import { createHash, randomUUID } from "node:crypto";
import type { Readable } from "node:stream";

import type BetterSqlite3 from "better-sqlite3";

import type { CreditService } from "./credits.js";
import { GenerationSubmissionError } from "./generation-submission-errors.js";
import type { ManagedStorage, StagedManagedFile } from "./managed-storage.js";
import {
  defaultCanvasState,
  defaultProjectName,
  historyLimit,
  normalizePrompt,
  projectLimit,
  projectRatios,
  ratioPixels,
  stableJson,
  type ProjectRatio,
} from "./projects.js";
import { classifyCapacity } from "./storage-policy.js";

export { GenerationSubmissionError } from "./generation-submission-errors.js";

const idempotencyPattern = /^[A-Za-z0-9_-]{32,200}$/;
const uuidPattern = /^[0-9a-f]{8}-[0-9a-f]{4}-[1-8][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i;

export interface GenerationModelSnapshot {
  configSetVersion: number;
  configVersion: number;
  contractValidationStatus: "verified" | "unverified";
  creditCost: number;
  enabled: boolean;
  modelId: string;
  promptMaxLength: number;
  referenceLimits: { maxFileBytes: number; maxFiles: number; maxTotalBytes: number };
  runtimeAvailability: {
    availableForNewJobs: boolean;
    reason: "gateway_balance_insufficient" | "gateway_contract_invalid" | "model_disabled" | null;
  };
  supportedRatios: readonly ProjectRatio[];
}

export interface GenerationModelCatalog {
  readModel(modelId: string): GenerationModelSnapshot | undefined;
}

export class StaticGenerationModelCatalog implements GenerationModelCatalog {
  private readonly models = new Map<string, GenerationModelSnapshot>();

  constructor(models: GenerationModelSnapshot[]) {
    for (const model of models) this.models.set(model.modelId, structuredClone(model));
  }

  readModel(modelId: string) {
    const model = this.models.get(modelId);
    return model ? structuredClone(model) : undefined;
  }

  replace(model: GenerationModelSnapshot) {
    this.models.set(model.modelId, structuredClone(model));
  }
}

export interface NewGenerationReference {
  content: Readable;
  fileName: string;
  mimeType: "image/jpeg" | "image/png" | "image/webp";
  projectedBytes: number;
}

export interface GenerationSubmissionInput {
  clientSubmissionId: string;
  confirmedCreditCost: number;
  existingReferenceAssetIds: string[];
  idempotencyKey: string;
  mode: "new_project" | "existing_project";
  modelConfigVersion: number;
  modelId: string;
  newReferences: NewGenerationReference[];
  projectId?: string;
  prompt: string;
  ratio: ProjectRatio;
  userId: string;
}

export type GenerationSubmissionFields = Omit<GenerationSubmissionInput, "newReferences">;

export interface GenerationTaskView {
  confirmedCreditCost: number;
  createdAt: string;
  errorCategory: "upstream_timeout" | "upstream_failed" | "safety_rejected" | "model_disabled"
    | "gateway_balance_insufficient" | "gateway_contract_invalid" | "reference_invalid"
    | "unknown_retryable" | "unknown_non_retryable" | null;
  generationId: string;
  modelConfigVersion: number;
  modelId: string;
  projectId: string;
  prompt: string;
  ratio: ProjectRatio;
  referenceAssetIds: string[];
  referenceCount: number;
  reservedCredits: number;
  status: "queued" | "running" | "succeeded" | "failed" | "rejected";
  updatedAt: string;
}

export type GenerationSubmissionResult = { created: boolean; task: GenerationTaskView };

export interface GenerationUploadSession {
  abort(): void;
  commit(): Promise<GenerationSubmissionResult>;
  stageReference(reference: NewGenerationReference): Promise<void>;
}

interface GenerationRow {
  confirmed_credit_cost: number;
  created_at: number;
  error_category: GenerationTaskView["errorCategory"];
  generation_id: string;
  model_config_version: number;
  model_id: string;
  owner_id: string;
  project_id: string;
  prompt: string;
  ratio: ProjectRatio;
  reserved_credits: number;
  status: "queued" | "running" | "succeeded" | "failed" | "rejected";
  updated_at: number;
}

function iso(timestamp: number) {
  return new Date(timestamp).toISOString();
}

function digest(value: string) {
  return createHash("sha256").update(value, "utf8").digest("hex");
}

function safeInteger(value: number) {
  return Number.isSafeInteger(value) && value > 0;
}

export class GenerationSubmissionService {
  readonly database: BetterSqlite3.Database;
  private readonly beforeTransaction: (() => Promise<void>) | undefined;
  private readonly clock: () => number;
  private readonly credits: CreditService;
  private readonly models: GenerationModelCatalog;
  private readonly storage: ManagedStorage;

  constructor(input: {
    beforeTransaction?: () => Promise<void>;
    clock?: () => number;
    credits: CreditService;
    models: GenerationModelCatalog;
    storage: ManagedStorage;
  }) {
    this.beforeTransaction = input.beforeTransaction;
    this.clock = input.clock ?? Date.now;
    this.credits = input.credits;
    this.database = input.credits.database;
    this.models = input.models;
    this.storage = input.storage;
    this.migrate();
  }

  close() {
    // The database connection is owned by CreditService.
  }

  readCurrentTask(userId: string) {
    const row = this.database.prepare(`
      SELECT * FROM generation_jobs
      WHERE owner_id = ? AND status IN ('queued', 'running') AND submission_ready = 1
      ORDER BY created_at DESC, generation_id DESC LIMIT 1
    `).get(userId) as GenerationRow | undefined;
    return row ? this.taskView(row) : undefined;
  }

  readTask(userId: string, generationId: string) {
    const row = this.database.prepare(`
      SELECT * FROM generation_jobs WHERE generation_id = ? AND owner_id = ? AND submission_ready = 1
    `).get(generationId, userId) as GenerationRow | undefined;
    if (!row) throw new GenerationSubmissionError("generation_not_found");
    return this.taskView(row);
  }

  async submit(input: GenerationSubmissionInput): Promise<GenerationSubmissionResult> {
    const current = this.readCurrentTask(input.userId);
    if (current) return { created: false as const, task: current };
    const { newReferences, ...fields } = input;
    const upload = this.beginUpload(fields);
    try {
      for (const reference of newReferences) await upload.stageReference(reference);
      return await upload.commit();
    } catch (error) {
      upload.abort();
      throw error;
    }
  }

  beginUpload(input: GenerationSubmissionFields): GenerationUploadSession {
    const preflightModel = this.validate({ ...input, newReferences: [] });
    const staged: StagedManagedFile[] = [];
    let finished = false;
    const abort = () => {
      if (finished) return;
      finished = true;
      for (const file of staged) this.storage.abandonStagedFile(file);
    };
    return {
      abort,
      commit: async () => {
        if (finished) throw new GenerationSubmissionError("generation_request_invalid");
        if (this.beforeTransaction) await this.beforeTransaction();
        try {
          const result = this.immediate(() => this.commitSubmission({ ...input, newReferences: [] }, staged));
          if (result.created) finished = true;
          else abort();
          return result;
        } catch (error) {
          abort();
          throw error;
        }
      },
      stageReference: async (reference) => {
        if (finished) throw new GenerationSubmissionError("generation_request_invalid");
        const nextCount = input.existingReferenceAssetIds.length + staged.length + 1;
        const nextBytes = staged.reduce((sum, file) => sum + file.bytes, 0) + reference.projectedBytes;
        if (nextCount > preflightModel.referenceLimits.maxFiles || nextBytes > preflightModel.referenceLimits.maxTotalBytes
          || !safeInteger(reference.projectedBytes) || reference.projectedBytes > preflightModel.referenceLimits.maxFileBytes) {
          throw new GenerationSubmissionError("reference_invalid", { errorCategory: "reference_invalid" });
        }
        try {
          staged.push(await this.storage.stagePrivateImage({
            content: reference.content,
            expectedMimeType: reference.mimeType,
            fileName: reference.fileName,
            maximumBytes: preflightModel.referenceLimits.maxFileBytes,
            operationId: randomUUID(),
            ownerRef: input.userId,
            projectedWriteBytes: reference.projectedBytes,
          }));
        } catch (error) {
          if (error instanceof GenerationSubmissionError || (error && typeof error === "object" && "code" in error)) throw error;
          throw new GenerationSubmissionError("reference_invalid", { errorCategory: "reference_invalid" });
        }
      },
    };
  }

  private validate(input: GenerationSubmissionInput) {
    if (!uuidPattern.test(input.userId) || !uuidPattern.test(input.clientSubmissionId)
      || !idempotencyPattern.test(input.idempotencyKey) || !projectRatios.includes(input.ratio)
      || !safeInteger(input.modelConfigVersion) || !safeInteger(input.confirmedCreditCost)
      || (input.mode === "existing_project" && (!input.projectId || !uuidPattern.test(input.projectId)))
      || (input.mode === "new_project" && input.projectId !== undefined)) {
      throw new GenerationSubmissionError("generation_request_invalid");
    }
    const prompt = normalizePrompt(input.prompt);
    const model = this.models.readModel(input.modelId);
    if (!model) throw new GenerationSubmissionError("generation_blocked", { errorCategory: "model_disabled" });
    const workerState = this.database.prepare("SELECT status FROM worker_runtime_state WHERE singleton = 1").get() as { status: "ready" | "degraded" } | undefined;
    if (workerState?.status === "degraded") throw new GenerationSubmissionError("generation_blocked", { errorCategory: "gateway_contract_invalid" });
    if (model.configVersion !== input.modelConfigVersion || model.creditCost !== input.confirmedCreditCost) {
      throw new GenerationSubmissionError("model_config_stale", {
        latest: { configVersion: model.configVersion, creditCost: model.creditCost, modelId: model.modelId },
      });
    }
    if (!model.enabled) throw new GenerationSubmissionError("generation_blocked", { errorCategory: "model_disabled" });
    if (model.contractValidationStatus !== "verified") {
      throw new GenerationSubmissionError("generation_blocked", { errorCategory: "gateway_contract_invalid" });
    }
    if (!model.runtimeAvailability.availableForNewJobs) {
      throw new GenerationSubmissionError("generation_blocked", { errorCategory: model.runtimeAvailability.reason ?? "model_disabled" });
    }
    if (prompt.length > model.promptMaxLength || !model.supportedRatios.includes(input.ratio)) {
      throw new GenerationSubmissionError("generation_request_invalid");
    }
    const referenceCount = input.newReferences.length + input.existingReferenceAssetIds.length;
    const projectedBytes = input.newReferences.reduce((sum, reference) => sum + reference.projectedBytes, 0);
    if (referenceCount > model.referenceLimits.maxFiles || projectedBytes > model.referenceLimits.maxTotalBytes
      || input.newReferences.some((reference) => !safeInteger(reference.projectedBytes) || reference.projectedBytes > model.referenceLimits.maxFileBytes)
      || new Set(input.existingReferenceAssetIds).size !== input.existingReferenceAssetIds.length
      || input.existingReferenceAssetIds.some((id) => !uuidPattern.test(id))
      || (input.mode === "new_project" && input.existingReferenceAssetIds.length > 0)) {
      throw new GenerationSubmissionError("reference_invalid", { errorCategory: "reference_invalid" });
    }
    const storageState = this.storage.getState();
    if (storageState.storage_status !== "active") {
      throw new GenerationSubmissionError("generation_storage_unavailable", {
        storage: {
          capacityStatus: storageState.storage_status,
          remainingBytes: Math.max(
            0,
            storageState.hard_limit_bytes - storageState.managed_content_bytes - storageState.active_storage_reservations_bytes,
          ),
        },
      });
    }
    return model;
  }

  private commitSubmission(input: GenerationSubmissionInput, staged: StagedManagedFile[]) {
    const model = this.validate(input);
    const requestHash = digest(stableJson({
      client_submission_id: input.clientSubmissionId,
      confirmed_credit_cost: input.confirmedCreditCost,
      existing_reference_asset_ids: input.existingReferenceAssetIds,
      mode: input.mode,
      model_config_version: input.modelConfigVersion,
      model_id: input.modelId,
      new_references: staged.map((file) => ({ bytes: file.bytes, mime_type: file.mimeType, sha256: file.sha256 })),
      project_id: input.projectId ?? null,
      prompt: normalizePrompt(input.prompt),
      ratio: input.ratio,
    }));
    const keyDigest = digest(input.idempotencyKey);
    const receipt = this.database.prepare(`
      SELECT r.request_hash, g.* FROM generation_submission_receipts r
      JOIN generation_jobs g ON g.generation_id = r.generation_id
      WHERE r.owner_id = ? AND r.idempotency_key_digest = ?
    `).get(input.userId, keyDigest) as (GenerationRow & { request_hash: string }) | undefined;
    if (receipt) {
      if (receipt.request_hash !== requestHash) throw new GenerationSubmissionError("generation_idempotency_conflict");
      return { created: false as const, task: this.taskView(receipt) };
    }
    const bySubmission = this.database.prepare("SELECT * FROM generation_jobs WHERE client_submission_id = ?")
      .get(input.clientSubmissionId) as (GenerationRow & { submission_request_hash: string | null }) | undefined;
    if (bySubmission) {
      if (bySubmission.submission_request_hash !== requestHash || bySubmission.owner_id !== input.userId) {
        throw new GenerationSubmissionError("generation_idempotency_conflict");
      }
      return { created: false as const, task: this.taskView(bySubmission) };
    }
    const current = this.readCurrentTask(input.userId);
    if (current) return { created: false as const, task: current };

    const now = this.clock();
    const prompt = normalizePrompt(input.prompt);
    const generationId = randomUUID();
    const projectId = input.mode === "new_project"
      ? this.insertProject(input.userId, prompt, input.ratio, now)
      : this.validateExistingProject(input.userId, input.projectId!, input.ratio, prompt, now);
    this.database.prepare(`
      INSERT INTO generation_jobs (
        generation_id, owner_id, project_id, prompt, ratio, status, model_id, model_config_version,
        confirmed_credit_cost, reserved_credits, final_credit_state, error_category, created_at, updated_at,
        client_submission_id, submission_request_hash, submission_ready, config_snapshot_json
      ) VALUES (?, ?, ?, ?, ?, 'queued', ?, ?, ?, 0, NULL, NULL, ?, ?, ?, ?, 0, ?)
    `).run(
      generationId, input.userId, projectId, prompt, input.ratio, input.modelId, input.modelConfigVersion,
      input.confirmedCreditCost, now, now, input.clientSubmissionId, requestHash,
      stableJson({
        config_set_version: model.configSetVersion,
        config_version: model.configVersion,
        credit_cost: model.creditCost,
        model_id: model.modelId,
        prompt_max_length: model.promptMaxLength,
        reference_limits: model.referenceLimits,
        supported_ratios: model.supportedRatios,
      }),
    );

    const referenceIds: string[] = [];
    for (const file of staged) {
      this.storage.moveStagedFile(file);
      this.database.prepare(`
        INSERT INTO managed_files (file_id, file_kind, owner_ref, relative_path, byte_size, mime_type, sha256, status, created_at)
        VALUES (?, 'reference', ?, ?, ?, ?, ?, 'committed', ?)
      `).run(file.fileId, input.userId, file.relativePath, file.bytes, file.mimeType, file.sha256, iso(now));
      this.database.prepare(`INSERT INTO project_resource_files (project_id, managed_file_id, resource_kind, created_at) VALUES (?, ?, 'reference', ?)`)
        .run(projectId, file.fileId, now);
      this.database.prepare(`INSERT INTO project_asset_refs (reference_id, managed_file_id, reference_type, created_at) VALUES (?, ?, 'project', ?)`)
        .run(`project:${projectId}:${file.fileId}`, file.fileId, iso(now));
      referenceIds.push(file.fileId);
    }
    for (const referenceId of input.existingReferenceAssetIds) {
      const allowed = this.database.prepare(`
        SELECT mf.file_id FROM managed_files mf
        JOIN project_resource_files prf ON prf.managed_file_id = mf.file_id
        JOIN projects p ON p.project_id = prf.project_id
        WHERE mf.file_id = ? AND mf.file_kind = 'reference' AND mf.status = 'committed'
          AND mf.owner_ref = ? AND prf.project_id = ? AND p.owner_id = ? AND p.status = 'active'
      `).get(referenceId, input.userId, projectId, input.userId);
      if (!allowed) throw new GenerationSubmissionError("reference_invalid", { errorCategory: "reference_invalid" });
      referenceIds.push(referenceId);
    }
    referenceIds.forEach((referenceId, index) => this.database.prepare(`
      INSERT INTO generation_reference_snapshots (generation_id, position, managed_file_id, source_kind, created_at)
      VALUES (?, ?, ?, ?, ?)
    `).run(generationId, index, referenceId, index < staged.length ? "uploaded" : "existing", now));

    this.credits.reserveGeneration({
      creditCost: input.confirmedCreditCost,
      generationId,
      modelId: input.modelId,
      operationKey: `generation:${generationId}:reserve`,
      userId: input.userId,
    });
    this.database.prepare("UPDATE generation_jobs SET submission_ready = 1 WHERE generation_id = ?").run(generationId);
    this.database.prepare(`
      INSERT INTO generation_submission_receipts (owner_id, idempotency_key_digest, request_hash, generation_id, created_at)
      VALUES (?, ?, ?, ?, ?)
    `).run(input.userId, keyDigest, requestHash, generationId, now);
    this.consumeStagedStorage(staged, now);
    return { created: true as const, task: this.readTask(input.userId, generationId) };
  }

  private insertProject(ownerId: string, prompt: string, ratio: ProjectRatio, now: number) {
    const active = this.database.prepare("SELECT COUNT(*) AS count FROM projects WHERE owner_id = ? AND status = 'active'")
      .get(ownerId) as { count: number };
    if (active.count >= projectLimit) throw new GenerationSubmissionError("generation_request_invalid");
    const projectId = randomUUID();
    const pixels = ratioPixels[ratio];
    const name = defaultProjectName(prompt, now);
    this.database.prepare(`
      INSERT INTO projects (
        project_id, owner_id, name, draft_prompt, ratio, pixel_width, pixel_height,
        status, state_version, current_image_id, created_at, updated_at, deleted_at, purge_at
      ) VALUES (?, ?, ?, ?, ?, ?, ?, 'active', 1, NULL, ?, ?, NULL, NULL)
    `).run(projectId, ownerId, name, prompt, ratio, pixels.width, pixels.height, now, now);
    this.database.prepare(`
      INSERT INTO project_states (project_id, state_version, name, canvas_json, created_at) VALUES (?, 1, ?, ?, ?)
    `).run(projectId, name, stableJson(defaultCanvasState(ratio, pixels, null)), now);
    return projectId;
  }

  private validateExistingProject(ownerId: string, projectId: string, ratio: ProjectRatio, prompt: string, now: number) {
    const project = this.database.prepare("SELECT ratio FROM projects WHERE project_id = ? AND owner_id = ? AND status = 'active'")
      .get(projectId, ownerId) as { ratio: ProjectRatio } | undefined;
    if (!project || project.ratio !== ratio) throw new GenerationSubmissionError("generation_request_invalid");
    const history = this.database.prepare("SELECT COUNT(*) AS count FROM project_images WHERE project_id = ?").get(projectId) as { count: number };
    if (history.count >= historyLimit) throw new GenerationSubmissionError("generation_request_invalid");
    this.database.prepare("UPDATE projects SET draft_prompt = ?, updated_at = ? WHERE project_id = ?").run(prompt, now, projectId);
    return projectId;
  }

  private consumeStagedStorage(staged: StagedManagedFile[], now: number) {
    if (staged.length === 0) return;
    const total = staged.reduce((sum, file) => sum + file.bytes, 0);
    for (const file of staged) {
      this.database.prepare(`
        UPDATE storage_reservations SET status = 'consumed', resolved_at = ?
        WHERE operation_id = ? AND status = 'active'
      `).run(iso(now), file.operationId);
    }
    const state = this.database.prepare("SELECT managed_content_bytes FROM local_backend_storage_state WHERE singleton = 1")
      .get() as { managed_content_bytes: number };
    const active = this.database.prepare("SELECT COALESCE(SUM(projected_bytes), 0) AS bytes FROM storage_reservations WHERE status = 'active'")
      .get() as { bytes: number };
    const nextBytes = state.managed_content_bytes + total;
    const classification = classifyCapacity(nextBytes, active.bytes);
    this.database.prepare(`
      UPDATE local_backend_storage_state
      SET managed_content_bytes = ?, capacity_notice_level = ?, storage_status = ?, measured_at = ?, version = version + 1
      WHERE singleton = 1
    `).run(nextBytes, classification.capacity_notice_level, classification.storage_status, iso(now));
  }

  private taskView(row: GenerationRow): GenerationTaskView {
    const referenceAssetIds = (this.database.prepare(`
      SELECT managed_file_id FROM generation_reference_snapshots WHERE generation_id = ? ORDER BY position
    `).all(row.generation_id) as Array<{ managed_file_id: string }>).map((entry) => entry.managed_file_id);
    return {
      confirmedCreditCost: row.confirmed_credit_cost,
      createdAt: iso(row.created_at),
      errorCategory: row.error_category,
      generationId: row.generation_id,
      modelConfigVersion: row.model_config_version,
      modelId: row.model_id,
      projectId: row.project_id,
      prompt: row.prompt,
      ratio: row.ratio,
      referenceAssetIds,
      referenceCount: referenceAssetIds.length,
      reservedCredits: row.reserved_credits,
      status: row.status,
      updatedAt: iso(row.updated_at),
    };
  }

  private immediate<T>(action: () => T): T {
    this.database.exec("BEGIN IMMEDIATE");
    try {
      const result = action();
      this.database.exec("COMMIT");
      return result;
    } catch (error) {
      if (this.database.inTransaction) this.database.exec("ROLLBACK");
      throw error;
    }
  }

  private ensureColumn(table: string, column: string, definition: string) {
    const columns = this.database.prepare(`PRAGMA table_info(${table})`).all() as Array<{ name: string }>;
    if (!columns.some((value) => value.name === column)) this.database.exec(`ALTER TABLE ${table} ADD COLUMN ${column} ${definition}`);
  }

  private migrate() {
    this.ensureColumn("generation_jobs", "client_submission_id", "TEXT");
    this.ensureColumn("generation_jobs", "submission_request_hash", "TEXT");
    this.ensureColumn("generation_jobs", "submission_ready", "INTEGER NOT NULL DEFAULT 0");
    this.ensureColumn("generation_jobs", "config_snapshot_json", "TEXT");
    this.database.exec(`
      CREATE TABLE IF NOT EXISTS worker_runtime_state (
        singleton INTEGER PRIMARY KEY CHECK (singleton = 1),
        status TEXT NOT NULL CHECK (status IN ('ready', 'degraded')),
        reason TEXT,
        owner_id TEXT,
        lock_expires_at INTEGER,
        updated_at INTEGER NOT NULL
      );
      CREATE UNIQUE INDEX IF NOT EXISTS generation_jobs_active_owner
      ON generation_jobs(owner_id) WHERE status IN ('queued', 'running');
      CREATE UNIQUE INDEX IF NOT EXISTS generation_jobs_client_submission
      ON generation_jobs(client_submission_id) WHERE client_submission_id IS NOT NULL;
      CREATE TABLE IF NOT EXISTS generation_submission_receipts (
        owner_id TEXT NOT NULL,
        idempotency_key_digest TEXT NOT NULL CHECK (length(idempotency_key_digest) = 64),
        request_hash TEXT NOT NULL CHECK (length(request_hash) = 64),
        generation_id TEXT NOT NULL UNIQUE REFERENCES generation_jobs(generation_id),
        created_at INTEGER NOT NULL,
        PRIMARY KEY (owner_id, idempotency_key_digest)
      );
      CREATE TABLE IF NOT EXISTS generation_reference_snapshots (
        generation_id TEXT NOT NULL REFERENCES generation_jobs(generation_id) ON DELETE CASCADE,
        position INTEGER NOT NULL CHECK (position >= 0),
        managed_file_id TEXT NOT NULL REFERENCES managed_files(file_id),
        source_kind TEXT NOT NULL CHECK (source_kind IN ('uploaded', 'existing')),
        created_at INTEGER NOT NULL,
        PRIMARY KEY (generation_id, position),
        UNIQUE (generation_id, managed_file_id)
      );
      CREATE TRIGGER IF NOT EXISTS generation_reference_snapshots_no_update
      BEFORE UPDATE ON generation_reference_snapshots BEGIN SELECT RAISE(ABORT, 'generation_reference_snapshot_immutable'); END;
      DROP TRIGGER IF EXISTS generation_reference_snapshots_no_delete;
      CREATE TRIGGER generation_reference_snapshots_no_delete
      BEFORE DELETE ON generation_reference_snapshots
      WHEN dada_allow_privacy_purge() <> 1
      BEGIN SELECT RAISE(ABORT, 'generation_reference_snapshot_immutable'); END;
    `);
    this.ensureColumn("worker_runtime_state", "owner_id", "TEXT");
    this.ensureColumn("worker_runtime_state", "lock_expires_at", "INTEGER");
    this.database.prepare("INSERT OR IGNORE INTO worker_runtime_state (singleton, status, reason, owner_id, lock_expires_at, updated_at) VALUES (1, 'ready', NULL, NULL, NULL, ?)").run(this.clock());
  }
}