/** Pure measurement helpers for the benchmark suite. */
import { CanonMessage } from "../src/view";

const normalize = (s: string): string =>
  s.toLowerCase().replace(/\s+/g, " ").trim();

/** Case/whitespace-normalized substring match against accepted answers. */
export function gradeAnswer(response: string, accepted: string[]): boolean {
  const norm = normalize(response);
  return accepted.some((candidate) => norm.includes(normalize(candidate)));
}

export interface StructuralReport {
  singleLeadingSystem: boolean;
  noOrphanToolResults: boolean;
  hasUserMessage: boolean;
  ok: boolean;
}

/** Validate a compacted view: system text + tail messages. */
export function checkViewStructure(
  systemText: string | undefined,
  tail: CanonMessage[],
): StructuralReport {
  void systemText; // the system text lives outside the tail by construction
  const singleLeadingSystem = tail.every((m) => m.role !== "system");
  let noOrphanToolResults = true;
  tail.forEach((m, i) => {
    if (m.role !== "tool") return;
    const prev = tail[i - 1];
    const anchored =
      prev !== undefined &&
      (prev.role === "tool" ||
        (prev.role === "assistant" && (prev.toolCalls ?? []).length > 0));
    if (!anchored) noOrphanToolResults = false;
  });
  const hasUserMessage = tail.some((m) => m.role === "user");
  return {
    singleLeadingSystem,
    noOrphanToolResults,
    hasUserMessage,
    ok: singleLeadingSystem && noOrphanToolResults && hasUserMessage,
  };
}

export function reductionPercent(
  beforeTokens: number,
  afterTokens: number,
): number {
  if (beforeTokens <= 0) return 0;
  return Math.round((1 - afterTokens / beforeTokens) * 100);
}

export function latencyStats(samplesMs: number[]): {
  mean: number;
  p50: number;
  max: number;
} {
  if (samplesMs.length === 0) return { mean: 0, p50: 0, max: 0 };
  const sorted = [...samplesMs].sort((x, y) => x - y);
  const mean =
    Math.round(
      (sorted.reduce((total, v) => total + v, 0) / sorted.length) * 10,
    ) / 10;
  const p50 = sorted[Math.floor((sorted.length - 1) / 2)];
  const max = sorted[sorted.length - 1];
  return { mean, p50, max };
}

/** Pure measurement helpers for the benchmark suite. */
import { CanonMessage } from "../src/view";

const normalize = (s: string): string =>
  s.toLowerCase().replace(/\s+/g, " ").trim();

/** Case/whitespace-normalized substring match against accepted answers. */
export function gradeAnswer(response: string, accepted: string[]): boolean {
  const norm = normalize(response);
  return accepted.some((candidate) => norm.includes(normalize(candidate)));
}

export interface StructuralReport {
  singleLeadingSystem: boolean;
  noOrphanToolResults: boolean;
  hasUserMessage: boolean;
  ok: boolean;
}

/** Validate a compacted view: system text + tail messages. */
export function checkViewStructure(
  systemText: string | undefined,
  tail: CanonMessage[],
): StructuralReport {
  void systemText; // the system text lives outside the tail by construction
  const singleLeadingSystem = tail.every((m) => m.role !== "system");
  let noOrphanToolResults = true;
  tail.forEach((m, i) => {
    if (m.role !== "tool") return;
    const prev = tail[i - 1];
    const anchored =
      prev !== undefined &&
      (prev.role === "tool" ||
        (prev.role === "assistant" && (prev.toolCalls ?? []).length > 0));
    if (!anchored) noOrphanToolResults = false;
  });
  const hasUserMessage = tail.some((m) => m.role === "user");
  return {
    singleLeadingSystem,
    noOrphanToolResults,
    hasUserMessage,
    ok: singleLeadingSystem && noOrphanToolResults && hasUserMessage,
  };
}

export function reductionPercent(
  beforeTokens: number,
  afterTokens: number,
): number {
  if (beforeTokens <= 0) return 0;
  return Math.round((1 - afterTokens / beforeTokens) * 100);
}

export function latencyStats(samplesMs: number[]): {
  mean: number;
  p50: number;
  max: number;
} {
  if (samplesMs.length === 0) return { mean: 0, p50: 0, max: 0 };
  const sorted = [...samplesMs].sort((x, y) => x - y);
  const mean =
    Math.round(
      (sorted.reduce((total, v) => total + v, 0) / sorted.length) * 10,
    ) / 10;
  const p50 = sorted[Math.floor((sorted.length - 1) / 2)];
  const max = sorted[sorted.length - 1];
  return { mean, p50, max };
}