// ============================================================================
// Validators — Deterministic Math & Logic Checks (NO LLM!)
// Catches all the issues reported by the user programmatically.
// ============================================================================

import type {
  EstimationState,
  ValidationResult,
  ValidationError,
  ValidationWarning,
} from "./types.js";

/**
 * Run all deterministic validation checks on the final estimation state.
 */
export function validateEstimation(state: EstimationState): ValidationResult {
  const errors: ValidationError[] = [];
  const warnings: ValidationWarning[] = [];

  if (!state.formState) {
    return {
      passed: false,
      errors: [
        {
          code: "NO_FORM_STATE",
          message: "No form state available for validation.",
        },
      ],
      warnings: [],
    };
  }

  const fs = state.formState;

  // 1. PAGE COUNT PARITY
  validatePageCountParity(fs, errors);

  // 2. SORGLOS-BETRIEB IN SUMMARY
  validateSorglosBetrieb(fs, errors, warnings);

  // 3. NO VIDEOS AS PAGES
  validateNoVideosAsPages(fs, errors);

  // 4. EXTERNAL DOMAINS NOT AS PAGES
  validateExternalDomains(fs, state.concept?.siteProfile, errors);

  // 5. SERVICE COVERAGE
  validateServiceCoverage(fs, state.concept?.siteProfile, warnings);

  // 6. EXISTING FEATURE DETECTION
  validateExistingFeatures(fs, state.concept?.siteProfile, warnings);

  // 7. MULTILANG LABEL CORRECTNESS
  validateMultilangLabeling(fs, errors);

  // 8. INITIAL-PFLEGE UNITS
  validateInitialPflegeUnits(fs, warnings);

  // 9. SITEMAP vs PAGE LIST CONSISTENCY
  validateSitemapConsistency(fs, errors);

  return {
    passed: errors.length === 0,
    errors,
    warnings,
  };
}

/**
 * 1. Page count: the "Individuelle Seiten" position description must mention
 *    roughly the same number of pages as the sitemap contains.
 *    "er berechnet 15 Seiten nennt aber nur 11"
 *
 *    NOTE: fs.pages (from auditedFacts) is a conceptual list of page groups
 *    (e.g. "Leistungen") while the sitemap expands those into sub-pages.
 *    Therefore we do NOT compare fs.pages.length to the sitemap count.
 *    Instead, we verify that the position description text lists the right count.
 */
function validatePageCountParity(
  fs: Record<string, any>,
  errors: ValidationError[],
): void {
  // Count pages listed in the sitemap (the source of truth)
  let sitemapPageCount = 0;
  if (Array.isArray(fs.sitemap)) {
    for (const cat of fs.sitemap) {
      sitemapPageCount += (cat.pages || []).length;
    }
  }
  if (sitemapPageCount === 0) return;

  // Extract page names mentioned in the "Individuelle Seiten" position description
  const positions = fs.positionDescriptions || {};
  const pagesDesc =
    positions["Individuelle Seiten"] ||
    positions["2. Individuelle Seiten"] ||
    "";
  if (!pagesDesc) return;

  const descStr = typeof pagesDesc === "string" ? pagesDesc : "";

  // Count distinct page names mentioned (split by comma)
  // We avoid splitting by "&" or "und" because actual page names like
  // "Wartung & Störungsdienst" or "Genehmigungs- und Ausführungsplanung" contain them.
  const afterColon = descStr.includes(":")
    ? descStr.split(":").slice(1).join(":")
    : descStr;
  const segments = afterColon
    .split(/,/)
    .map((s: string) => s.replace(/\.$/, "").trim())
    .filter((s: string) => s.length > 2);

  // Handle consolidated references like "Leistungen (6 Unterseiten)" or "(inkl. Messen)"
  let mentionedCount = 0;
  for (const seg of segments) {
    const subPageMatch = seg.match(/\((\d+)\s+(?:Unter)?[Ss]eiten?\)/);
    if (subPageMatch) {
      mentionedCount += parseInt(subPageMatch[1], 10);
    } else if (seg.match(/\(inkl\.\s+/)) {
      // "Unternehmen (inkl. Messen)" = 2 pages
      mentionedCount += 2;
    } else {
      mentionedCount += 1;
    }
  }

  if (mentionedCount > 0 && Math.abs(mentionedCount - sitemapPageCount) > 2) {
    errors.push({
      code: "PAGE_COUNT_MISMATCH",
      message: `Seiten-Beschreibung nennt ~${mentionedCount} Seiten, aber ${sitemapPageCount} Seiten in der Sitemap.`,
      field: "positionDescriptions.Individuelle Seiten",
      expected: sitemapPageCount,
      actual: mentionedCount,
    });
  }
}

/**
 * 2. Sorglos-Betrieb must be included in summary.
 * "Zusammenfassung der Schätzung hat Sorglos-Betrieb nicht miteingenommen"
 */
function validateSorglosBetrieb(
  fs: Record<string, any>,
  errors: ValidationError[],
  _warnings: ValidationWarning[],
): void {
  const positions = fs.positionDescriptions || {};
  const hasPosition = Object.keys(positions).some(
    (k) =>
      k.toLowerCase().includes("sorglos") ||
      k.toLowerCase().includes("betrieb") ||
      k.toLowerCase().includes("pflege"),
  );

  if (!hasPosition) {
    errors.push({
      code: "MISSING_SORGLOS_BETRIEB",
      message: "Der Sorglos-Betrieb fehlt in den Position-Beschreibungen.",
      field: "positionDescriptions",
    });
  }
}

/**
 * 3. Videos must not be treated as separate pages.
 * "Er hat Videos als eigene Seite aufgenommen"
 */
function validateNoVideosAsPages(
  fs: Record<string, any>,
  errors: ValidationError[],
): void {
  const allPages = [...(fs.selectedPages || []), ...(fs.otherPages || [])];
  const sitemapPages = Array.isArray(fs.sitemap)
    ? fs.sitemap.flatMap((cat: any) =>
        (cat.pages || []).map((p: any) => p.title),
      )
    : [];

  const allPageNames = [...allPages, ...sitemapPages];
  const videoKeywords = ["video", "film", "messefilm", "imagefilm", "clip"];

  for (const pageName of allPageNames) {
    const lower = (typeof pageName === "string" ? pageName : "").toLowerCase();
    if (
      videoKeywords.some(
        (kw) => lower.includes(kw) && !lower.includes("leistung"),
      )
    ) {
      errors.push({
        code: "VIDEO_AS_PAGE",
        message: `"${pageName}" ist ein Video-Asset, keine eigene Seite.`,
        field: "sitemap",
      });
    }
  }
}

/**
 * 4. External sister-company domains must not be proposed as sub-pages.
 * "er hat ingenieursgesellschaft als seite integriert, die haben aber eine eigene website"
 */
function validateExternalDomains(
  fs: Record<string, any>,
  siteProfile: any,
  errors: ValidationError[],
): void {
  if (!siteProfile?.externalDomains?.length) return;

  const sitemapPages = Array.isArray(fs.sitemap)
    ? fs.sitemap.flatMap((cat: any) =>
        (cat.pages || []).map((p: any) => p.title || ""),
      )
    : [];

  for (const extDomain of siteProfile.externalDomains) {
    // Extract base name (e.g. "etib-ing" from "etib-ing.com")
    const baseName = extDomain
      .replace(/^www\./, "")
      .split(".")[0]
      .toLowerCase();

    for (const pageTitle of sitemapPages) {
      const lower = pageTitle.toLowerCase();
      // Check if the page title references the external company
      if (
        lower.includes(baseName) ||
        (lower.includes("ingenieur") && extDomain.includes("ing"))
      ) {
        errors.push({
          code: "EXTERNAL_DOMAIN_AS_PAGE",
          message: `"${pageTitle}" hat eine eigene Website (${extDomain}) und darf nicht als Unterseite vorgeschlagen werden.`,
          field: "sitemap",
        });
      }
    }
  }
}

/**
 * 5. Services from the existing site should be covered.
 * "er hat leistungen ausgelassen die ganz klar auf der kompetenz seite genannt werden"
 */
function validateServiceCoverage(
  fs: Record<string, any>,
  siteProfile: any,
  warnings: ValidationWarning[],
): void {
  if (!siteProfile?.services?.length) return;

  const allContent = JSON.stringify(fs).toLowerCase();

  for (const service of siteProfile.services) {
    const keywords = service
      .toLowerCase()
      .split(/[\s,&-]+/)
      .filter((w: string) => w.length > 4);

    const isCovered = keywords.some((kw: string) => allContent.includes(kw));

    if (!isCovered && service.length > 5) {
      warnings.push({
        code: "MISSING_SERVICE",
        message: `Bestehende Leistung "${service}" ist nicht in der Schätzung berücksichtigt.`,
        suggestion: `Prüfen ob "${service}" im Briefing gewünscht ist und ggf. in die Seitenstruktur aufnehmen.`,
      });
    }
  }
}

/**
 * 6. Existing features (search, forms) must be acknowledged.
 * "er hat die suchfunktion nicht bemerkt, die gibts schon auf der seite"
 */
function validateExistingFeatures(
  fs: Record<string, any>,
  siteProfile: any,
  warnings: ValidationWarning[],
): void {
  if (!siteProfile?.existingFeatures?.length) return;

  const functions = fs.functions || [];
  const features = fs.features || [];
  const allSelected = [...functions, ...features];

  for (const existingFeature of siteProfile.existingFeatures) {
    if (existingFeature === "cookie-consent") continue; // Standard, don't flag
    if (existingFeature === "video") continue; // Usually an asset, not a feature

    const isMapped = allSelected.some(
      (f: string) => f.toLowerCase() === existingFeature.toLowerCase(),
    );

    if (!isMapped) {
      warnings.push({
        code: "EXISTING_FEATURE_IGNORED",
        message: `Die bestehende Suchfunktion/Feature "${existingFeature}" wurde auf der aktuellen Website erkannt, aber nicht in der Schätzung berücksichtigt.`,
        suggestion: `"${existingFeature}" als Function oder Feature aufnehmen, da es bereits existiert und der Kunde es erwartet.`,
      });
    }
  }
}

/**
 * 7. Multilang +20% must not be labeled as API.
 * "die +20% beziehen sich nicht auf API"
 */
function validateMultilangLabeling(
  fs: Record<string, any>,
  errors: ValidationError[],
): void {
  const positions = fs.positionDescriptions || {};

  for (const [key, desc] of Object.entries(positions)) {
    if (
      key.toLowerCase().includes("api") ||
      key.toLowerCase().includes("schnittstelle")
    ) {
      const descStr = typeof desc === "string" ? desc : "";
      if (
        descStr.toLowerCase().includes("mehrsprach") ||
        descStr.toLowerCase().includes("multilang") ||
        descStr.toLowerCase().includes("20%")
      ) {
        errors.push({
          code: "MULTILANG_WRONG_POSITION",
          message: `Mehrsprachigkeit (+20%) ist unter "${key}" eingeordnet, gehört aber nicht zu API/Schnittstellen.`,
          field: key,
        });
      }
    }
  }
}

/**
 * 8. Initial-Pflege should refer to "Datensätze" not "Seiten".
 * "Initialpflege => 100€/Stk => damit sind keine Seiten sondern Datensätze"
 */
function validateInitialPflegeUnits(
  fs: Record<string, any>,
  warnings: ValidationWarning[],
): void {
  const positions = fs.positionDescriptions || {};

  for (const [key, desc] of Object.entries(positions)) {
    if (
      key.toLowerCase().includes("pflege") ||
      key.toLowerCase().includes("initial")
    ) {
      const descStr = typeof desc === "string" ? desc : "";
      if (
        descStr.toLowerCase().includes("seiten") &&
        !descStr.toLowerCase().includes("datensätz")
      ) {
        warnings.push({
          code: "INITIALPFLEGE_WRONG_UNIT",
          message: `"${key}" spricht von "Seiten", aber gemeint sind Datensätze (z.B. Produkte, Referenzen).`,
          suggestion: `Beschreibung auf "Datensätze" statt "Seiten" ändern.`,
        });
      }
    }
  }
}

/**
 * 9. Position descriptions must match calculated quantities.
 */
/**
 * 9. Position descriptions must match calculated quantities.
 */
// eslint-disable-next-line @typescript-eslint/no-unused-vars
function validatePositionDescriptionsMath(
  fs: Record<string, any>,
  errors: ValidationError[],
): void {
  const positions = fs.positionDescriptions || {};

  // Check pages description mentions correct count
  const pagesDesc =
    positions["Individuelle Seiten"] ||
    positions["2. Individuelle Seiten"] ||
    "";
  if (pagesDesc) {
    // Use the sitemap as the authoritative source of truth for page count
    let sitemapPageCount = 0;
    if (Array.isArray(fs.sitemap)) {
      for (const cat of fs.sitemap) {
        sitemapPageCount += (cat.pages || []).length;
      }
    }

    // Count how many page names are mentioned in the description
    const descStr = typeof pagesDesc === "string" ? pagesDesc : "";
    const mentionedPages = descStr
      .split(/,|und|&/)
      .filter((s: string) => s.trim().length > 2);

    if (
      sitemapPageCount > 0 &&
      mentionedPages.length > 0 &&
      Math.abs(mentionedPages.length - sitemapPageCount) > 2
    ) {
      errors.push({
        code: "PAGES_DESC_COUNT_MISMATCH",
        message: `Seiten-Beschreibung nennt ~${mentionedPages.length} Seiten, aber ${sitemapPageCount} in der Sitemap.`,
        field: "positionDescriptions.Individuelle Seiten",
        expected: sitemapPageCount,
        actual: mentionedPages.length,
      });
    }
  }
}

/**
 * 10. Sitemap categories should be consistent with selected pages/features.
 */
function validateSitemapConsistency(
  fs: Record<string, any>,
  errors: ValidationError[],
): void {
  if (!Array.isArray(fs.sitemap)) return;

  const sitemapTitles = fs.sitemap.flatMap((cat: any) =>
    (cat.pages || []).map((p: any) => (p.title || "").toLowerCase()),
  );

  // Check for "Verwaltung" page (hallucinated management page)
  for (const title of sitemapTitles) {
    if (title.includes("verwaltung") && !title.includes("inhalt")) {
      errors.push({
        code: "HALLUCINATED_MANAGEMENT_PAGE",
        message: `"Verwaltung" als Seite ist vermutlich halluziniert. Verwaltung ist typischerweise eine interne Funktion, keine öffentliche Webseite.`,
        field: "sitemap",
      });
    }
  }
}