package sqlstore

import (
	"database/sql"
	"encoding/json"
	"errors"
	"fmt"
	"time"

	"github.com/mattermost/focalboard/server/model"
	"github.com/mattermost/focalboard/server/utils"

	"github.com/mattermost/mattermost-server/v6/shared/mlog"

	sq "github.com/Masterminds/squirrel"
)

var (
	errUnsupportedDatabaseError = errors.New("method is unsupported on current database. Supported databases are - MySQL and PostgreSQL")
)

func (s *SQLStore) UpsertWorkspaceSignupToken(workspace model.Workspace) error {
	now := time.Now().Unix()

	query := s.getQueryBuilder().
		Insert(s.tablePrefix+"workspaces").
		Columns(
			"id",
			"signup_token",
			"modified_by",
			"update_at",
		).
		Values(
			workspace.ID,
			workspace.SignupToken,
			workspace.ModifiedBy,
			now,
		)
	if s.dbType == mysqlDBType {
		query = query.Suffix("ON DUPLICATE KEY UPDATE signup_token = ?, modified_by = ?, update_at = ?",
			workspace.SignupToken, workspace.ModifiedBy, now)
	} else {
		query = query.Suffix(
			`ON CONFLICT (id)
			 DO UPDATE SET signup_token = EXCLUDED.signup_token, modified_by = EXCLUDED.modified_by, update_at = EXCLUDED.update_at`,
		)
	}

	_, err := query.Exec()
	return err
}

func (s *SQLStore) UpsertWorkspaceSettings(workspace model.Workspace) error {
	now := time.Now().Unix()
	signupToken := utils.CreateGUID()

	settingsJSON, err := json.Marshal(workspace.Settings)
	if err != nil {
		return err
	}

	query := s.getQueryBuilder().
		Insert(s.tablePrefix+"workspaces").
		Columns(
			"id",
			"signup_token",
			"settings",
			"modified_by",
			"update_at",
		).
		Values(
			workspace.ID,
			signupToken,
			settingsJSON,
			workspace.ModifiedBy,
			now,
		)
	if s.dbType == mysqlDBType {
		query = query.Suffix("ON DUPLICATE KEY UPDATE settings = ?, modified_by = ?, update_at = ?", settingsJSON, workspace.ModifiedBy, now)
	} else {
		query = query.Suffix(
			`ON CONFLICT (id)
			 DO UPDATE SET settings = EXCLUDED.settings, modified_by = EXCLUDED.modified_by, update_at = EXCLUDED.update_at`,
		)
	}

	_, err = query.Exec()
	return err
}

func (s *SQLStore) GetWorkspace(id string) (*model.Workspace, error) {
	var settingsJSON string

	query := s.getQueryBuilder().
		Select(
			"id",
			"signup_token",
			"COALESCE(settings, '{}')",
			"modified_by",
			"update_at",
		).
		From(s.tablePrefix + "workspaces").
		Where(sq.Eq{"id": id})
	row := query.QueryRow()
	workspace := model.Workspace{}

	err := row.Scan(
		&workspace.ID,
		&workspace.SignupToken,
		&settingsJSON,
		&workspace.ModifiedBy,
		&workspace.UpdateAt,
	)
	if err != nil {
		return nil, err
	}

	err = json.Unmarshal([]byte(settingsJSON), &workspace.Settings)
	if err != nil {
		s.logger.Error(`ERROR GetWorkspace settings json.Unmarshal`, mlog.Err(err))
		return nil, err
	}

	return &workspace, nil
}

func (s *SQLStore) HasWorkspaceAccess(userID string, workspaceID string) (bool, error) {
	return true, nil
}

func (s *SQLStore) GetWorkspaceCount() (int64, error) {
	query := s.getQueryBuilder().
		Select(
			"COUNT(*) AS count",
		).
		From(s.tablePrefix + "workspaces")

	rows, err := query.Query()
	if err != nil {
		s.logger.Error("ERROR GetWorkspaceCount", mlog.Err(err))
		return 0, err
	}
	defer s.CloseRows(rows)

	var count int64

	rows.Next()
	err = rows.Scan(&count)
	if err != nil {
		s.logger.Error("Failed to fetch workspace count", mlog.Err(err))
		return 0, err
	}
	return count, nil
}

func (s *SQLStore) GetUserWorkspaces(userID string) ([]model.UserWorkspace, error) {
	var query sq.SelectBuilder

	var nonTemplateFilter string

	switch s.dbType {
	case mysqlDBType:
		nonTemplateFilter = "focalboard_blocks.fields LIKE %\"isTemplate\":false%"
	case postgresDBType:
		nonTemplateFilter = "focalboard_blocks.fields ->> 'isTemplate' = 'false'"
	default:
		return nil, fmt.Errorf("GetUserWorkspaces - %w", errUnsupportedDatabaseError)
	}

	query = s.getQueryBuilder().
		Select("Channels.ID", "Channels.DisplayName", "COUNT(focalboard_blocks.id)").
		From("ChannelMembers").
		// select channels without a corresponding workspace
		LeftJoin(
			"focalboard_blocks ON focalboard_blocks.workspace_id = ChannelMembers.ChannelId AND "+
				"focalboard_blocks.type = 'board' AND "+
				nonTemplateFilter,
		).
		Join("Channels ON ChannelMembers.ChannelId = Channels.Id").
		Where(sq.Eq{"ChannelMembers.UserId": userID}).
		GroupBy("Channels.Id", "Channels.DisplayName")

	rows, err := query.Query()
	if err != nil {
		s.logger.Error("ERROR GetUserWorkspaces", mlog.Err(err))
		return nil, err
	}

	defer s.CloseRows(rows)
	return s.userWorkspacesFromRows(rows)
}

func (s *SQLStore) userWorkspacesFromRows(rows *sql.Rows) ([]model.UserWorkspace, error) {
	userWorkspaces := []model.UserWorkspace{}

	for rows.Next() {
		var userWorkspace model.UserWorkspace

		err := rows.Scan(
			&userWorkspace.ID,
			&userWorkspace.Title,
			&userWorkspace.BoardCount,
		)

		if err != nil {
			s.logger.Error("ERROR userWorkspacesFromRows", mlog.Err(err))
			return nil, err
		}

		userWorkspaces = append(userWorkspaces, userWorkspace)
	}

	return userWorkspaces, nil
}