import type { DoctorCheck, DoctorCheckId, DoctorReport, DoctorResult } from "./doctor.js";

interface DoctorSection {
  readonly checkIds: readonly DoctorCheckId[];
  readonly title: string;
}

function section(title: string, checkIds: readonly DoctorCheckId[]): DoctorSection {
  return Object.freeze({ checkIds: Object.freeze([...checkIds]), title });
}

const sections: readonly DoctorSection[] = Object.freeze([
  section("Platform", ["platform.runtime"]),
  section("Modules", [
    "modules.discovery",
    "modules.dependencies",
    "modules.permissions",
    "modules.lifecycle",
    "modules.configuration",
  ]),
  section("Data definitions", ["schemas.discovery", "migrations.discovery"]),
  section("PostgreSQL", ["database.transport", "postgresql.connection", "postgresql.plan"]),
  section("Identity", ["identity.configuration", "identity.client-address"]),
  section("Object storage", ["object-storage.integration", "object-storage.bindings"]),
  section("Outbound email", ["outbound-email.configuration"]),
]);

/**
 * Every check id, exactly once.
 *
 * A check absent from `sections` is still computed and still counted toward the overall result, but
 * is never shown — so a configuration failure would flip an operator's report to NOT READY with
 * nothing on screen explaining why. `outbound-email.configuration` was in precisely that state, and
 * `doctor-report.test.ts` now compares this list against the ids of a real report, so a new check
 * cannot be added without being rendered.
 */
export const RENDERED_DOCTOR_CHECK_IDS: readonly DoctorCheckId[] = Object.freeze(
  sections.flatMap((entry) => [...entry.checkIds]),
);

const statusSymbols: Readonly<Record<DoctorCheck["status"], string>> = Object.freeze({
  failure: "✗",
  pass: "✓",
  skipped: "○",
  warning: "!",
});

const resultLabels: Readonly<Record<DoctorResult, string>> = Object.freeze({
  "not-ready": "NOT READY",
  ready: "READY",
  "ready-with-warnings": "READY WITH WARNINGS",
});

export function formatDoctorReport(report: DoctorReport): readonly string[] {
  const checks = new Map(report.checks.map((check) => [check.id, check]));
  const lines = ["Ekklesia Doctor", ""];

  for (const [sectionIndex, section] of sections.entries()) {
    lines.push(section.title);
    for (const checkId of section.checkIds) {
      const check = checks.get(checkId);
      if (!check) {
        continue;
      }
      lines.push(`  ${statusSymbols[check.status]} ${check.summary}`);
      for (const detail of check.details) {
        lines.push(`    ${detail}`);
      }
    }
    if (sectionIndex < sections.length - 1) {
      lines.push("");
    }
  }

  lines.push("", `Result: ${resultLabels[report.result]}`);
  return Object.freeze(lines);
}