stack/apps/web/src/lib/api/telemetry.ts

/**
 * Telemetry API Client
 * Handles telemetry data fetching for the usage dashboard.
 *
 * NOTE: Currently returns mock/placeholder data since the telemetry API
 * aggregation endpoints don't exist yet. The important thing is the UI structure.
 * When the backend endpoints are ready, replace mock calls with real apiGet() calls.
 */

import { apiGet, type ApiResponse } from "./client";

// ─── Types ───────────────────────────────────────────────────────────

export type TimeRange = "7d" | "30d" | "90d";

export interface UsageSummary {
  totalTokens: number;
  totalCost: number;
  taskCount: number;
  avgQualityGatePassRate: number;
}

export interface TokenUsagePoint {
  date: string;
  inputTokens: number;
  outputTokens: number;
  totalTokens: number;
}

export interface CostBreakdownItem {
  model: string;
  provider: string;
  cost: number;
  taskCount: number;
}

export interface TaskOutcomeItem {
  outcome: string;
  count: number;
  color: string;
}

export interface EstimateParams {
  taskType: string;
  model: string;
  provider: string;
  complexity: string;
}

export interface EstimateResponse {
  prediction: {
    input_tokens: { median: number; p75: number; p90: number };
    output_tokens: { median: number; p75: number; p90: number };
    cost_usd_micros: Record<string, number>;
    quality: { gate_pass_rate: number; success_rate: number };
  } | null;
  metadata: {
    sample_size: number;
    confidence: "none" | "low" | "medium" | "high";
  };
}

// ─── Mock Data Generators ────────────────────────────────────────────

function generateDateRange(range: TimeRange): string[] {
  const days = range === "7d" ? 7 : range === "30d" ? 30 : 90;
  const dates: string[] = [];
  const now = new Date();

  for (let i = days - 1; i >= 0; i--) {
    const d = new Date(now);
    d.setDate(d.getDate() - i);
    dates.push(d.toISOString().split("T")[0] ?? "");
  }

  return dates;
}

function generateMockTokenUsage(range: TimeRange): TokenUsagePoint[] {
  const dates = generateDateRange(range);

  return dates.map((date) => {
    const baseInput = 8000 + Math.floor(Math.random() * 12000);
    const baseOutput = 3000 + Math.floor(Math.random() * 7000);
    return {
      date,
      inputTokens: baseInput,
      outputTokens: baseOutput,
      totalTokens: baseInput + baseOutput,
    };
  });
}

function generateMockSummary(range: TimeRange): UsageSummary {
  const multiplier = range === "7d" ? 1 : range === "30d" ? 4 : 12;
  return {
    totalTokens: 245_800 * multiplier,
    totalCost: 3.42 * multiplier,
    taskCount: 47 * multiplier,
    avgQualityGatePassRate: 0.87,
  };
}

function generateMockCostBreakdown(): CostBreakdownItem[] {
  return [
    { model: "claude-sonnet-4-5", provider: "anthropic", cost: 18.5, taskCount: 124 },
    { model: "gpt-4o", provider: "openai", cost: 12.3, taskCount: 89 },
    { model: "claude-haiku-3.5", provider: "anthropic", cost: 4.2, taskCount: 156 },
    { model: "llama-3.3-70b", provider: "ollama", cost: 0, taskCount: 67 },
    { model: "gemini-2.0-flash", provider: "google", cost: 2.8, taskCount: 42 },
  ];
}

// PDA-friendly colors: calm, no aggressive reds
function generateMockTaskOutcomes(): TaskOutcomeItem[] {
  return [
    { outcome: "Success", count: 312, color: "#6EBF8B" },
    { outcome: "Partial", count: 48, color: "#F5C862" },
    { outcome: "Timeout", count: 18, color: "#94A3B8" },
    { outcome: "Incomplete", count: 22, color: "#C4A5DE" },
  ];
}

// ─── API Functions ───────────────────────────────────────────────────

/**
 * Fetch usage summary data (total tokens, cost, task count, quality rate)
 */
export async function fetchUsageSummary(timeRange: TimeRange): Promise<UsageSummary> {
  // TODO: Replace with real API call when backend aggregation endpoints are ready
  // const response = await apiGet<ApiResponse<UsageSummary>>(`/api/telemetry/summary?range=${timeRange}`);
  // return response.data;
  void apiGet; // suppress unused import warning in the meantime
  await new Promise((resolve) => setTimeout(resolve, 200));
  return generateMockSummary(timeRange);
}

/**
 * Fetch token usage time series for charts
 */
export async function fetchTokenUsage(timeRange: TimeRange): Promise<TokenUsagePoint[]> {
  // TODO: Replace with real API call
  // const response = await apiGet<ApiResponse<TokenUsagePoint[]>>(`/api/telemetry/tokens?range=${timeRange}`);
  // return response.data;
  await new Promise((resolve) => setTimeout(resolve, 250));
  return generateMockTokenUsage(timeRange);
}

/**
 * Fetch cost breakdown by model
 */
export async function fetchCostBreakdown(timeRange: TimeRange): Promise<CostBreakdownItem[]> {
  // TODO: Replace with real API call
  // const response = await apiGet<ApiResponse<CostBreakdownItem[]>>(`/api/telemetry/costs?range=${timeRange}`);
  // return response.data;
  await new Promise((resolve) => setTimeout(resolve, 200));
  void timeRange;
  return generateMockCostBreakdown();
}

/**
 * Fetch task outcome distribution
 */
export async function fetchTaskOutcomes(timeRange: TimeRange): Promise<TaskOutcomeItem[]> {
  // TODO: Replace with real API call
  // const response = await apiGet<ApiResponse<TaskOutcomeItem[]>>(`/api/telemetry/outcomes?range=${timeRange}`);
  // return response.data;
  await new Promise((resolve) => setTimeout(resolve, 150));
  void timeRange;
  return generateMockTaskOutcomes();
}

/**
 * Fetch cost/token estimate for a given task configuration.
 * Uses the real GET /api/telemetry/estimate endpoint from TEL-006.
 */
export async function fetchEstimate(params: EstimateParams): Promise<EstimateResponse> {
  const query = new URLSearchParams({
    taskType: params.taskType,
    model: params.model,
    provider: params.provider,
    complexity: params.complexity,
  }).toString();

  const response = await apiGet<ApiResponse<EstimateResponse>>(`/api/telemetry/estimate?${query}`);
  return response.data;
}