import { db } from "@/lib/db/client"

export type MemberMutationResult =
  | { status: "updated"; memberId: string }
  | { status: "deleted"; memberId: string }
  | { status: "not_found" }
  | { status: "last_member" }

export async function listInvitationMembers(invitationId: string) {
  return db
    .selectFrom("invitation_members")
    .selectAll()
    .where("invitation_id", "=", invitationId)
    .orderBy("is_primary_contact", "desc")
    .orderBy("created_at", "asc")
    .execute()
}

export async function updateInvitationMemberName({
  invitationId,
  memberId,
  name,
  adminEmail,
}: {
  invitationId: string
  memberId: string
  name: string
  adminEmail: string
}): Promise<MemberMutationResult> {
  return db.transaction().execute(async (trx) => {
    const member = await trx
      .selectFrom("invitation_members")
      .innerJoin("invitations", "invitations.id", "invitation_members.invitation_id")
      .select(["invitation_members.id", "invitation_members.name", "invitations.display_name"])
      .where("invitation_members.id", "=", memberId)
      .where("invitation_members.invitation_id", "=", invitationId)
      .executeTakeFirst()

    if (!member) return { status: "not_found" }

    const updated = await trx
      .updateTable("invitation_members")
      .set({ name, updated_at: new Date() })
      .where("id", "=", memberId)
      .where("invitation_id", "=", invitationId)
      .returning("id")
      .executeTakeFirst()

    if (!updated) return { status: "not_found" }

    await trx
      .updateTable("invitations")
      .set({ updated_at: new Date() })
      .where("id", "=", invitationId)
      .execute()

    await trx
      .insertInto("admin_audit_events")
      .values({
        admin_email: adminEmail,
        action: "invitation_member.updated",
        target_type: "invitation_member",
        target_id: memberId,
        metadata: {
          invitationId,
          displayName: member.display_name,
          previousName: member.name,
          newName: name,
        },
      })
      .execute()

    return { status: "updated", memberId }
  })
}

export async function deleteInvitationMember({
  invitationId,
  memberId,
  adminEmail,
}: {
  invitationId: string
  memberId: string
  adminEmail: string
}): Promise<MemberMutationResult> {
  return db.transaction().execute(async (trx) => {
    const member = await trx
      .selectFrom("invitation_members")
      .innerJoin("invitations", "invitations.id", "invitation_members.invitation_id")
      .select([
        "invitation_members.id",
        "invitation_members.name",
        "invitation_members.is_primary_contact",
        "invitations.display_name",
      ])
      .where("invitation_members.id", "=", memberId)
      .where("invitation_members.invitation_id", "=", invitationId)
      .executeTakeFirst()

    if (!member) return { status: "not_found" }

    const count = await trx
      .selectFrom("invitation_members")
      .select((eb) => eb.fn.countAll<string>().as("count"))
      .where("invitation_id", "=", invitationId)
      .executeTakeFirstOrThrow()
    const memberCount = Number(count.count)

    if (memberCount <= 1) return { status: "last_member" }

    let promotedMemberId: string | null = null
    if (member.is_primary_contact) {
      const replacement = await trx
        .selectFrom("invitation_members")
        .select(["id"])
        .where("invitation_id", "=", invitationId)
        .where("id", "!=", memberId)
        .orderBy("created_at", "asc")
        .executeTakeFirst()

      if (replacement) {
        promotedMemberId = replacement.id
        await trx
          .updateTable("invitation_members")
          .set({ is_primary_contact: true, updated_at: new Date() })
          .where("id", "=", replacement.id)
          .execute()
      }
    }

    const deleted = await trx
      .deleteFrom("invitation_members")
      .where("id", "=", memberId)
      .where("invitation_id", "=", invitationId)
      .returning("id")
      .executeTakeFirst()

    if (!deleted) return { status: "not_found" }

    await trx
      .updateTable("invitations")
      .set({ updated_at: new Date() })
      .where("id", "=", invitationId)
      .execute()

    await trx
      .insertInto("admin_audit_events")
      .values({
        admin_email: adminEmail,
        action: "invitation_member.deleted",
        target_type: "invitation_member",
        target_id: memberId,
        metadata: {
          invitationId,
          displayName: member.display_name,
          name: member.name,
          wasPrimary: member.is_primary_contact,
          promotedMemberId,
          remainingMembers: memberCount - 1,
        },
      })
      .execute()

    return { status: "deleted", memberId }
  })
}