import * as fs from "node:fs";
import * as path from "node:path";
import type { EngineName } from "./config";
import type { PageKind } from "./parse";

// Per-engine counters. No queries or URLs are stored here.
export interface EngineHealth {
  okCount: number;
  failCount: number;
  captchaCount: number;
  consecutiveFailures: number;
  lastOk?: string;
  lastFailure?: string;
  lastFailureKind?: string;
  lastCaptcha?: string;
}

type HealthFile = Partial<Record<EngineName, EngineHealth>>;

export class HealthStore {
  private file: string;
  private data: HealthFile;

  constructor(dataDir: string) {
    this.file = path.join(dataDir, "health.json");
    try {
      this.data = JSON.parse(fs.readFileSync(this.file, "utf8")) as HealthFile;
    } catch {
      this.data = {};
    }
  }

  get(engine: EngineName): EngineHealth {
    return this.data[engine] ?? { okCount: 0, failCount: 0, captchaCount: 0, consecutiveFailures: 0 };
  }

  record(engine: EngineName, kind: PageKind | "error"): void {
    const h = this.get(engine);
    const now = new Date().toISOString();
    if (kind === "ok" || kind === "no_results") {
      h.okCount++;
      h.consecutiveFailures = 0;
      h.lastOk = now;
    } else if (kind === "captcha") {
      h.captchaCount++;
      h.lastCaptcha = now;
    } else {
      h.failCount++;
      h.consecutiveFailures++;
      h.lastFailure = now;
      h.lastFailureKind = kind;
    }
    this.data[engine] = h;
    try {
      fs.mkdirSync(path.dirname(this.file), { recursive: true });
      fs.writeFileSync(this.file, JSON.stringify(this.data, null, 2), "utf8");
    } catch {
      // health tracking is best effort
    }
  }

  describe(engine: EngineName): string {
    const h = this.get(engine);
    if (!h.okCount && !h.failCount && !h.captchaCount) return "no searches recorded yet";
    const parts = [`${h.okCount} ok, ${h.failCount} failed, ${h.captchaCount} captcha`];
    if (h.consecutiveFailures) {
      parts.push(`failing ${h.consecutiveFailures} time(s) in a row (last: ${h.lastFailureKind} at ${h.lastFailure})`);
    } else if (h.lastOk) {
      parts.push(`last ok ${h.lastOk}`);
    }
    return parts.join("; ");
  }
}

import * as fs from "node:fs";
import * as path from "node:path";
import type { EngineName } from "./config";
import type { PageKind } from "./parse";

// Per-engine counters. No queries or URLs are stored here.
export interface EngineHealth {
  okCount: number;
  failCount: number;
  captchaCount: number;
  consecutiveFailures: number;
  lastOk?: string;
  lastFailure?: string;
  lastFailureKind?: string;
  lastCaptcha?: string;
}

type HealthFile = Partial<Record<EngineName, EngineHealth>>;

export class HealthStore {
  private file: string;
  private data: HealthFile;

  constructor(dataDir: string) {
    this.file = path.join(dataDir, "health.json");
    try {
      this.data = JSON.parse(fs.readFileSync(this.file, "utf8")) as HealthFile;
    } catch {
      this.data = {};
    }
  }

  get(engine: EngineName): EngineHealth {
    return this.data[engine] ?? { okCount: 0, failCount: 0, captchaCount: 0, consecutiveFailures: 0 };
  }

  record(engine: EngineName, kind: PageKind | "error"): void {
    const h = this.get(engine);
    const now = new Date().toISOString();
    if (kind === "ok" || kind === "no_results") {
      h.okCount++;
      h.consecutiveFailures = 0;
      h.lastOk = now;
    } else if (kind === "captcha") {
      h.captchaCount++;
      h.lastCaptcha = now;
    } else {
      h.failCount++;
      h.consecutiveFailures++;
      h.lastFailure = now;
      h.lastFailureKind = kind;
    }
    this.data[engine] = h;
    try {
      fs.mkdirSync(path.dirname(this.file), { recursive: true });
      fs.writeFileSync(this.file, JSON.stringify(this.data, null, 2), "utf8");
    } catch {
      // health tracking is best effort
    }
  }

  describe(engine: EngineName): string {
    const h = this.get(engine);
    if (!h.okCount && !h.failCount && !h.captchaCount) return "no searches recorded yet";
    const parts = [`${h.okCount} ok, ${h.failCount} failed, ${h.captchaCount} captcha`];
    if (h.consecutiveFailures) {
      parts.push(`failing ${h.consecutiveFailures} time(s) in a row (last: ${h.lastFailureKind} at ${h.lastFailure})`);
    } else if (h.lastOk) {
      parts.push(`last ok ${h.lastOk}`);
    }
    return parts.join("; ");
  }
}