/**
 * ePay batch order queue.
 *
 * ePay has a GLOBAL cart per account — only one order can be processed
 * at a time. This queue ensures sequential execution.
 *
 * BATCH flow (correct — ONE order for N parcels):
 *   1. Check credits (need >= N)
 *   2. For each parcel: addToCart → saveMetadata
 *   3. ONE EditCartSubmit → ONE orderId
 *   4. Poll that orderId until "Finalizata"
 *   5. Download ALL documents from that order
 *   6. Store each in MinIO, update DB records
 */

import { prisma } from "@/core/storage/prisma";
import { EpayClient } from "./epay-client";
import { getEpayCredentials, updateEpayCredits } from "./epay-session-store";
import { storeCfExtract } from "./epay-storage";
import type { CfExtractCreateInput } from "./epay-types";

/* ------------------------------------------------------------------ */
/*  Types                                                              */
/* ------------------------------------------------------------------ */

type QueueItem = {
  extractId: string; // CfExtract.id in DB
  input: CfExtractCreateInput;
  basketRowId?: number; // set during cart phase
};

type BatchJob = {
  items: QueueItem[];
};

/* ------------------------------------------------------------------ */
/*  Global singleton queue                                             */
/* ------------------------------------------------------------------ */

const g = globalThis as {
  __epayBatchQueue?: BatchJob[];
  __epayQueueProcessing?: boolean;
  __epayDedupMap?: Map<string, { timestamp: number; extractIds: string[] }>;
};
if (!g.__epayBatchQueue) g.__epayBatchQueue = [];
if (!g.__epayDedupMap) g.__epayDedupMap = new Map();

/** TTL for dedup entries in milliseconds (60 seconds). */
const DEDUP_TTL_MS = 60_000;

/**
 * Build a dedup key from a list of cadastral numbers.
 * Sorted and joined so order doesn't matter.
 */
function batchDedupKey(inputs: CfExtractCreateInput[]): string {
  return inputs
    .map((i) => i.nrCadastral)
    .sort()
    .join(",");
}

/**
 * Remove expired entries from the dedup map.
 */
function cleanupDedupMap(): void {
  const now = Date.now();
  const map = g.__epayDedupMap!;
  for (const [key, entry] of map) {
    if (now - entry.timestamp > DEDUP_TTL_MS) {
      map.delete(key);
    }
  }
}

/* ------------------------------------------------------------------ */
/*  Public API                                                         */
/* ------------------------------------------------------------------ */

/**
 * Enqueue a single CF extract order (backwards compatible).
 * Creates a DB record, wraps as a batch of 1, and adds to the queue.
 */
export async function enqueueOrder(
  input: CfExtractCreateInput,
): Promise<string> {
  const ids = await enqueueBatch([input]);
  const first = ids[0];
  if (!first) throw new Error("enqueueBatch returned empty array");
  return first;
}

/**
 * Enqueue a batch of CF extract orders.
 * Creates all DB records, then processes as ONE ePay order.
 * Returns the CfExtract IDs immediately.
 *
 * Dedup protection: if the same set of cadastral numbers was enqueued
 * within the last 60 seconds, returns the existing extract IDs instead
 * of creating duplicate DB records and orders.
 */
export async function enqueueBatch(
  inputs: CfExtractCreateInput[],
): Promise<string[]> {
  if (inputs.length === 0) return [];

  // ── Dedup check ──
  cleanupDedupMap();
  const dedupKey = batchDedupKey(inputs);
  const existing = g.__epayDedupMap!.get(dedupKey);
  if (existing && Date.now() - existing.timestamp < DEDUP_TTL_MS) {
    console.log(
      `[epay-queue] Dedup hit: batch [${dedupKey}] was enqueued ${Math.round((Date.now() - existing.timestamp) / 1000)}s ago — returning existing IDs`,
    );
    return existing.extractIds;
  }

  const items: QueueItem[] = [];

  for (const input of inputs) {
    // Create DB record in "queued" status — use transaction + advisory lock
    // to prevent duplicate version numbers from concurrent requests
    const record = await prisma.$transaction(async (tx) => {
      await tx.$executeRaw`SELECT pg_advisory_xact_lock(hashtext(${'cfextract:' + input.nrCadastral}))`;
      const agg = await tx.cfExtract.aggregate({
        where: { nrCadastral: input.nrCadastral },
        _max: { version: true },
      });
      return tx.cfExtract.create({
        data: {
          nrCadastral: input.nrCadastral,
          nrCF: input.nrCF ?? input.nrCadastral,
          siruta: input.siruta,
          judetIndex: input.judetIndex,
          judetName: input.judetName,
          uatId: input.uatId,
          uatName: input.uatName,
          gisFeatureId: input.gisFeatureId,
          prodId: input.prodId ?? 14200,
          status: "queued",
          version: (agg._max.version ?? 0) + 1,
        },
      });
    });

    items.push({ extractId: record.id, input });
  }

  const extractIds = items.map((i) => i.extractId);

  // ── Record in dedup map ──
  g.__epayDedupMap!.set(dedupKey, {
    timestamp: Date.now(),
    extractIds,
  });

  g.__epayBatchQueue!.push({ items });

  console.log(
    `[epay-queue] Enqueued batch of ${items.length}: ${items.map((i) => i.input.nrCadastral).join(", ")} (queue=${g.__epayBatchQueue!.length})`,
  );

  // Start processing if not already running
  void processQueue();

  return extractIds;
}

/**
 * Get queue status for UI display.
 */
export function getQueueStatus(): {
  length: number;
  processing: boolean;
} {
  return {
    length: g.__epayBatchQueue?.length ?? 0,
    processing: g.__epayQueueProcessing ?? false,
  };
}

/* ------------------------------------------------------------------ */
/*  Queue Processor                                                    */
/* ------------------------------------------------------------------ */

async function processQueue(): Promise<void> {
  if (g.__epayQueueProcessing) return; // already running
  g.__epayQueueProcessing = true;

  // Track all orderIds from this session to avoid duplicates
  const knownOrderIds = new Set<string>();

  try {
    while (g.__epayBatchQueue && g.__epayBatchQueue.length > 0) {
      const batch = g.__epayBatchQueue.shift()!;
      const orderId = await processBatch(batch.items, knownOrderIds);
      if (orderId) knownOrderIds.add(orderId);
    }
  } finally {
    g.__epayQueueProcessing = false;
  }
}

async function updateStatus(
  id: string,
  status: string,
  extra?: Record<string, unknown>,
): Promise<void> {
  await prisma.cfExtract.update({
    where: { id },
    data: { status, ...extra },
  });
}

/**
 * Process a batch of items as ONE ePay order:
 *   1. Check credits (>= N)
 *   2. addToCart + saveMetadata for each
 *   3. ONE submitOrder
 *   4. Poll until complete
 *   5. Download + store ALL documents
 */
async function processBatch(
  items: QueueItem[],
  knownOrderIds: Set<string>,
): Promise<string | null> {
  const extractIds = items.map((i) => i.extractId);
  const count = items.length;

  try {
    // Get ePay credentials
    const creds = getEpayCredentials();
    if (!creds) {
      for (const id of extractIds) {
        await updateStatus(id, "failed", {
          errorMessage: "Nu ești conectat la ePay.",
        });
      }
      return null;
    }

    const client = await EpayClient.create(creds.username, creds.password);

    // Step 1: Check credits (need >= count)
    const credits = await client.getCredits();
    updateEpayCredits(credits);
    if (credits < count) {
      for (const id of extractIds) {
        await updateStatus(id, "failed", {
          errorMessage: `Credite insuficiente: ${credits} disponibile, ${count} necesare.`,
        });
      }
      return null;
    }

    // Step 2: addToCart + saveMetadata for EACH item
    for (const item of items) {
      const { extractId, input } = item;

      await updateStatus(extractId, "cart");
      const basketRowId = await client.addToCart(input.prodId ?? 14200);
      item.basketRowId = basketRowId;
      await updateStatus(extractId, "cart", { basketRowId });

      // Resolve county/UAT from SIRUTA if available
      let countyInternalId = input.judetIndex;
      let uatInternalId = input.uatId;
      let countyName = input.judetName;
      let uatName = input.uatName;

      if (input.siruta) {
        const uat = await prisma.gisUat.findUnique({
          where: { siruta: input.siruta },
          select: { workspacePk: true, county: true, name: true },
        });
        if (uat?.workspacePk) {
          countyInternalId = uat.workspacePk;
          uatInternalId = Number(input.siruta);
          if (uat.county) countyName = uat.county;
          if (uat.name) uatName = uat.name;
        }
      }

      const nrCF = input.nrCF ?? input.nrCadastral;
      await updateStatus(extractId, "ordering");

      const saved = await client.saveMetadata(
        basketRowId,
        countyInternalId,
        countyName,
        uatInternalId,
        uatName,
        nrCF,
        input.nrCadastral,
        process.env.ANCPI_DEFAULT_SOLICITANT_ID || "14452",
      );

      if (!saved) {
        await updateStatus(extractId, "failed", {
          errorMessage: "Salvarea metadatelor în ePay a eșuat.",
        });
        // Continue with remaining items — the cart still has them
        // but this one won't get metadata. Remove from batch.
        item.basketRowId = undefined;
      }
    }

    // Filter to only items that had successful metadata saves
    const validItems = items.filter((i) => i.basketRowId !== undefined);
    if (validItems.length === 0) {
      return null;
    }

    // Step 3: ONE submitOrder for ALL items
    console.log(
      `[epay-queue] Submitting order for ${validItems.length} items...`,
    );
    const orderId = await client.submitOrder(knownOrderIds);

    // Update all valid items with the shared orderId
    for (const item of validItems) {
      await updateStatus(item.extractId, "polling", { orderId });
    }

    // Step 4: Poll until complete
    const finalStatus = await client.pollUntilComplete(
      orderId,
      async (attempt, status) => {
        for (const item of validItems) {
          await updateStatus(item.extractId, "polling", {
            epayStatus: status,
            pollAttempts: attempt,
          });
        }
      },
    );

    if (
      finalStatus.status === "Anulata" ||
      finalStatus.status === "Plata refuzata"
    ) {
      for (const item of validItems) {
        await updateStatus(item.extractId, "cancelled", {
          epayStatus: finalStatus.status,
          errorMessage: `Comanda ${finalStatus.status.toLowerCase()}.`,
        });
      }
      return null;
    }

    // Step 5: Download ALL documents and match to items
    // The order may contain multiple documents — match by filename/nrCadastral
    const downloadableDocs = finalStatus.documents.filter(
      (d) => d.downloadValabil && d.contentType === "application/pdf",
    );

    console.log(
      `[epay-queue] Order ${orderId}: ${downloadableDocs.length} documents for ${validItems.length} items`,
    );

    // Match documents to items by CF number (from documentsByCadastral)
    // This is the CORRECT way — ePay returns docs in its own order, not ours

    if (downloadableDocs.length === 0) {
      for (const item of validItems) {
        await updateStatus(item.extractId, "failed", {
          epayStatus: finalStatus.status,
          errorMessage: "Nu s-au găsit documente PDF în comanda finalizată.",
        });
      }
      return orderId;
    }

    for (let i = 0; i < validItems.length; i++) {
      const item = validItems[i]!;
      const nrCF = item.input.nrCF ?? item.input.nrCadastral;

      // Try CF-based matching first (correct for batch orders)
      let doc = finalStatus.documentsByCadastral.get(nrCF);
      // Also try nrCadastral if different from nrCF
      if (!doc && item.input.nrCadastral !== nrCF) {
        doc = finalStatus.documentsByCadastral.get(item.input.nrCadastral);
      }
      // Last resort: fall back to index matching
      if (!doc) {
        doc = downloadableDocs[i];
        console.warn(
          `[epay-queue] Could not match by CF for ${item.input.nrCadastral}, using index ${i}`,
        );
      }

      if (!doc) {
        await updateStatus(item.extractId, "failed", {
          epayStatus: finalStatus.status,
          errorMessage: `Document lipsă (${downloadableDocs.length} documente pentru ${validItems.length} parcele).`,
        });
        continue;
      }

      try {
        await updateStatus(item.extractId, "downloading", {
          idDocument: doc.idDocument,
          documentName: doc.nume,
          documentDate: doc.dataDocument ? new Date(doc.dataDocument) : null,
        });

        const pdfBuffer = await client.downloadDocument(doc.idDocument, 4);

        // Step 6: Store in MinIO
        const { path, index } = await storeCfExtract(
          pdfBuffer,
          item.input.nrCadastral,
          {
            "ancpi-order-id": orderId,
            "nr-cadastral": item.input.nrCadastral,
            judet: item.input.judetName,
            uat: item.input.uatName,
            "data-document": doc.dataDocument ?? "",
            stare: finalStatus.status,
            produs: "EXI_ONLINE",
          },
        );

        // Complete — require document date from ANCPI for accurate expiry
        if (!doc.dataDocument) {
          console.warn(`[epay-queue] Missing dataDocument for extract ${item.extractId}, using download date`);
        }
        const documentDate = doc.dataDocument
          ? new Date(doc.dataDocument)
          : new Date();
        const expiresAt = new Date(documentDate);
        expiresAt.setDate(expiresAt.getDate() + 30);

        await updateStatus(item.extractId, "completed", {
          minioPath: path,
          minioIndex: index,
          epayStatus: finalStatus.status,
          completedAt: new Date(),
          documentDate,
          expiresAt,
        });

        console.log(
          `[epay-queue] Completed: ${item.input.nrCadastral} → ${path}`,
        );
      } catch (error) {
        const message =
          error instanceof Error ? error.message : "Eroare download/stocare";
        await updateStatus(item.extractId, "failed", {
          errorMessage: message,
        });
      }
    }

    // Update credits after successful order
    const newCredits = await client.getCredits();
    updateEpayCredits(newCredits);
    console.log(
      `[epay-queue] Batch complete: orderId=${orderId}, credits remaining=${newCredits}`,
    );

    return orderId;
  } catch (error) {
    const message =
      error instanceof Error ? error.message : "Eroare necunoscută";
    console.error(`[epay-queue] Batch failed:`, message);
    for (const id of extractIds) {
      await updateStatus(id, "failed", { errorMessage: message });
    }
    return null;
  }
}