/**
 * Contact Enricher v2 — Full Pipeline
 * 
 * Step 1: Find emails (Hunter.io + Pattern Generator + SMTP verify)
 *         Snov.io REMOVED — replaced by FREE email pattern generation
 * Step 2: Classify emails (Tier 1/2/3)
 * Step 3: Verify emails (7-layer deep)
 * Step 4: Find personal LinkedIn
 * Step 5: Find social profiles
 * Step 6: Filter for decision-makers only
 * 
 * Output: Verified, classified contacts ready for Phase 2
 */

import { searchHunterContacts, type HunterContact } from "../providers/hunter";
import { generateAndVerifyEmails, findEmailForPerson } from "./email-pattern-generator";
import { classifyEmail, type ClassificationResult } from "./email-classifier";
import { verifyEmailDeep, type VerificationResult } from "./email-verifier";
import { findPersonalLinkedIn, type PersonalLinkedIn } from "./linkedin-person-finder";
import { findSocialProfiles, type SocialProfiles } from "./social-finder";
import { getSupabaseClient } from "../../shared/supabase/client";
import { logger } from "../../shared/utils/logger";
import { randomUUID } from "crypto";

export interface EnrichedContact {
  id: string;
  companyId: string;
  fullName: string;
  title: string | null;
  seniority: string | null;

  // Email intelligence
  email: string | null;
  emailTier: string;                       // 'personal' | 'authority' | 'context_verified' | 'rejected'
  emailVerification: VerificationResult | null;
  emailClassification: ClassificationResult | null;

  // LinkedIn (both company and personal)
  linkedinPersonalUrl: string | null;
  linkedinPersonalConfidence: number;

  // Social
  socialProfiles: SocialProfiles | null;

  // Authority
  authorityConfirmed: boolean;
  authorityReason: string;

  // Source tracking
  source: "hunter" | "pattern" | "combined";
  providerConfidence: number;
}

/**
 * Full contact enrichment pipeline for a company.
 */
export async function enrichContacts(
  companyId: string,
  domain: string,
  companyName: string,
  employeeCount: number | null,
  industry: string,
  websiteSnippet: string,
  websiteHtml: string,
  companyLinkedInUrl: string | null,
  traceId: string
): Promise<EnrichedContact[]> {
  logger.info({ domain, companyName }, "Starting contact enrichment pipeline");

  // ── Step 1: Find emails from all providers ─────────────────
  const rawContacts = await findAllContacts(domain);
  
  if (rawContacts.length === 0) {
    logger.info({ domain }, "No contacts found from any provider");
    return [];
  }

  logger.info({ domain, found: rawContacts.length }, "Raw contacts from providers");

  // ── Step 2-6: Process each contact ─────────────────────────
  const enriched: EnrichedContact[] = [];

  for (const raw of rawContacts) {
    if (!raw.email) continue;

    // Step 2: Classify email (Tier 1/2/3)
    const classification = await classifyEmail(
      raw.email,
      { name: companyName, employeeCount, industry, websiteSnippet },
      traceId
    );

    // Rejected by classifier → skip entirely
    if (classification.verdict === "rejected") {
      logger.debug({ email: raw.email, reason: classification.reason }, "Email rejected by classifier");
      continue;
    }

    // Step 3: Deep verification (7 layers)
    const verification = await verifyEmailDeep(
      raw.email,
      domain,
      raw.confidence
    );

    // Hard invalid → skip
    if (verification.status === "rejected_invalid") {
      logger.debug({ email: raw.email }, "Email rejected by 7-layer verifier");
      continue;
    }

    // Step 4: Find personal LinkedIn
    let linkedin: PersonalLinkedIn | null = null;
    if (raw.fullName && raw.fullName.length > 3) {
      linkedin = await findPersonalLinkedIn(
        raw.fullName,
        companyName,
        domain,
        companyLinkedInUrl
      );
    }

    // Step 5: Social profiles (once per company, not per contact)
    // Social will be fetched separately at company level

    // Step 6: Authority check
    const { confirmed, reason } = checkAuthority(raw, classification);

    const contact: EnrichedContact = {
      id: randomUUID(),
      companyId,
      fullName: raw.fullName,
      title: raw.title,
      seniority: raw.seniority,
      email: raw.email,
      emailTier: classification.verdict,
      emailVerification: verification,
      emailClassification: classification,
      linkedinPersonalUrl: linkedin?.url ?? null,
      linkedinPersonalConfidence: linkedin?.confidence ?? 0,
      socialProfiles: null,  // set at company level
      authorityConfirmed: confirmed,
      authorityReason: reason,
      source: raw.source,
      providerConfidence: raw.confidence,
    };

    enriched.push(contact);
  }

  // Sort: authority-confirmed first, then by verification confidence
  enriched.sort((a, b) => {
    if (a.authorityConfirmed !== b.authorityConfirmed) return a.authorityConfirmed ? -1 : 1;
    return (b.emailVerification?.overallConfidence ?? 0) - (a.emailVerification?.overallConfidence ?? 0);
  });

  // Step 5: Social profiles for company (once)
  if (enriched.length > 0) {
    const social = await findSocialProfiles(domain, companyName, websiteHtml);
    for (const c of enriched) {
      c.socialProfiles = social;
    }
  }

  logger.info({
    domain,
    rawFound: rawContacts.length,
    afterClassification: enriched.length,
    authorityConfirmed: enriched.filter(c => c.authorityConfirmed).length,
    withLinkedIn: enriched.filter(c => c.linkedinPersonalUrl).length,
  }, "Contact enrichment pipeline complete");

  // Save to database
  await saveContacts(enriched);

  return enriched;
}

// ─── Find contacts from all providers ─────────────────────────
// Strategy: Hunter.io (free 25/mo) for names+titles+emails
//           Pattern Generator (FREE, unlimited) to find more emails
//           Snov.io REMOVED — replaced by pattern generation

interface RawContact {
  fullName: string;
  email: string;
  title: string | null;
  seniority: string | null;
  confidence: number;
  source: "hunter" | "pattern";
}

async function findAllContacts(domain: string): Promise<RawContact[]> {
  const contacts: RawContact[] = [];
  const seenEmails = new Set<string>();
  const namesFromHunter: { firstName: string; lastName: string; title: string | null; seniority: string | null }[] = [];

  // ── Source 1: Hunter.io (25 free/month) ─────────────────────
  // Hunter gives us NAMES + TITLES + EMAILS
  try {
    const hunterResults = await searchHunterContacts(domain);
    for (const h of hunterResults) {
      const email = h.value?.toLowerCase();
      const firstName = h.first_name ?? "";
      const lastName = h.last_name ?? "";
      const fullName = `${firstName} ${lastName}`.trim();

      // Save name for pattern generation later
      if (firstName && lastName) {
        namesFromHunter.push({
          firstName,
          lastName,
          title: h.position ?? null,
          seniority: h.seniority ?? null,
        });
      }

      if (email && !seenEmails.has(email)) {
        seenEmails.add(email);
        contacts.push({
          fullName,
          email,
          title: h.position ?? null,
          seniority: h.seniority ?? null,
          confidence: h.confidence ?? 0,
          source: "hunter",
        });
      }
    }
  } catch (err) {
    logger.warn({ domain, err }, "Hunter search failed — falling back to pattern generation");
  }

  // ── Source 2: Pattern Generator (FREE, UNLIMITED) ──────────
  // For names we got from Hunter that DON'T have emails,
  // OR if Hunter returned no results at all
  for (const person of namesFromHunter) {
    // Check if we already have an email for this person
    const hasEmail = contacts.some(c =>
      c.fullName.toLowerCase().includes(person.firstName.toLowerCase()) &&
      c.fullName.toLowerCase().includes(person.lastName.toLowerCase())
    );

    if (!hasEmail) {
      // Generate email patterns and SMTP verify (FREE)
      const generated = await findEmailForPerson(
        `${person.firstName} ${person.lastName}`,
        domain
      );

      if (generated && generated.smtpStatus === "deliverable" && !seenEmails.has(generated.email)) {
        seenEmails.add(generated.email);
        contacts.push({
          fullName: `${person.firstName} ${person.lastName}`,
          email: generated.email,
          title: person.title,
          seniority: person.seniority,
          confidence: generated.confidence * 100,
          source: "pattern",
        });
      }
    }
  }

  // ── Source 3: If still no contacts, try common owner patterns ─
  if (contacts.length === 0) {
    // Try generic owner/manager patterns
    const ownerPatterns = ["info", "contact", "hello", "admin"];
    for (const prefix of ownerPatterns) {
      const email = `${prefix}@${domain}`;
      if (!seenEmails.has(email)) {
        seenEmails.add(email);
        contacts.push({
          fullName: "Unknown",
          email,
          title: null,
          seniority: null,
          confidence: 20,
          source: "pattern",
        });
      }
    }
  }

  logger.info({
    domain,
    hunterContacts: contacts.filter(c => c.source === "hunter").length,
    patternContacts: contacts.filter(c => c.source === "pattern").length,
    total: contacts.length,
  }, "Contact finding complete (Hunter + Pattern Generator)");

  return contacts;
}

// ─── Authority check ─────────────────────────────────────────

function checkAuthority(
  contact: RawContact,
  classification: ClassificationResult
): { confirmed: boolean; reason: string } {
  // Personal email with senior title → confirmed
  const seniorTitles = /\b(ceo|cto|coo|cfo|cmo|founder|co-founder|owner|partner|director|vp|vice\s*president|president|head|principal|managing|general\s*manager)\b/i;

  if (classification.verdict === "personal" && contact.title && seniorTitles.test(contact.title)) {
    return { confirmed: true, reason: `Personal email + senior title: ${contact.title}` };
  }

  if (classification.verdict === "authority") {
    return { confirmed: true, reason: `Authority email prefix: ${contact.email.split("@")[0]}` };
  }

  if (classification.verdict === "personal") {
    return { confirmed: true, reason: "Personal email format — likely individual decision maker" };
  }

  if (classification.verdict === "context_verified" && classification.confidence >= 0.7) {
    return { confirmed: true, reason: classification.reason };
  }

  if (classification.verdict === "outsourcing") {
    return { confirmed: false, reason: "Outsourcing/vendor email — may reach procurement, not decision maker" };
  }

  return { confirmed: false, reason: "Authority not confirmed" };
}

// ─── Save to database ────────────────────────────────────────

async function saveContacts(contacts: EnrichedContact[]): Promise<void> {
  const db = getSupabaseClient();

  for (const c of contacts) {
    try {
      await db.from("contacts").upsert({
        id: c.id,
        company_id: c.companyId,
        full_name: c.fullName,
        title: c.title,
        seniority: c.seniority,
        email: c.email,
        email_verified: c.emailVerification?.status === "verified_deliverable",
        email_tier: c.emailTier,
        email_verification_layers: c.emailVerification?.layers ?? {},
        linkedin_personal_url: c.linkedinPersonalUrl,
        social_profiles: c.socialProfiles ?? {},
        authority_confirmed: c.authorityConfirmed,
        confidence: c.emailVerification?.overallConfidence ?? c.providerConfidence,
        source: c.source,
      }, { onConflict: "company_id,email" });
    } catch (err) {
      logger.warn({ email: c.email, err }, "Contact save failed — continuing");
    }
  }
}