OmniRoute/src/lib/modelMetadataRegistry.ts

import { randomUUID } from "node:crypto";
import { parseModel } from "@omniroute/open-sse/services/model.ts";
import { getModelInfo } from "@/sse/services/model";
import { getModelAliases } from "@/lib/db/models";
import {
  getResolvedModelCapabilities,
  getResolvedModelContextOverride,
  isNonChatCatalogSurface,
} from "@/lib/modelCapabilities";
import {
  getAuthoritativeContextWindow,
  getAuthoritativeProviderContextWindow,
  getModelSpec,
  resolveModelAlias as resolveStaticModelAlias,
} from "@/shared/constants/modelSpecs";
import { AI_PROVIDERS } from "@/shared/constants/providers";
import { PROVIDER_ID_TO_ALIAS, PROVIDER_MODELS } from "@/shared/constants/models";
import { getSyncStatus, getSyncedCapability, getModelsDevPricing } from "@/lib/modelsDevSync";
import { getSyncedPricing } from "@/lib/pricingSync";
import { getPricingForModel as getDefaultPricingForModel } from "@/shared/constants/pricing";
import {
  CANONICAL_EFFORT_VALUES,
  extendCodexGpt56EffortValues,
} from "@/shared/reasoning/effortStandardization";

const MODEL_METADATA_SCHEMA_VERSION = "model-metadata-v1";

export const MODEL_ALIAS_AMBIGUOUS = "MODEL_ALIAS_AMBIGUOUS";
export const MODEL_NOT_MAPPED = "MODEL_NOT_MAPPED";
export const INTERNAL_PROXY_ERROR = "INTERNAL_PROXY_ERROR";

type JsonRecord = Record<string, unknown>;

interface CatalogDiagnosticsOptions {
  request?: Request | null;
  requestId?: string | null;
  resolvedAlias?: string | null;
}

export interface CanonicalModelMetadata {
  provider: string | null;
  providerAlias: string | null;
  providerLabel: string | null;
  model: string;
  qualifiedId: string | null;
  displayName: string;
  aliases: string[];
  capabilities: {
    toolCalling: boolean;
    reasoning: boolean;
    supportsThinking: boolean | null;
    supportsTools: boolean | null;
    vision: boolean | null;
    attachment: boolean | null;
    structuredOutput: boolean | null;
    temperature: boolean | null;
  };
  limits: {
    contextWindow: number | null;
    maxInputTokens: number | null;
    maxOutputTokens: number;
    defaultThinkingBudget: number;
    thinkingBudgetCap: number | null;
    thinkingOverhead: number | null;
    adaptiveMaxTokens: number | null;
  };
  metadata: {
    family: string | null;
    status: string | null;
    knowledgeCutoff: string | null;
    releaseDate: string | null;
    lastUpdated: string | null;
    openWeights: boolean | null;
    source: {
      providerRegistry: boolean;
      staticSpec: boolean;
      syncedCapability: boolean;
    };
  };
  modalities: {
    input: string[];
    output: string[];
    interleavedField: string | null;
  };
}

export interface ResolvedAliasLookup {
  alias: string;
  resolvedAlias: string;
  source: "stored_alias" | "direct_model" | "catalog_match";
  provider: string;
  providerAlias: string;
  model: string;
  target: unknown;
  metadata: CanonicalModelMetadata;
}

export interface AliasResolutionError {
  status: number;
  code: string;
  message: string;
  candidates?: string[];
}

function asNonEmptyString(value: unknown): string | null {
  return typeof value === "string" && value.trim().length > 0 ? value.trim() : null;
}

function uniqueStrings(values: Array<string | null | undefined>) {
  return [
    ...new Set(values.filter((value): value is string => Boolean(value && value.length > 0))),
  ];
}

function toQualifiedId(
  providerAlias: string | null,
  provider: string | null,
  model: string | null
) {
  if (!model) return null;
  if (providerAlias) return `${providerAlias}/${model}`;
  if (provider) return `${provider}/${model}`;
  return model;
}

function getRegistryModel(providerOrAlias: string | null, modelId: string | null) {
  if (!providerOrAlias || !modelId) return null;
  const alias = PROVIDER_ID_TO_ALIAS[providerOrAlias] || providerOrAlias;
  const models = PROVIDER_MODELS[alias] || PROVIDER_MODELS[providerOrAlias] || [];
  return models.find((entry) => entry?.id === modelId) || null;
}

function buildModalities(
  input: string[],
  output: string[],
  supportsVision: boolean | null
): { input: string[]; output: string[] } {
  if (input.length > 0 || output.length > 0) {
    return { input, output };
  }
  if (supportsVision) {
    return { input: ["text", "image"], output: ["text"] };
  }
  return { input: [], output: [] };
}

function extractCandidateMatches(modelId: string) {
  const matches: Array<{ provider: string; providerAlias: string; model: string }> = [];
  for (const [providerAlias, models] of Object.entries(PROVIDER_MODELS)) {
    for (const entry of models || []) {
      if (entry?.id !== modelId) continue;
      const providerId =
        Object.entries(PROVIDER_ID_TO_ALIAS).find(([, alias]) => alias === providerAlias)?.[0] ||
        providerAlias;
      matches.push({
        provider: providerId,
        providerAlias: PROVIDER_ID_TO_ALIAS[providerId] || providerAlias,
        model: entry.id,
      });
    }
  }
  return matches;
}

function getResolvedRequestId(request?: Request | null, requestId?: string | null) {
  const incomingId =
    asNonEmptyString(requestId) || asNonEmptyString(request?.headers.get("x-request-id"));
  return incomingId || randomUUID();
}

export function getModelCatalogVersion() {
  const syncStatus = getSyncStatus();
  return syncStatus.lastSync
    ? `${MODEL_METADATA_SCHEMA_VERSION}:${syncStatus.lastSync}`
    : `${MODEL_METADATA_SCHEMA_VERSION}:static`;
}

export function getCatalogDiagnosticsHeaders(
  options: CatalogDiagnosticsOptions = {}
): Record<string, string> {
  const resolvedRequestId = getResolvedRequestId(options.request, options.requestId);
  return {
    "X-Request-Id": resolvedRequestId,
    "X-Model-Catalog-Version": getModelCatalogVersion(),
    ...(options.resolvedAlias ? { "X-Model-Alias-Resolved": options.resolvedAlias } : {}),
  };
}

export function getCanonicalModelMetadata(input: {
  provider?: string | null;
  model?: string | null;
}): CanonicalModelMetadata | null {
  const modelId = asNonEmptyString(input.model);
  if (!modelId) return null;

  const resolved = getResolvedModelCapabilities({
    provider: input.provider || null,
    model: modelId,
  });
  const provider = resolved.provider;
  const providerAlias = provider ? PROVIDER_ID_TO_ALIAS[provider] || provider : null;
  const registryModel = getRegistryModel(providerAlias || provider, resolved.model || modelId);
  const staticSpec = getModelSpec(resolved.model || modelId);
  const syncedCapability =
    provider && resolved.model ? getSyncedCapability(provider, resolved.model) : null;
  const canonicalStaticAlias = resolveStaticModelAlias(resolved.model || modelId);
  const modalities = buildModalities(
    resolved.modalitiesInput,
    resolved.modalitiesOutput,
    resolved.supportsVision
  );

  return {
    provider,
    providerAlias,
    providerLabel:
      (provider && (AI_PROVIDERS as Record<string, JsonRecord>)[provider]?.name?.toString()) ||
      null,
    model: resolved.model || modelId,
    qualifiedId: toQualifiedId(providerAlias, provider, resolved.model || modelId),
    displayName: registryModel?.name || resolved.model || modelId,
    aliases: uniqueStrings([
      canonicalStaticAlias !== (resolved.model || modelId) ? canonicalStaticAlias : null,
      ...(staticSpec?.aliases || []),
    ]),
    capabilities: {
      toolCalling: resolved.toolCalling,
      reasoning: resolved.reasoning,
      supportsThinking: resolved.supportsThinking,
      supportsTools: resolved.supportsTools,
      vision: resolved.supportsVision,
      attachment: resolved.attachment,
      structuredOutput: resolved.structuredOutput,
      temperature: resolved.temperature,
    },
    limits: {
      contextWindow: resolved.contextWindow,
      maxInputTokens: resolved.maxInputTokens,
      maxOutputTokens: resolved.maxOutputTokens,
      defaultThinkingBudget: resolved.defaultThinkingBudget,
      thinkingBudgetCap: resolved.thinkingBudgetCap,
      thinkingOverhead: resolved.thinkingOverhead,
      adaptiveMaxTokens: resolved.adaptiveMaxTokens,
    },
    metadata: {
      family: resolved.family,
      status: resolved.status,
      knowledgeCutoff: resolved.knowledgeCutoff,
      releaseDate: resolved.releaseDate,
      lastUpdated: resolved.lastUpdated,
      openWeights: resolved.openWeights,
      source: {
        providerRegistry: Boolean(registryModel),
        staticSpec: Boolean(staticSpec),
        syncedCapability: Boolean(syncedCapability),
      },
    },
    modalities: {
      input: modalities.input,
      output: modalities.output,
      interleavedField: resolved.interleavedField,
    },
  };
}

// #8697 second bottleneck (after getModelsDevPricing memoization above): findInsensitive
// rebuilt a full Object.entries() scan on every miss, twice per model (provider lookup +
// model lookup) — ~6091 models × ~180-210 entries ≈ 1.2-1.3M allocations per catalog
// rebuild. Replaced with a lowercase-key index built once per distinct object and cached
// by identity (WeakMap) — getModelsDevPricing() returns the same object reference while
// its cache is warm, so the index is reused across every resolveCatalogPricing() call in
// a rebuild instead of rebuilt per lookup.
const lowercaseIndexCache = new WeakMap<object, Map<string, unknown>>();

function findInsensitive<T>(obj: Record<string, T> | null | undefined, key: string): T | undefined {
  if (!obj || !key) return undefined;
  if (key in obj) return obj[key];
  let index = lowercaseIndexCache.get(obj);
  if (!index) {
    index = new Map();
    for (const [k, v] of Object.entries(obj)) {
      const lowerKey = k.toLowerCase();
      // Warn once at index-build time (not per-lookup) if two keys collide
      // case-insensitively — a real data-quality signal from an upstream sync (e.g.
      // models.dev returning both "OpenAI" and "openai" as distinct provider keys).
      // Matches the pre-fix scan's silent first-match-wins behavior, just surfaced
      // instead of swallowed.
      if (index.has(lowerKey)) {
        console.warn(
          `[modelMetadataRegistry] findInsensitive: case-insensitive key collision on "${lowerKey}" — keeping first-seen value, later one discarded`
        );
        continue;
      }
      index.set(lowerKey, v);
    }
    lowercaseIndexCache.set(obj, index);
  }
  return index.get(key.toLowerCase()) as T | undefined;
}

function resolveCatalogPricing(
  provider: string | null,
  model: string | null
): Record<string, number> | null {
  if (!provider || !model) return null;

  // Prefer models.dev synced pricing when present; fall back to hardcoded defaults.
  try {
    const modelsDev = getModelsDevPricing() as Record<
      string,
      Record<string, Record<string, number>>
    >;
    const providerPricing =
      findInsensitive(modelsDev, provider) ||
      findInsensitive(modelsDev, provider.replace(/-cn$/, ""));
    if (providerPricing) {
      const modelPricing =
        findInsensitive(providerPricing, model) ||
        findInsensitive(providerPricing, model.replace(/\./g, "-")) ||
        findInsensitive(
          providerPricing,
          model.includes("/") ? model.split("/").pop() || model : model
        );
      if (modelPricing && typeof modelPricing === "object") {
        const input = modelPricing.input;
        const output = modelPricing.output;
        if (typeof input === "number" || typeof output === "number") {
          const pricing: Record<string, number> = {};
          if (typeof input === "number") pricing.input = input;
          if (typeof output === "number") pricing.output = output;
          if (typeof modelPricing.cached === "number") pricing.cached = modelPricing.cached;
          if (typeof modelPricing.cache_creation === "number") {
            pricing.cache_creation = modelPricing.cache_creation;
          }
          return pricing;
        }
      }
    }
  } catch {
    // pricing lookup must never break catalog assembly
  }

  // LiteLLM-synced pricing (`pricing_synced` namespace) — Layer 3 in the
  // documented resolution order (user > models.dev > LiteLLM > defaults).
  // Consulted only when models.dev returned nothing, matching the order
  // already implemented in db/settings/pricing.ts::getPricing().
  try {
    const litellm = getSyncedPricing() as Record<string, Record<string, Record<string, number>>>;
    const providerPricing =
      findInsensitive(litellm, provider) || findInsensitive(litellm, provider.replace(/-cn$/, ""));
    if (providerPricing) {
      const modelPricing =
        findInsensitive(providerPricing, model) ||
        findInsensitive(providerPricing, model.replace(/\./g, "-")) ||
        findInsensitive(
          providerPricing,
          model.includes("/") ? model.split("/").pop() || model : model
        );
      if (modelPricing && typeof modelPricing === "object") {
        const input = modelPricing.input;
        const output = modelPricing.output;
        if (typeof input === "number" || typeof output === "number") {
          const pricing: Record<string, number> = {};
          if (typeof input === "number") pricing.input = input;
          if (typeof output === "number") pricing.output = output;
          if (typeof modelPricing.cached === "number") pricing.cached = modelPricing.cached;
          if (typeof modelPricing.cache_creation === "number") {
            pricing.cache_creation = modelPricing.cache_creation;
          }
          return pricing;
        }
      }
    }
  } catch {
    // pricing lookup must never break catalog assembly
  }

  try {
    const defaults = getDefaultPricingForModel(provider, model) as Record<string, number> | null;
    if (defaults && (typeof defaults.input === "number" || typeof defaults.output === "number")) {
      return defaults;
    }
  } catch {
    // ignore
  }
  return null;
}

export function enrichCatalogModelEntry<T extends JsonRecord>(
  entry: T,
  input?: { provider?: string | null; model?: string | null }
): T {
  const provider =
    input?.provider ||
    (typeof entry.owned_by === "string" && entry.owned_by !== "combo" ? entry.owned_by : null);
  const model =
    input?.model ||
    asNonEmptyString(entry.root) ||
    (() => {
      const id = asNonEmptyString(entry.id);
      if (!id) return null;
      if (id.includes("/")) return id.slice(id.indexOf("/") + 1);
      return id;
    })();

  const metadata = getCanonicalModelMetadata({ provider, model });
  if (!metadata) return entry;
  const registryModel = getRegistryModel(
    metadata.providerAlias || metadata.provider,
    metadata.model
  );

  const nextEntry: JsonRecord = { ...entry };
  const existingName = asNonEmptyString(entry.name);
  const authoritativeContextWindow =
    getAuthoritativeProviderContextWindow(metadata.provider, metadata.model) ??
    getAuthoritativeProviderContextWindow(provider, model) ??
    getAuthoritativeContextWindow(metadata.model) ??
    getAuthoritativeContextWindow(model);
  const specialtySurface = isNonChatCatalogSurface(entry.type);
  const persistedContextWindow = getResolvedModelContextOverride({ provider, model });
  const capabilityFields = {
    ...(typeof metadata.capabilities.vision === "boolean"
      ? { vision: metadata.capabilities.vision }
      : {}),
    // #8016: never invent chat tool/reasoning defaults onto specialty surfaces.
    // Only copy boolean true when authoritative metadata says so; specialty rows
    // default to false instead of optimistic chat heuristics.
    tool_calling: specialtySurface
      ? metadata.capabilities.supportsTools === true || metadata.capabilities.toolCalling === true
        ? true
        : false
      : metadata.capabilities.toolCalling,
    reasoning: specialtySurface
      ? metadata.capabilities.supportsThinking === true || metadata.capabilities.reasoning === true
        ? true
        : false
      : metadata.capabilities.reasoning,
    // #6241: surface thinking support + the canonical effort tiers so the frontend can
    // render the effort/thinking toggles. `thinking` is kept for back-compat; `supportsThinking`
    // is the explicit flag and `effort_tiers` lists the selectable reasoning levels
    // (only when the model actually supports thinking).
    ...(typeof metadata.capabilities.supportsThinking === "boolean"
      ? {
          thinking: metadata.capabilities.supportsThinking,
          supportsThinking: metadata.capabilities.supportsThinking,
          ...(metadata.capabilities.supportsThinking
            ? {
                effort_tiers:
                  registryModel?.supportedThinkingEfforts &&
                  registryModel.supportedThinkingEfforts.length > 0
                    ? [...registryModel.supportedThinkingEfforts]
                    : extendCodexGpt56EffortValues(
                        metadata.provider,
                        metadata.model,
                        CANONICAL_EFFORT_VALUES
                      ),
              }
            : {}),
        }
      : {}),
    ...(typeof metadata.capabilities.attachment === "boolean"
      ? { attachment: metadata.capabilities.attachment }
      : {}),
    ...(typeof metadata.capabilities.structuredOutput === "boolean"
      ? { structured_output: metadata.capabilities.structuredOutput }
      : {}),
    ...(typeof metadata.capabilities.temperature === "boolean"
      ? { temperature: metadata.capabilities.temperature }
      : {}),
  };

  nextEntry.capabilities = {
    ...(entry.capabilities && typeof entry.capabilities === "object"
      ? (entry.capabilities as JsonRecord)
      : {}),
    ...capabilityFields,
  };

  if (!Array.isArray(entry.input_modalities) && metadata.modalities.input.length > 0) {
    nextEntry.input_modalities = metadata.modalities.input;
  }

  if (!Array.isArray(entry.output_modalities) && metadata.modalities.output.length > 0) {
    nextEntry.output_modalities = metadata.modalities.output;
  }

  if (
    !specialtySurface &&
    (typeof nextEntry.context_length !== "number" ||
      authoritativeContextWindow !== null ||
      persistedContextWindow !== null) &&
    typeof metadata.limits.contextWindow === "number"
  ) {
    nextEntry.context_length = metadata.limits.contextWindow;
  } else if (specialtySurface && persistedContextWindow !== null) {
    // Exact persisted overrides are authoritative for every surface of the model.
    nextEntry.context_length = persistedContextWindow;
  } else if (
    specialtySurface &&
    authoritativeContextWindow !== null &&
    typeof authoritativeContextWindow === "number"
  ) {
    // Only authoritative static windows may otherwise decorate specialty rows.
    nextEntry.context_length = authoritativeContextWindow;
  } else if (specialtySurface && typeof nextEntry.context_length === "number") {
    // Keep an explicit source-provided context if the emitter already set one.
  } else if (specialtySurface) {
    delete nextEntry.context_length;
  }

  if (typeof metadata.limits.maxOutputTokens === "number" && metadata.limits.maxOutputTokens > 0) {
    nextEntry.max_output_tokens = metadata.limits.maxOutputTokens;
  }

  if (
    typeof metadata.limits.maxInputTokens === "number" &&
    (typeof nextEntry.max_input_tokens !== "number" || authoritativeContextWindow !== null)
  ) {
    nextEntry.max_input_tokens = metadata.limits.maxInputTokens;
  }

  if (metadata.metadata.family) nextEntry.family = metadata.metadata.family;
  if (metadata.metadata.status) nextEntry.status = metadata.metadata.status;
  if (metadata.metadata.knowledgeCutoff)
    nextEntry.knowledge_cutoff = metadata.metadata.knowledgeCutoff;
  if (metadata.metadata.releaseDate) nextEntry.release_date = metadata.metadata.releaseDate;
  if (metadata.metadata.lastUpdated) nextEntry.last_updated = metadata.metadata.lastUpdated;
  if (typeof metadata.metadata.openWeights === "boolean") {
    nextEntry.open_weights = metadata.metadata.openWeights;
  }
  if (!existingName && metadata.displayName) {
    nextEntry.name = metadata.displayName;
  }

  if (nextEntry.pricing == null) {
    const pricing = resolveCatalogPricing(provider, model);
    if (pricing) nextEntry.pricing = pricing;
  }

  return nextEntry as T;
}

function buildAliasCandidates(alias: string) {
  const parsed = parseModel(alias);
  const modelId = asNonEmptyString(parsed.model) || asNonEmptyString(alias);
  if (!modelId) return [];
  const canonicalModel = resolveStaticModelAlias(modelId);
  const candidateModelIds = uniqueStrings([modelId, canonicalModel]);
  const candidates = new Map<string, { provider: string; providerAlias: string; model: string }>();

  for (const candidateModelId of candidateModelIds) {
    for (const match of extractCandidateMatches(candidateModelId)) {
      candidates.set(`${match.provider}/${match.model}`, match);
    }
  }

  return [...candidates.values()];
}

function normalizeAliasCandidates(candidates: string[] | undefined) {
  return uniqueStrings(
    (candidates || []).map((candidate) => {
      const parsed = parseModel(candidate);
      if (!parsed.provider || !parsed.model) return candidate;
      const providerAlias = PROVIDER_ID_TO_ALIAS[parsed.provider] || parsed.provider;
      return `${providerAlias}/${parsed.model}`;
    })
  );
}

export async function resolveModelAliasLookup(
  alias: string
): Promise<{ ok: true; value: ResolvedAliasLookup } | { ok: false; error: AliasResolutionError }> {
  const normalizedAlias = asNonEmptyString(alias);
  if (!normalizedAlias) {
    return {
      ok: false,
      error: {
        status: 400,
        code: MODEL_NOT_MAPPED,
        message: "Alias is required",
      },
    };
  }

  const aliases = await getModelAliases();
  const explicitTarget = aliases[normalizedAlias];

  if (explicitTarget !== undefined) {
    const modelInfo = await getModelInfo(normalizedAlias);
    if (!modelInfo.provider || !modelInfo.model) {
      const candidates = normalizeAliasCandidates(
        (modelInfo as JsonRecord).candidateAliases as string[]
      );
      return {
        ok: false,
        error: {
          status: 409,
          code: MODEL_ALIAS_AMBIGUOUS,
          message:
            (modelInfo as JsonRecord).errorMessage?.toString() ||
            `Alias '${normalizedAlias}' is ambiguous.`,
          ...(candidates.length > 0 ? { candidates } : {}),
        },
      };
    }

    const providerAlias = PROVIDER_ID_TO_ALIAS[modelInfo.provider] || modelInfo.provider;
    return {
      ok: true,
      value: {
        alias: normalizedAlias,
        resolvedAlias: `${providerAlias}/${modelInfo.model}`,
        source: "stored_alias",
        provider: modelInfo.provider,
        providerAlias,
        model: modelInfo.model,
        target: explicitTarget,
        metadata: getCanonicalModelMetadata({
          provider: modelInfo.provider,
          model: modelInfo.model,
        })!,
      },
    };
  }

  const parsed = parseModel(normalizedAlias);
  if (parsed.provider && parsed.model) {
    const modelInfo = await getModelInfo(normalizedAlias);
    if (!modelInfo.provider || !modelInfo.model) {
      return {
        ok: false,
        error: {
          status: 404,
          code: MODEL_NOT_MAPPED,
          message: `Model '${normalizedAlias}' is not mapped.`,
        },
      };
    }

    const providerAlias = PROVIDER_ID_TO_ALIAS[modelInfo.provider] || modelInfo.provider;
    return {
      ok: true,
      value: {
        alias: normalizedAlias,
        resolvedAlias: `${providerAlias}/${modelInfo.model}`,
        source: "direct_model",
        provider: modelInfo.provider,
        providerAlias,
        model: modelInfo.model,
        target: `${providerAlias}/${modelInfo.model}`,
        metadata: getCanonicalModelMetadata({
          provider: modelInfo.provider,
          model: modelInfo.model,
        })!,
      },
    };
  }

  const candidates = buildAliasCandidates(normalizedAlias);
  if (candidates.length === 0) {
    return {
      ok: false,
      error: {
        status: 404,
        code: MODEL_NOT_MAPPED,
        message: `Alias '${normalizedAlias}' is not mapped.`,
      },
    };
  }

  if (candidates.length > 1) {
    return {
      ok: false,
      error: {
        status: 409,
        code: MODEL_ALIAS_AMBIGUOUS,
        message: `Alias '${normalizedAlias}' is ambiguous. Use provider/model prefix.`,
        candidates: candidates.map((candidate) => `${candidate.providerAlias}/${candidate.model}`),
      },
    };
  }

  const match = candidates[0];
  const metadata = getCanonicalModelMetadata({
    provider: match.provider,
    model: match.model,
  });

  return {
    ok: true,
    value: {
      alias: normalizedAlias,
      resolvedAlias: `${match.providerAlias}/${match.model}`,
      source: "catalog_match",
      provider: match.provider,
      providerAlias: match.providerAlias,
      model: match.model,
      target: `${match.providerAlias}/${match.model}`,
      metadata: metadata!,
    },
  };
}

/**
 * Qualify duplicate model display names with a provider prefix so users can
 * distinguish between providers that serve the same model.
 *
 * Problem: when multiple providers (e.g. `gh`, `cx`, `opencode-zen`) all serve
 * `gpt-5.5`, each catalog entry gets `name: "GPT-5.5"`. A client like OpenCode
 * that renders the `name` field (src/plugin.ts: `name: model.name || model.id`)
 * shows an identical "GPT-5.5" for every provider variant, giving the user no
 * way to know which provider they are selecting.
 *
 * Fix: make a single O(n) pass over the enriched catalog. For any base name that
 * appears on entries from two or more distinct providers, replace each entry's
 * `name` with `<providerPrefix>/<baseName>` (e.g. "gh/GPT-5.5", "cx/GPT-5.5").
 * Entries with a unique name are left untouched, preserving the clean display for
 * the common single-provider case. The provider prefix is the first segment of
 * the model id (e.g. `gh` from `gh/gpt-5.5`).
 *
 * The modification is purely cosmetic — it only affects the catalog `name` field
 * used for display. Model IDs, routing, and request parsing are unchanged.
 */
export function disambiguateCatalogModelNames<T extends JsonRecord>(models: T[]): T[] {
  // Count how many distinct provider prefixes use each display name.
  const nameToProviders = new Map<string, Set<string>>();
  for (const model of models) {
    const name = asNonEmptyString(model.name);
    if (!name) continue;
    const id = asNonEmptyString(model.id);
    const prefix = id && id.includes("/") ? id.slice(0, id.indexOf("/")) : null;
    if (!prefix) continue;
    const existing = nameToProviders.get(name) || new Set<string>();
    existing.add(prefix);
    nameToProviders.set(name, existing);
  }

  // Only rewrite names that are shared across 2+ providers.
  const ambiguous = new Set<string>();
  for (const [name, providers] of nameToProviders) {
    if (providers.size > 1) ambiguous.add(name);
  }
  if (ambiguous.size === 0) return models;

  return models.map((model) => {
    const name = asNonEmptyString(model.name);
    if (!name || !ambiguous.has(name)) return model;
    const id = asNonEmptyString(model.id);
    const prefix = id && id.includes("/") ? id.slice(0, id.indexOf("/")) : null;
    if (!prefix) return model;
    return { ...model, name: `${prefix}/${name}` };
  });
}