/**
 * PB-26-210: Release browser-gate validation.
 *
 * Pure functions that verify a gate result has no silent failures.
 * A release cannot report success with zero tests, unexpected skips,
 * flaky retries, or missing required projects.
 */

export interface ProjectResult {
  name: string;
  totalTests: number;
  passed: number;
  skipped: number;
  flaky: number;
}

export interface GateResult {
  projects: ProjectResult[];
}

export const REQUIRED_BROWSER_PROJECTS = ["chrome-release"] as const;

export interface PlaywrightJsonReport {
  suites?: Array<{
    title?: string;
    specs?: Array<{ tests?: Array<{ status?: string; results?: Array<{ status?: string }> }> }>;
    suites?: PlaywrightJsonReport["suites"];
  }>;
}

export function gateResultFromPlaywright(report: PlaywrightJsonReport): GateResult {
  const projects = new Map<string, ProjectResult>();
  const visit = (suites: PlaywrightJsonReport["suites"] = []) => {
    for (const suite of suites) {
      if (suite.title && REQUIRED_BROWSER_PROJECTS.includes(suite.title as (typeof REQUIRED_BROWSER_PROJECTS)[number])) {
        const project = projects.get(suite.title) ?? { name: suite.title, totalTests: 0, passed: 0, skipped: 0, flaky: 0 };
        for (const spec of suite.specs ?? []) for (const test of spec.tests ?? []) {
          project.totalTests++;
          const results = test.results ?? [];
          const status = results.at(-1)?.status ?? test.status;
          if (status === "skipped") project.skipped++;
          else if (status === "passed") project.passed++;
          if (results.length > 1 && results.some((result) => result.status === "passed")) project.flaky++;
        }
        projects.set(suite.title, project);
      }
      visit(suite.suites);
    }
  };
  visit(report.suites);
  return { projects: [...projects.values()] };
}

export function validatePlaywrightJsonReport(report: PlaywrightJsonReport): string[] {
  return validateGateResult(gateResultFromPlaywright(report));
}

export function formatGateErrors(errors: string[]): never {
  throw new Error(`Release browser gate validation failed:\n  ${errors.join("\n  ")}`);
}

export function assertValidPlaywrightJsonReport(report: PlaywrightJsonReport): void {
  const errors = validatePlaywrightJsonReport(report);
  if (errors.length > 0) formatGateErrors(errors);
}


/**
 * Validate a gate result. Returns a list of error strings — empty means pass.
 * The release gate fails (non-zero) on any error.
 */
export function validateGateResult(
  result: GateResult,
  requiredProjects: readonly string[] = REQUIRED_BROWSER_PROJECTS,
): string[] {
  const errors: string[] = [];

  const totalTests = result.projects.reduce((sum, p) => sum + p.totalTests, 0);
  if (totalTests === 0) {
    errors.push("zero tests discovered across all projects");
  }

  for (const name of requiredProjects) {
    const project = result.projects.find((p) => p.name === name);
    if (!project) {
      errors.push(`required project "${name}" is missing`);
      continue;
    }
    if (project.totalTests === 0) {
      errors.push(`project "${name}" has zero tests`);
    }
    if (project.skipped > 0) {
      errors.push(`project "${name}" has ${project.skipped} skipped test(s)`);
    }
    if (project.flaky > 0) {
      errors.push(`project "${name}" has ${project.flaky} flaky retry/retr(y)ies`);
    }
  }

  return errors;
}