//go:build mysql
// +build mysql

package mysql

import (
	"fmt"
	"regexp"

	t "github.com/tinode/chat/server/store/types"
)

var (
	tenantTopicsTableRE              = regexp.MustCompile(`\bim_topics\b`)
	tenantGroupMembersTableRE        = regexp.MustCompile(`\bim_group_members\b`)
	tenantSubscriptionsTableRE       = regexp.MustCompile(`\bim_subscriptions\b`)
	tenantSystemNotificationsTableRE = regexp.MustCompile(`\bim_system_notifications\b`)
)

func tenantShardSQL(tenantID t.TenantID, query string) string {
	query = tenantTopicsTableRE.ReplaceAllString(query, tenantTopicsTable(tenantID))
	query = tenantGroupMembersTableRE.ReplaceAllString(query, tenantGroupMembersTable(tenantID))
	query = tenantSubscriptionsTableRE.ReplaceAllString(query, tenantSubscriptionsTable(tenantID))
	return tenantSystemNotificationsTableRE.ReplaceAllString(query, tenantSystemNotificationsTable(tenantID))
}

func tenantTablePrefix(tenantID t.TenantID) string {
	return fmt.Sprintf("im_%03d_", tenantID)
}

func tenantFriendshipsTable(tenantID t.TenantID) string {
	return tenantTablePrefix(tenantID) + "friendships"
}

func tenantMessagesTable(tenantID t.TenantID) string {
	return tenantTablePrefix(tenantID) + "messages"
}

func tenantTopicsTable(tenantID t.TenantID) string {
	return tenantTablePrefix(tenantID) + "topics"
}

func tenantGroupMembersTable(tenantID t.TenantID) string {
	return tenantTablePrefix(tenantID) + "group_members"
}

func tenantSubscriptionsTable(tenantID t.TenantID) string {
	return tenantTablePrefix(tenantID) + "subscriptions"
}

func tenantSystemNotificationsTable(tenantID t.TenantID) string {
	return tenantTablePrefix(tenantID) + "system_notifications"
}

func tenantGroupMessagesTable(tenantID t.TenantID, month string) (string, bool) {
	if !validShardMonth(month) {
		return "", false
	}
	return fmt.Sprintf("%sgroup_messages_%s", tenantTablePrefix(tenantID), month), true
}

func validShardMonth(month string) bool {
	if len(month) != 6 {
		return false
	}
	for i := range month {
		if month[i] < '0' || month[i] > '9' {
			return false
		}
	}
	return month[4:] >= "01" && month[4:] <= "12"
}