// POST /relay/analyze — forwards an analysis prompt to the chosen
// backend and returns the standard envelope.
//
// Request body (application/json):
//   { prompt: string }
//
// Headers: same as /relay/transcribe (X-Recap-Install-Id required,
// X-Recap-Job-Id optional, Authorization optional Bearer license).
//
// Same charge-once-per-job semantics: a Recap summarize job pairs
// transcribe + analyze with the same X-Recap-Job-Id. The first call
// (whichever endpoint) charges 1 credit; the second is free.
//
// Every outcome (success / quota-refused / backend-error) writes one
// row to the audit log so the admin dashboard can compute cost,
// margin, and speed metrics.

import express from "express";
import { resolveIdentity, identityTier } from "../identity.js";
import {
  getOrCreateRow,
  planBackend,
  commitCredit,
  licenseFingerprint,
} from "../credits.js";
import { lookupJob, markJobCharged, refundJob } from "../job-credits.js";
import { getConfigSnapshot, getTierQuotas } from "../config.js";
import { createGeminiBackend } from "../backends/gemini.js";
import { createHardwareBackend } from "../backends/hardware.js";
import { envelope, errorEnvelope } from "./envelope.js";
import { recordCall } from "../audit-log.js";
import { resolveHardwareConfig } from "../hardware-config.js";
import { reportHealthEvent } from "../spark-control-events.js";
import { calcGeminiCost } from "../pricing.js";

export function analyzeRouter() {
  const router = express.Router();

  router.post("/analyze", express.json({ limit: "10mb" }), async (req, res) => {
    const t0 = Date.now();
    const jobId = req.header("X-Recap-Job-Id") || null;

    let identity;
    try {
      identity = await resolveIdentity(req);
    } catch (err) {
      const e = await errorEnvelope({
        error: err?.message || "auth_error",
        statusHint: err?.status || 401,
      });
      return res.status(e.statusHint || 401).json(e.body);
    }
    if (identity.kind === "license" && !identity.installId) {
      const e = await errorEnvelope({
        error: "missing X-Recap-Install-Id header",
        statusHint: 400,
      });
      return res.status(400).json(e.body);
    }
    const { creditKey, installId, license } = identity;
    const prompt = req.body?.prompt;
    if (!prompt || typeof prompt !== "string") {
      const e = await errorEnvelope({
        error: "missing or non-string body.prompt",
        creditKey,
        installId,
        statusHint: 400,
      });
      return res.status(400).json(e.body);
    }

    const row = await getOrCreateRow({ creditKey, installId, license });
    const tier = identityTier(identity, row);
    row.tier_snapshot = tier;
    const licenseFp = identity.kind === "cloud" ? null : licenseFingerprint(license);
    const auditInstall = installId || identity.userId || null;

    // Two separate decisions on every call:
    //   1. Billing: did we already charge a credit for this job? (look
    //      up by job_id; reused → don't charge again.)
    //   2. Routing: which backend serves THIS pipeline step's request?
    //      (always per-pipeline preference + planBackend, even when
    //      the job has a prior transcribe call that routed elsewhere.)
    //
    // The old code conflated the two — it copied `backend` from the
    // existing job, which meant analyze would silently inherit
    // transcribe's backend choice even when the operator's analyze
    // preference said something different. Fixed: routing is decided
    // fresh per pipeline step, regardless of job history.
    const reusedJob = !!lookupJob({ creditKey, installId, license, jobId });
    const cfg = await getConfigSnapshot();
    const hw = await resolveHardwareConfig(cfg);
    // Operator-only diagnostic — see summarize-url.js for the full
    // reasoning. We don't 503 here on blocked_reason because doing
    // so pre-empts planBackend and would surface operator-internal
    // Spark Control / vLLM wording to clients even when Gemini was
    // the configured preference. planBackend correctly routes around
    // an unavailable hardware path via hasHardware = false.
    if (hw.analyze.blocked_reason) {
      console.warn(
        `[analyze] hardware analyze currently blocked (planBackend will route to Gemini if available): ${hw.analyze.blocked_reason}`,
      );
    }
    const hasHardware = !!hw.analyze.url;
    const quota = await getTierQuotas();
    const preference =
      cfg.relay_analyze_backend_preference || "gemini_first";
    const plan = planBackend(row, quota, { hasHardware, preference });
    if (!plan.allowed) {
      await recordCall({
        install_id: auditInstall,
        license_fingerprint: licenseFp,
        tier,
        pipeline: "analyze",
        backend: null,
        model: null,
        status: "refused",
        credit_charged: 0,
        duration_ms: Date.now() - t0,
        cost_usd: 0,
        job_id: jobId,
        error: plan.reason,
      });
      const e = await errorEnvelope({
        error: plan.reason,
        creditKey,
        installId,
        tier,
        statusHint: 402,
      });
      return res.status(402).json(e.body);
    }
    const chosenBackend = plan.backend;

    let result;
    try {
      if (chosenBackend === "gemini") {
        const backend = createGeminiBackend({
          apiKey: cfg.relay_gemini_api_key,
          transcriptionModel: cfg.relay_gemini_transcription_model,
          analysisModel: cfg.relay_gemini_analysis_model,
        });
        result = await backend.analyzeText({ prompt });
      } else {
        const backend = createHardwareBackend({
          parakeetBaseURL: hw.transcribe.url || "",
          gemmaBaseURL: hw.analyze.url || "",
          sparkControlBaseURL: hw.sparkBase || "",
          parakeetModel: hw.transcribe.model || "",
          gemmaModel: hw.analyze.model || "",
        });
        result = await backend.analyzeText({ prompt });
      }
    } catch (err) {
      if (reusedJob) await refundJob({ creditKey, installId, license, jobId });
      console.error(`[relay/analyze] backend error: ${err?.message}`);
      // Passive health-event report to Spark Control so the
      // operator's dashboard surfaces the failure immediately
      // (without waiting for its own polling cycle to catch it).
      // Only fired for hardware-side calls — Gemini failures are a
      // separate observability surface (Google's API health).
      if (chosenBackend === "hardware") {
        reportHealthEvent({
          service: "vllm",
          ok: false,
          error: (err?.message || String(err)).slice(0, 280),
          ms: Date.now() - t0,
        });
      }
      await recordCall({
        install_id: auditInstall,
        license_fingerprint: licenseFp,
        tier,
        pipeline: "analyze",
        backend: chosenBackend,
        model: chosenBackend === "gemini"
          ? cfg.relay_gemini_analysis_model
          : hw.analyze.model || "(auto)",
        status: "error",
        credit_charged: 0,
        duration_ms: Date.now() - t0,
        cost_usd: 0,
        job_id: jobId,
        error: (err?.message || String(err)).slice(0, 200),
      });
      const e = await errorEnvelope({
        error: err?.message || "backend_error",
        creditKey,
        installId,
        tier,
        statusHint: err?.status || 502,
      });
      return res.status(e.statusHint).json(e.body);
    }

    let creditCharged = 0;
    if (!reusedJob) {
      await commitCredit({ creditKey, installId, license, backend: chosenBackend, tier });
      await markJobCharged({ creditKey, installId, license, jobId, backend: chosenBackend, tier });
      creditCharged = 1;
    }

    const costDetails =
      chosenBackend === "gemini" && result.usage
        ? calcGeminiCost(result.model, result.usage)
        : {
            input_tokens: 0,
            output_tokens: 0,
            thinking_tokens: 0,
            cost_usd: 0,
          };
    await recordCall({
      install_id: auditInstall,
      license_fingerprint: licenseFp,
      tier,
      pipeline: "analyze",
      backend: chosenBackend,
      model: result?.model || null,
      status: "success",
      credit_charged: creditCharged,
      duration_ms: Date.now() - t0,
      job_id: jobId,
      // Surface the cascade so the dashboard can show "served by
      // 2.5-flash after 3-flash 503'd" — Gemini backend returns this;
      // hardware backend doesn't (no per-model fallback there).
      attempts: result?.attempts || null,
      ...costDetails,
    });

    const body = await envelope({ result, creditKey, installId, license, tier, creditCharged });
    res.json(body);
  });

  return router;
}