hapi/shared/src/cursorCliSku.ts

/** Renamed ACP wire bases → live Cursor CLI sku family (e.g. grok-4.5 → cursor-grok-4.5). */
const CURSOR_LEGACY_MODEL_BASE_ALIASES: Readonly<Record<string, string>> = {
    'grok-4.5': 'cursor-grok-4.5',
};

export function resolveCursorLegacyModelBase(baseId: string): string {
    const trimmed = baseId.trim();
    return CURSOR_LEGACY_MODEL_BASE_ALIASES[trimmed] ?? trimmed;
}

/** ACP parameterized wire ids use bracket params; CLI `agent --list-models` slugs do not. */
export function isCursorAcpWireModelId(modelId: string): boolean {
    const trimmed = modelId.trim();
    return trimmed === 'default[]' || trimmed.includes('[');
}

export function cursorModelBaseId(modelId: string): string {
    const trimmed = modelId.trim();
    const bracket = trimmed.indexOf('[');
    return bracket === -1 ? trimmed : trimmed.slice(0, bracket);
}

/** Longest-first suffixes from Cursor CLI sku ids (e.g. `gpt-5.5-high-fast` → `gpt-5.5`). */
const CLI_SKU_SUFFIXES = [
    '-extra-high-fast',
    '-extra-high',
    '-xhigh-fast',
    '-xhigh',
    '-high-fast',
    '-high',
    '-medium-fast',
    '-medium',
    '-low-fast',
    '-low',
    '-none-fast',
    '-none',
    '-thinking-high-fast',
    '-thinking-high',
    '-thinking',
    '-fast',
] as const;

export function cursorCliSkuBaseId(slug: string): string {
    const trimmed = slug.trim();
    if (!trimmed || isCursorAcpWireModelId(trimmed)) {
        return cursorModelBaseId(trimmed);
    }

    let base = trimmed;
    let changed = true;
    while (changed) {
        changed = false;
        for (const suffix of CLI_SKU_SUFFIXES) {
            if (base.endsWith(suffix)) {
                base = base.slice(0, -suffix.length);
                changed = true;
                break;
            }
        }
    }
    return base;
}

/**
 * CLI probe SKUs that carry effort/speed suffixes (e.g. `gpt-5.5-high-fast`).
 * Base-only slugs like `composer-2.5` are not variant SKUs.
 */
export function isCursorCliSkuVariantId(modelId: string): boolean {
    const trimmed = modelId.trim();
    if (!trimmed || isCursorAcpWireModelId(trimmed)) {
        return false;
    }
    return cursorCliSkuBaseId(trimmed) !== trimmed;
}

/**
 * Picker/catalog-eligible ACP model ids.
 * Accepts parameterized wires and bare non-default ACP bases (current Cursor ACP).
 * Rejects CLI effort/speed SKU slugs so they stay variant rows, not top-level bases.
 */
export function isCursorAcpCatalogModelId(modelId: string): boolean {
    const trimmed = modelId.trim();
    if (!trimmed) {
        return false;
    }
    const lower = trimmed.toLowerCase();
    if (lower === 'auto' || lower === 'default') {
        return false;
    }
    if (isCursorAcpWireModelId(trimmed)) {
        return true;
    }
    if (isCursorCliSkuVariantId(trimmed)) {
        return false;
    }
    return true;
}

export function parseCursorWireParams(modelId: string): Record<string, string> {
    const variant = modelId.includes('[') ? modelId.slice(modelId.indexOf('[') + 1).replace(/\]$/, '') : '';
    if (!variant) {
        return {};
    }

    const params: Record<string, string> = {};
    for (const part of variant.split(',')) {
        const segment = part.trim();
        if (!segment) continue;
        const eq = segment.indexOf('=');
        if (eq === -1) {
            params[segment] = 'true';
            continue;
        }
        params[segment.slice(0, eq).trim()] = segment.slice(eq + 1).trim();
    }
    return params;
}

function inferSkuParamHints(slug: string): Record<string, string> {
    const lower = slug.toLowerCase();
    const hints: Record<string, string> = {};

    if (lower.includes('extra-high') || lower.includes('xhigh')) {
        hints.reasoning = 'extra-high';
        hints.effort = 'xhigh';
    } else if (lower.includes('-high')) {
        hints.reasoning = 'high';
        hints.effort = 'high';
    } else if (lower.includes('-low')) {
        hints.reasoning = 'low';
        hints.effort = 'low';
    } else if (lower.includes('-medium')) {
        hints.reasoning = 'medium';
        hints.effort = 'medium';
    } else if (lower.includes('-none')) {
        hints.reasoning = 'none';
    }

    // Cursor CLI convention: `-fast` suffix means fast=true; absence means fast=false.
    // Without an explicit hint, base-only SKUs (e.g. `composer-2.5`) would tie-break to the
    // first wire and silently coerce to the fast variant.
    hints.fast = lower.includes('-fast') ? 'true' : 'false';

    if (lower.includes('thinking')) {
        hints.thinking = 'true';
    }

    return hints;
}

function scoreWireAgainstSku(slug: string, wireId: string): number {
    const hints = inferSkuParamHints(slug);
    const params = parseCursorWireParams(wireId);
    let score = 0;

    for (const [key, value] of Object.entries(hints)) {
        if (params[key] === value) {
            score += 2;
        } else if (params[key] !== undefined) {
            score -= 1;
        }
    }

    return score;
}

/** Best-matching CLI sku for highlighting when session state stores an ACP wire id. */
export function findBestCliSkuForAcpWire(
    wireId: string,
    skuIds: readonly string[]
): string | null {
    let best: string | null = null;
    let bestScore = Number.NEGATIVE_INFINITY;

    for (const sku of skuIds) {
        const trimmed = sku.trim();
        if (!trimmed || isCursorAcpWireModelId(trimmed)) {
            continue;
        }
        if (matchCliSkuToAcpWireId(trimmed, [{ modelId: wireId }]) !== wireId) {
            continue;
        }
        const score = scoreWireAgainstSku(trimmed, wireId);
        if (score > bestScore) {
            bestScore = score;
            best = trimmed;
        }
    }

    return best;
}

function syntheticSkuFromWireParams(base: string, params: Record<string, string>): string {
    const effort = params.reasoning ?? params.effort ?? 'medium';
    let sku = resolveCursorLegacyModelBase(base);

    if (effort === 'extra-high' || effort === 'xhigh') {
        sku += '-extra-high';
    } else if (effort === 'high') {
        sku += '-high';
    } else if (effort === 'low') {
        sku += '-low';
    } else if (effort === 'medium') {
        sku += '-medium';
    } else if (effort === 'none') {
        sku += '-none';
    }

    if (params.fast === 'true') {
        sku += '-fast';
    }

    return sku;
}

function pseudoWireFromSku(sku: string): string {
    const base = cursorCliSkuBaseId(sku);
    const hints = inferSkuParamHints(sku);
    const parts = Object.entries(hints).map(([key, value]) => `${key}=${value}`);
    return `${base}[${parts.join(',')}]`;
}

function pickBestCatalogSku(
    requestedSku: string,
    available: readonly { modelId: string }[]
): string | null {
    const skuBase = cursorCliSkuBaseId(requestedSku);
    const candidates = available.filter((entry) => {
        const modelId = entry.modelId.trim();
        return modelId && !isCursorAcpWireModelId(modelId) && cursorCliSkuBaseId(modelId) === skuBase;
    });
    if (candidates.length === 0) {
        return null;
    }
    if (candidates.length === 1) {
        return candidates[0].modelId;
    }

    const exact = candidates.find((entry) => entry.modelId === requestedSku);
    if (exact) {
        return exact.modelId;
    }

    const pseudoWire = pseudoWireFromSku(requestedSku);
    const requestedFast = inferSkuParamHints(requestedSku).fast;
    const sameSpeed = candidates.filter(
        (entry) => inferSkuParamHints(entry.modelId).fast === requestedFast
    );
    const rankedCandidates = sameSpeed.length > 0 ? sameSpeed : candidates;

    let best = rankedCandidates[0].modelId;
    let bestScore = Number.NEGATIVE_INFINITY;
    for (const entry of rankedCandidates) {
        const score = scoreWireAgainstSku(entry.modelId, pseudoWire);
        if (score > bestScore) {
            bestScore = score;
            best = entry.modelId;
        }
    }
    return best;
}

/** Parse model ids from Cursor `Cannot use this model` stderr (Available models: …). */
export function parseCursorAvailableModelsFromRejection(text: string): string[] {
    const match = text.match(/Available models:\s*([^\n]*)/i);
    if (!match) {
        return [];
    }

    let catalog = match[1].trim();
    const tipIdx = catalog.search(/\s+Tip:/i);
    if (tipIdx !== -1) {
        catalog = catalog.slice(0, tipIdx).trim();
    }

    return catalog
        .split(',')
        .map((part) => part.trim())
        .filter((part) => part.length > 0 && part.toLowerCase() !== 'auto');
}

function rewriteSkuBase(sku: string, fromBase: string, toBase: string): string {
    if (fromBase === toBase || !sku.startsWith(fromBase)) {
        return sku;
    }
    return `${toBase}${sku.slice(fromBase.length)}`;
}

/**
 * Prefer a `--model`-safe catalog id (bare base or CLI SKU) over an ACP wire.
 * Cursor rejects many bracketed wires on process start even when session/new
 * later exposes parameterized `currentModelId` wires.
 */
function preferSpawnSafeCatalogId(
    candidate: string,
    requestedWire: string,
    available: readonly { modelId: string }[]
): string {
    if (!isCursorAcpWireModelId(candidate)) {
        return candidate;
    }

    const wireBase = cursorModelBaseId(requestedWire);
    const legacyBase = resolveCursorLegacyModelBase(wireBase);
    const syntheticSku = rewriteSkuBase(
        syntheticSkuFromWireParams(wireBase, parseCursorWireParams(requestedWire)),
        wireBase,
        legacyBase
    );
    const fromSku = pickBestCatalogSku(syntheticSku, available);
    if (fromSku) {
        return fromSku;
    }

    for (const base of [legacyBase, wireBase]) {
        const bare = available.find(
            (entry) => entry.modelId === base && !isCursorAcpWireModelId(entry.modelId)
        );
        if (bare) {
            return bare.modelId;
        }
    }

    return candidate;
}

function pickBestCatalogWire(
    requestedWire: string,
    available: readonly { modelId: string }[]
): string | null {
    const wireBase = cursorModelBaseId(requestedWire);
    const legacyBase = resolveCursorLegacyModelBase(wireBase);
    const acceptedBases = new Set([wireBase, legacyBase]);
    const requestedParams = Object.entries(parseCursorWireParams(requestedWire));
    const wires = available.filter((entry) => {
        const modelId = entry.modelId.trim();
        if (
            !modelId
            || !isCursorAcpWireModelId(modelId)
            || !acceptedBases.has(resolveCursorLegacyModelBase(cursorModelBaseId(modelId)))
        ) {
            return false;
        }
        // Every explicit request param must be present on the candidate (do not
        // drop context/thinking/etc. via synthetic-SKU scoring alone).
        if (requestedParams.length === 0) {
            return true;
        }
        const candidateParams = parseCursorWireParams(modelId);
        return requestedParams.every(([key, value]) => candidateParams[key] === value);
    });
    if (wires.length === 0) {
        return null;
    }
    if (wires.length === 1) {
        return wires[0].modelId;
    }

    const syntheticSku = rewriteSkuBase(
        syntheticSkuFromWireParams(wireBase, parseCursorWireParams(requestedWire)),
        wireBase,
        legacyBase
    );
    let best = wires[0].modelId;
    let bestScore = Number.NEGATIVE_INFINITY;
    for (const entry of wires) {
        const score = scoreWireAgainstSku(syntheticSku, entry.modelId);
        if (score > bestScore) {
            bestScore = score;
            best = entry.modelId;
        }
    }
    return best;
}

/**
 * Remap a stale hub/ACP wire id onto a live Cursor catalog entry.
 * Returns null when no catalog candidate matches.
 */
export function remapStaleCursorModelId(
    requested: string,
    available: readonly { modelId: string }[]
): string | null {
    const trimmed = requested.trim();
    if (!trimmed) {
        return null;
    }

    const exact = available.find((entry) => entry.modelId === trimmed);
    const legacyWire = isCursorAcpWireModelId(trimmed)
        && resolveCursorLegacyModelBase(cursorModelBaseId(trimmed)) !== cursorModelBaseId(trimmed);
    if (exact && !legacyWire) {
        // Mixed caches often list the exact ACP wire *and* a CLI SKU. Prefer the
        // spawn-safe id so `agent --model` does not receive a rejected bracket wire.
        return isCursorAcpWireModelId(trimmed)
            ? preferSpawnSafeCatalogId(trimmed, trimmed, available)
            : trimmed;
    }

    if (isCursorAcpWireModelId(trimmed)) {
        const wireBase = cursorModelBaseId(trimmed);
        const legacyBase = resolveCursorLegacyModelBase(wireBase);
        const syntheticSku = rewriteSkuBase(
            syntheticSkuFromWireParams(wireBase, parseCursorWireParams(trimmed)),
            wireBase,
            legacyBase
        );

        // Prefer bare / CLI SKU rows (what `agent --model … acp` accepts).
        const fromSku = pickBestCatalogSku(syntheticSku, available);
        if (fromSku) {
            return fromSku;
        }

        for (const base of [legacyBase, wireBase]) {
            const bare = available.find(
                (entry) => entry.modelId === base && !isCursorAcpWireModelId(entry.modelId)
            );
            if (bare) {
                return bare.modelId;
            }
        }

        // Wire-only catalogs (session configOptions): nearest compatible same-base wire.
        // Do not fall through to SKU→wire matching — that drops explicit params like
        // thinking/context and can pick a contradictory variant.
        const fromWire = pickBestCatalogWire(trimmed, available);
        return fromWire ? preferSpawnSafeCatalogId(fromWire, trimmed, available) : null;
    }

    const legacyBase = resolveCursorLegacyModelBase(cursorCliSkuBaseId(trimmed));
    if (legacyBase !== cursorCliSkuBaseId(trimmed)) {
        const rewritten = trimmed.replace(cursorCliSkuBaseId(trimmed), legacyBase);
        return pickBestCatalogSku(rewritten, available)
            ?? matchCliSkuToAcpWireId(rewritten, available);
    }

    // Non-legacy, non-wire ids must remain exact; let Cursor report unavailability
    // instead of silently downgrading e.g. gpt-5.5-high-fast → gpt-5.5-medium.
    return null;
}

/**
 * Map UI/CLI model id (wire or slug) onto an ACP configOptions wire id.
 */
export function matchCliSkuToAcpWireId(
    requested: string,
    available: readonly { modelId: string }[]
): string | null {
    const trimmed = requested.trim();
    if (!trimmed) {
        return null;
    }

    const exact = available.find((entry) => entry.modelId === trimmed);
    if (exact) {
        return exact.modelId;
    }

    if (isCursorAcpWireModelId(trimmed)) {
        // Bracketed hub wires (including non-legacy) must remap onto live catalog rows.
        return remapStaleCursorModelId(trimmed, available);
    }

    const skuBase = cursorCliSkuBaseId(trimmed);
    const wires = available.filter(
        (entry) => isCursorAcpCatalogModelId(entry.modelId) && cursorModelBaseId(entry.modelId) === skuBase
    );
    if (wires.length === 0) {
        return null;
    }
    // Suffixed SKUs must not collapse onto a bare-only ACP catalog — those rows
    // cannot express effort/speed (apply is model + fast on parameterized wires).
    const hasParameterizedWire = wires.some((entry) => isCursorAcpWireModelId(entry.modelId));
    if (isCursorCliSkuVariantId(trimmed) && !hasParameterizedWire) {
        return null;
    }
    if (wires.length === 1) {
        return wires[0].modelId;
    }

    let best = wires[0].modelId;
    let bestScore = Number.NEGATIVE_INFINITY;
    for (const entry of wires) {
        const score = scoreWireAgainstSku(trimmed, entry.modelId);
        if (score > bestScore) {
            bestScore = score;
            best = entry.modelId;
        }
    }
    return best;
}