboard_id, MAX(COALESCE(da.permission, pt.permission)) AS permission
	FROM dashboard AS d
		LEFT JOIN dashboard_acl as da on d.folder_id = da.dashboard_id or d.id = da.dashboard_id
		LEFT JOIN team_member as ugm on ugm.team_id =  da.team_id
		LEFT JOIN org_user ou ON ou.role = da.role AND ou.user_id = ?
	`
	params = append(params, query.UserId)

	//check the user's role for dashboards that do not have hasAcl set
	sql += `LEFT JOIN org_user ouRole ON ouRole.user_id = ? AND ouRole.org_id = ?`
	params = append(params, query.UserId)
	params = append(params, query.OrgId)

	sql += `
		LEFT JOIN (SELECT 1 AS permission, 'Viewer' AS role
			UNION SELECT 2 AS permission, 'Editor' AS role
			UNION SELECT 4 AS permission, 'Admin' AS role) pt ON ouRole.role = pt.role
	WHERE
	d.Id IN (?` + strings.Repeat(",?", len(query.DashboardIds)-1) + `) `
	for _, id := range query.DashboardIds {
		params = append(params, id)
	}

	sql += ` AND
	d.org_id = ? AND
	  (
		(d.has_acl = ?  AND (da.user_id = ? OR ugm.user_id = ? OR ou.id IS NOT NULL))
		OR (d.has_acl = ? AND ouRole.id IS NOT NULL)
	)
	group by d.id
	order by d.id asc`
	params = append(params, query.OrgId)
	params = append(params, dialect.BooleanStr(true))
	params = append(params, query.UserId)
	params = append(params, query.UserId)
	params = append(params, dialect.BooleanStr(false))

	err := x.SQL(sql, params...).Find(&query.Result)

	for _, p := range query.Result {
		p.PermissionName = p.Permission.String()
	}

	return err
}

func GetDashboardsByPluginId(query *m.GetDashboardsByPluginIdQuery) error {
	var dashboards = make([]*m.Dashboard, 0)
	whereExpr := "org_id=? AND plugin_id=? AND is_folder=" + dialect.BooleanStr(false)

	err := x.Where(whereExpr, query.OrgId, query.PluginId).Find(&dashboards)
	query.Result = dashboards
	return err
}

type DashboardSlugDTO struct {
	Slug string
}

func GetDashboardSlugById(query *m.GetDashboardSlugByIdQuery) error {
	var rawSql = `SELECT slug from dashboard WHERE Id=?`
	var slug = DashboardSlugDTO{}

	exists, err := x.SQL(rawSql, query.Id).Get(&slug)

	if err != nil {
		return err
	} else if !exists {
		return m.ErrDashboardNotFound
	}

	query.Result = slug.Slug
	return nil
}

func GetDashboardsBySlug(query *m.GetDashboardsBySlugQuery) error {
	var dashboards []*m.Dashboard

	if err := x.Where("org_id=? AND slug=?", query.OrgId, query.Slug).Find(&dashboards); err != nil {
		return err
	}

	query.Result = dashboards
	return nil
}

func GetDashboardUIDById(query *m.GetDashboardRefByIdQuery) error {
	var rawSql = `SELECT uid, slug from dashboard WHERE Id=?`

	us := &m.DashboardRef{}

	exists, err := x.SQL(rawSql, query.Id).Get(us)

	if err != nil {
		return err
	} else if !exists {
		return m.ErrDashboardNotFound
	}

	query.Result = us
	return nil
}

func getExistingDashboardByIdOrUidForUpdate(sess *DBSession, cmd *m.ValidateDashboardBeforeSaveCommand) (err error) {
	dash := cmd.Dashboard

	dashWithIdExists := false
	var existingById m.Dashboard

	if dash.Id > 0 {
		dashWithIdExists, err = sess.Where("id=? AND org_id=?", dash.Id, dash.OrgId).Get(&existingById)
		if err != nil {
			return err
		}

		if !dashWithIdExists {
			return m.ErrDashboardNotFound
		}

		if dash.Uid == "" {
			dash.SetUid(existingById.Uid)
		}
	}

	dashWithUidExists := false
	var existingByUid m.Dashboard

	if dash.Uid != "" {
		dashWithUidExists, err = sess.Where("org_id=? AND uid=?", dash.OrgId, dash.Uid).Get(&existingByUid)
		if err != nil {
			return err
		}
	}

	if dash.FolderId > 0 {
		var existingFolder m.Dashboard
		folderExists, folderErr := sess.Where("org_id=? AND id=? AND is_folder=?", dash.OrgId, dash.FolderId, dialect.BooleanStr(true)).Get(&existingFolder)
		if folderErr != nil {
			return folderErr
		}

		if !folderExists {
			return m.ErrDashboardFolderNotFound
		}
	}

	if !dashWithIdExists && !dashWithUidExists {
		return nil
	}

	if dashWithIdExists && dashWithUidExists && existingById.Id != existingByUid.Id {
		return m.ErrDashboardWithSameUIDExists
	}

	existing := existingById

	if !dashWithIdExists && dashWithUidExists {
		dash.SetId(existingByUid.Id)
		dash.SetUid(existingByUid.Uid)
		existing = existingByUid

		if !dash.IsFolder {
			cmd.Result.IsParentFolderChanged = true
		}
	}

	if (existing.IsFolder && !dash.IsFolder) ||
		(!existing.IsFolder && dash.IsFolder) {
		return m.ErrDashboardTypeMismatch
	}

	if !dash.IsFolder && dash.FolderId != existing.FolderId {
		cmd.Result.IsParentFolderChanged = true
	}

	// check for is someone else has written in between
	if dash.Version != existing.Version {
		if cmd.Overwrite {
			dash.SetVersion(existing.Version)
		} else {
			return m.ErrDashboardVersionMismatch
		}
	}

	// do not allow plugin dashboard updates without overwrite flag
	if existing.PluginId != "" && !cmd.Overwrite {
		return m.UpdatePluginDashboardError{PluginId: existing.PluginId}
	}

	return nil
}

func getExistingDashboardByTitleAndFolder(sess *DBSession, cmd *m.ValidateDashboardBeforeSaveCommand) error {
	dash := cmd.Dashboard
	var existing m.Dashboard

	exists, err := sess.Where("org_id=? AND slug=? AND (is_folder=? OR folder_id=?)", dash.OrgId, dash.Slug, dialect.BooleanStr(true), dash.FolderId).Get(&existing)
	if err != nil {
		return err
	}

	if exists && dash.Id != existing.Id {
		if existing.IsFolder && !dash.IsFolder {
			return m.ErrDashboardWithSameNameAsFolder
		}

		if !existing.IsFolder && dash.IsFolder {
			return m.ErrDashboardFolderWithSameNameAsDashboard
		}

		if !dash.IsFolder && (dash.FolderId != existing.FolderId || dash.Id == 0) {
			cmd.Result.IsParentFolderChanged = true
		}

		if cmd.Overwrite {
			dash.SetId(existing.Id)
			dash.SetUid(existing.Uid)
			dash.SetVersion(existing.Version)
		} else {
			return m.ErrDashboardWithSameNameInFolderExists
		}
	}

	return nil
}

func ValidateDashboardBeforeSave(cmd *m.ValidateDashboardBeforeSaveCommand) (err error) {
	cmd.Result = &m.ValidateDashboardBeforeSaveResult{}
	return inTransaction(func(sess *DBSession) error {
		if err = getExistingDashboardByIdOrUidForUpdate(sess, cmd); err != nil {
			return err
		}

		if err = getExistingDashboardByTitleAndFolder(sess, cmd); err != nil {
			return err
		}

		return nil
	})
}

func HasEditPermissionInFolders(query *m.HasEditPermissionInFoldersQuery) error {
	if query.SignedInUser.HasRole(m.ROLE_EDITOR) {
		query.Result = true
		return nil
	}

	builder := &SqlBuilder{}
	builder.Write("SELECT COUNT(dashboard.id) AS count FROM dashboard WHERE dashboard.org_id = ? AND dashboard.is_folder = ?", query.SignedInUser.OrgId, dialect.BooleanStr(true))
	builder.writeDashboardPermissionFilter(query.SignedInUser, m.PERMISSION_EDIT)

	type folderCount struct {
		Count int64
	}

	resp := make([]*folderCount, 0)
	if err := x.SQL(builder.GetSqlString(), builder.params...).Find(&resp); err != nil {
		return err
	}

	query.Result = len(resp) > 0 && resp[0].Count > 0

	return nil
}