import { sql } from "drizzle-orm";
import {
  index,
  int,
  sqliteTable,
  text,
  type AnySQLiteColumn,
} from "drizzle-orm/sqlite-core";

/**
 * Represents chat conversations in the system using string IDs for better
 * compatibility with AI SDK and modern chat applications.
 *
 * Chats can be organized hierarchically using parentId references and
 * support status tracking for real-time conversation management.
 */
export const chats = sqliteTable(
  "chats",
  {
    /** Unique identifier for the chat - compatible with UIMessage chatId */
    id: text().primaryKey(),

    /** The title/name of the chat conversation */
    title: text().notNull(),

    /** Timestamp (in milliseconds) when the chat was created */
    createdAt: int("created_at")
      .notNull()
      .default(sql`CURRENT_TIMESTAMP`),

    /** Timestamp when the chat was last updated */
    updatedAt: int("updated_at")
      .notNull()
      .default(sql`CURRENT_TIMESTAMP`),

    /** Optional reference to a parent chat, allowing for hierarchical chat organization */
    parentId: text().references((): AnySQLiteColumn => chats.id, {
      onDelete: "cascade",
    }),

    /** Current status of the chat conversation */
    status: text()
      .notNull()
      .default("idle")
      .$type<"idle" | "in_progress" | "completed" | "error">(),
  },
  (table) => ({
    parentIdx: index("idx_chats_parent_id").on(table.parentId),
    statusIdx: index("idx_chats_status").on(table.status),
    updatedAtIdx: index("idx_chats_updated_at").on(table.updatedAt),
  })
);