/**
 * Drizzle Agent Repository Adapter
 *
 * Implements AgentRepository interface using Drizzle ORM.
 */

import { eq, getTableColumns } from 'drizzle-orm';
import { nanoid } from 'nanoid';
import type { DrizzleDatabase } from '../../index.js';
import { agents, tasks, phases, initiatives, type Agent } from '../../schema.js';
import type {
  AgentRepository,
  AgentStatus,
  AgentWithContext,
  CreateAgentData,
  UpdateAgentData,
} from '../agent-repository.js';

/**
 * Drizzle adapter for AgentRepository.
 *
 * Uses dependency injection for database instance,
 * enabling isolated test databases.
 */
export class DrizzleAgentRepository implements AgentRepository {
  constructor(private db: DrizzleDatabase) {}

  async create(data: CreateAgentData): Promise<Agent> {
    const id = nanoid();
    const now = new Date();

    const [created] = await this.db.insert(agents).values({
      id,
      name: data.name,
      taskId: data.taskId ?? null,
      initiativeId: data.initiativeId ?? null,
      sessionId: data.sessionId ?? null,
      worktreeId: data.worktreeId,
      provider: data.provider ?? 'claude',
      accountId: data.accountId ?? null,
      status: data.status ?? 'idle',
      mode: data.mode ?? 'execute',
      createdAt: now,
      updatedAt: now,
    }).returning();

    return created;
  }

  async findById(id: string): Promise<Agent | null> {
    const result = await this.db
      .select()
      .from(agents)
      .where(eq(agents.id, id))
      .limit(1);

    return result[0] ?? null;
  }

  async findByName(name: string): Promise<Agent | null> {
    const result = await this.db
      .select()
      .from(agents)
      .where(eq(agents.name, name))
      .limit(1);

    return result[0] ?? null;
  }

  async findByTaskId(taskId: string): Promise<Agent | null> {
    const result = await this.db
      .select()
      .from(agents)
      .where(eq(agents.taskId, taskId))
      .limit(1);

    return result[0] ?? null;
  }

  async findBySessionId(sessionId: string): Promise<Agent | null> {
    const result = await this.db
      .select()
      .from(agents)
      .where(eq(agents.sessionId, sessionId))
      .limit(1);

    return result[0] ?? null;
  }

  async findAll(): Promise<Agent[]> {
    return this.db.select().from(agents);
  }

  async findByStatus(status: AgentStatus): Promise<Agent[]> {
    return this.db.select().from(agents).where(eq(agents.status, status));
  }

  async update(id: string, data: UpdateAgentData): Promise<Agent> {
    const now = new Date();
    const [updated] = await this.db
      .update(agents)
      .set({ ...data, updatedAt: now })
      .where(eq(agents.id, id))
      .returning();

    if (!updated) {
      throw new Error(`Agent not found: ${id}`);
    }

    return updated;
  }

  async delete(id: string): Promise<void> {
    const [deleted] = await this.db.delete(agents).where(eq(agents.id, id)).returning();

    if (!deleted) {
      throw new Error(`Agent not found: ${id}`);
    }
  }

  async findWaitingWithContext(): Promise<AgentWithContext[]> {
    return this.db
      .select({
        ...getTableColumns(agents),
        taskName: tasks.name,
        phaseName: phases.name,
        initiativeName: initiatives.name,
        taskDescription: tasks.description,
      })
      .from(agents)
      .where(eq(agents.status, 'waiting_for_input'))
      .leftJoin(tasks, eq(agents.taskId, tasks.id))
      .leftJoin(phases, eq(tasks.phaseId, phases.id))
      .leftJoin(initiatives, eq(agents.initiativeId, initiatives.id));
  }
}