import { BadRequestException, Injectable, NotFoundException, Inject } from "@nestjs/common";
import { Logger } from "nestjs-pino";
import { SalesforceConnection } from "../vendors/salesforce/services/salesforce-connection.service";
import { MappingsService } from "../mappings/mappings.service";
import { getErrorMessage } from "../common/utils/error.util";
import { WhmcsConnectionService } from "../vendors/whmcs/services/whmcs-connection.service";

interface CreateOrderBody {
  orderType: "Internet" | "eSIM" | "SIM" | "VPN" | "Other";
  selections: Record<string, unknown>;
  opportunityId?: string;
}

@Injectable()
export class OrdersService {
  constructor(
    @Inject(Logger) private readonly logger: Logger,
    private readonly sf: SalesforceConnection,
    private readonly mappings: MappingsService,
    private readonly whmcs: WhmcsConnectionService
  ) {}

  async create(userId: string, body: CreateOrderBody) {
    this.logger.log({ userId, orderType: body.orderType }, "Creating order request received");

    // 1) Validate mapping
    const mapping = await this.mappings.findByUserId(userId);
    if (!mapping?.sfAccountId || !mapping?.whmcsClientId) {
      this.logger.warn({ userId, mapping }, "Missing SF/WHMCS mapping for user");
      throw new BadRequestException("User is not fully linked to Salesforce/WHMCS");
    }

    // 2) Guards: ensure payment method exists and single Internet per account (if Internet)
    try {
      // Check client has at least one payment method (best-effort; will be enforced again at provision time)
      const pay = await this.whmcs.getPayMethods({ clientid: mapping.whmcsClientId });
      if (
        !pay?.paymethods ||
        !Array.isArray(pay.paymethods.paymethod) ||
        pay.paymethods.paymethod.length === 0
      ) {
        this.logger.warn({ userId }, "No WHMCS payment method on file");
        throw new BadRequestException("A payment method is required before ordering");
      }
    } catch (e) {
      this.logger.warn(
        { err: getErrorMessage(e) },
        "Payment method check soft-failed; proceeding cautiously"
      );
    }

    if (body.orderType === "Internet") {
      try {
        const products = await this.whmcs.getClientsProducts({ clientid: mapping.whmcsClientId });
        const existing = products?.products?.product || [];
        const hasInternet = existing.some((p: any) =>
          String(p.groupname || "")
            .toLowerCase()
            .includes("internet")
        );
        if (hasInternet) {
          throw new BadRequestException("An Internet service already exists for this account");
        }
      } catch (e) {
        this.logger.warn({ err: getErrorMessage(e) }, "Internet duplicate check soft-failed");
      }
    }

    // 3) Determine Portal pricebook
    const pricebook = await this.findPortalPricebookId();
    if (!pricebook) {
      throw new NotFoundException("Portal pricebook not found or inactive");
    }

    // 4) Build Order fields from selections (header)
    const today = new Date().toISOString().slice(0, 10); // YYYY-MM-DD
    const orderFields: any = {
      AccountId: mapping.sfAccountId,
      EffectiveDate: today,
      Status: "Pending Review",
      Pricebook2Id: pricebook,
      Order_Type__c: body.orderType,
      ...(body.opportunityId ? { OpportunityId: body.opportunityId } : {}),
    };

    // Activation
    if (body.selections.activationType)
      orderFields.Activation_Type__c = body.selections.activationType;
    if (body.selections.scheduledAt)
      orderFields.Activation_Scheduled_At__c = body.selections.scheduledAt;
    orderFields.Activation_Status__c = "Not Started";

    // Internet config
    if (body.orderType === "Internet") {
      if (body.selections.tier) orderFields.Internet_Plan_Tier__c = body.selections.tier;
      if (body.selections.mode) orderFields.Access_Mode__c = body.selections.mode;
      if (body.selections.speed) orderFields.Service_Speed__c = body.selections.speed;
      if (body.selections.install) orderFields.Installment_Plan__c = body.selections.install;
      if (typeof body.selections.weekend !== "undefined")
        orderFields.Weekend_Install__c =
          body.selections.weekend === "true" || body.selections.weekend === true;
      if (body.selections.install === "12-Month") orderFields.Installment_Months__c = 12;
      if (body.selections.install === "24-Month") orderFields.Installment_Months__c = 24;
    }

    // SIM/eSIM config
    if (body.orderType === "eSIM" || body.orderType === "SIM") {
      if (body.selections.simType)
        orderFields.SIM_Type__c = body.selections.simType === "eSIM" ? "eSIM" : "Physical SIM";
      if (body.selections.eid) orderFields.EID__c = body.selections.eid;
      if (body.selections.isMnp === "true" || body.selections.isMnp === true) {
        orderFields.MNP_Application__c = true;
        if (body.selections.mnpNumber)
          orderFields.MNP_Reservation_Number__c = body.selections.mnpNumber;
        if (body.selections.mnpExpiry) orderFields.MNP_Expiry_Date__c = body.selections.mnpExpiry;
        if (body.selections.mnpPhone) orderFields.MNP_Phone_Number__c = body.selections.mnpPhone;
      }
    }

    // 5) Create Order in Salesforce
    try {
      const created = await this.sf.sobject("Order").create(orderFields);
      if (!created?.id) {
        throw new Error("Salesforce did not return Order Id");
      }
      this.logger.log({ orderId: created.id }, "Salesforce Order created");

      // 6) Create OrderItems from header configuration
      await this.createOrderItems(created.id, body);

      return { sfOrderId: created.id, status: "Pending Review" };
    } catch (error) {
      this.logger.error(
        { err: getErrorMessage(error), orderFields },
        "Failed to create Salesforce Order"
      );
      throw error;
    }
  }

  async get(userId: string, sfOrderId: string) {
    try {
      const soql = `SELECT Id, Status, Activation_Status__c, Activation_Type__c, Activation_Scheduled_At__c, WHMCS_Order_ID__c FROM Order WHERE Id='${sfOrderId}'`;
      const res = await this.sf.query(soql);
      if (!res.records?.length) throw new NotFoundException("Order not found");
      const o = res.records[0];
      return {
        sfOrderId: o.Id,
        status: o.Status,
        activationStatus: o.Activation_Status__c,
        activationType: o.Activation_Type__c,
        scheduledAt: o.Activation_Scheduled_At__c,
        whmcsOrderId: o.WHMCS_Order_ID__c,
      };
    } catch (error) {
      this.logger.error(
        { err: getErrorMessage(error), sfOrderId },
        "Failed to fetch order summary"
      );
      throw error;
    }
  }

  async provision(userId: string, sfOrderId: string) {
    this.logger.log({ userId, sfOrderId }, "Provision request received");
    // 1) Fetch Order details from Salesforce
    const soql = `SELECT Id, Status, AccountId, Activation_Type__c, Activation_Scheduled_At__c, Order_Type__c, WHMCS_Order_ID__c FROM Order WHERE Id='${sfOrderId}'`;
    const res = await this.sf.query(soql);
    if (!res.records?.length) throw new NotFoundException("Order not found");
    const order = res.records[0];

    // 2) Validate allowed state
    if (
      order.Status !== "Activated" &&
      order.Status !== "Accepted" &&
      order.Status !== "Pending Review"
    ) {
      throw new BadRequestException("Order is not in a provisionable state");
    }

    // 3) Log and return a placeholder; actual WHMCS AddOrder/AcceptOrder will be wired by Flow trigger
    this.logger.log(
      { sfOrderId, orderType: order.Order_Type__c },
      "Provisioning not yet implemented; placeholder success"
    );
    return { sfOrderId, status: "Accepted", message: "Provisioning queued" };
  }
  private async findPortalPricebookId(): Promise<string | null> {
    try {
      const name = process.env.PORTAL_PRICEBOOK_NAME || "Portal";
      const soql = `SELECT Id, Name FROM Pricebook2 WHERE IsActive = true AND Name LIKE '%${name}%' LIMIT 1`;
      const result = await this.sf.query(soql);
      if (result.records?.length) return result.records[0].Id;
      // fallback to Standard Price Book
      const std = await this.sf.query(
        "SELECT Id FROM Pricebook2 WHERE IsStandard = true AND IsActive = true LIMIT 1"
      );
      return std.records?.[0]?.Id || null;
    } catch (error) {
      this.logger.error({ err: getErrorMessage(error) }, "Failed to find pricebook");
      return null;
    }
  }

  private async findPricebookEntryId(
    pricebookId: string,
    product2NameLike: string
  ): Promise<string | null> {
    const soql = `SELECT Id FROM PricebookEntry WHERE Pricebook2Id='${pricebookId}' AND IsActive=true AND Product2.Name LIKE '%${product2NameLike.replace("'", "")}%' LIMIT 1`;
    const res = await this.sf.query(soql);
    return res.records?.[0]?.Id || null;
  }

  private async findPricebookEntryBySku(pricebookId: string, sku: string): Promise<string | null> {
    if (!sku) return null;
    const skuField = process.env.PRODUCT_SKU_FIELD || "SKU__c";
    const safeSku = sku.replace(/'/g, "\\'");
    const soql = `SELECT Id FROM PricebookEntry WHERE Pricebook2Id='${pricebookId}' AND IsActive=true AND Product2.${skuField} = '${safeSku}' LIMIT 1`;
    const res = await this.sf.query(soql);
    return res.records?.[0]?.Id || null;
  }

  private async createOpportunity(
    accountId: string,
    body: CreateOrderBody
  ): Promise<string | null> {
    try {
      const now = new Date();
      const name = `${body.orderType} Service ${now.toISOString().slice(0, 10)}`;
      const opp = await this.sf.sobject("Opportunity").create({
        Name: name,
        AccountId: accountId,
        StageName: "Qualification",
        CloseDate: now.toISOString().slice(0, 10),
        Description: `Created from portal for ${body.orderType}`,
      });
      return opp?.id || null;
    } catch (e) {
      this.logger.error({ err: getErrorMessage(e) }, "Failed to create Opportunity");
      return null;
    }
  }

  private async createOrderItems(orderId: string, body: CreateOrderBody): Promise<void> {
    // Minimal SKU resolution using Product2.Name LIKE; in production, prefer Product2 external codes
    const pricebookId = await this.findPortalPricebookId();
    if (!pricebookId) return;

    const items: Array<{
      itemType: string;
      productHint?: string;
      sku?: string;
      billingCycle: string;
      quantity: number;
    }> = [];

    if (body.orderType === "Internet") {
      // Service line
      const svcHint = `Internet ${body.selections.tier || ""} ${body.selections.mode || ""}`.trim();
      items.push({
        itemType: "Service",
        productHint: svcHint,
        sku: body.selections.skuService as string | undefined,
        billingCycle: "monthly",
        quantity: 1,
      });
      // Installation line
      const install = body.selections.install as string;
      if (install === "One-time") {
        items.push({
          itemType: "Installation",
          productHint: "Installation Fee (Single)",
          sku: body.selections.skuInstall as string | undefined,
          billingCycle: "onetime",
          quantity: 1,
        });
      } else if (install === "12-Month") {
        items.push({
          itemType: "Installation",
          productHint: "Installation Fee (12-Month)",
          sku: body.selections.skuInstall as string | undefined,
          billingCycle: "monthly",
          quantity: 1,
        });
      } else if (install === "24-Month") {
        items.push({
          itemType: "Installation",
          productHint: "Installation Fee (24-Month)",
          sku: body.selections.skuInstall as string | undefined,
          billingCycle: "monthly",
          quantity: 1,
        });
      }
    } else if (body.orderType === "eSIM" || body.orderType === "SIM") {
      items.push({
        itemType: "Service",
        productHint: `${body.orderType} Plan`,
        sku: body.selections.skuService as string | undefined,
        billingCycle: "monthly",
        quantity: 1,
      });
    } else if (body.orderType === "VPN") {
      items.push({
        itemType: "Service",
        productHint: `VPN ${body.selections.region || ""}`,
        sku: body.selections.skuService as string | undefined,
        billingCycle: "monthly",
        quantity: 1,
      });
      items.push({
        itemType: "Installation",
        productHint: "VPN Activation Fee",
        sku: body.selections.skuInstall as string | undefined,
        billingCycle: "onetime",
        quantity: 1,
      });
    }

    for (const it of items) {
      if (!it.sku) {
        this.logger.warn({ itemType: it.itemType }, "Missing SKU for order item");
        throw new BadRequestException("Missing SKU for order item");
      }
      const pbe = await this.findPricebookEntryBySku(pricebookId, it.sku);
      if (!pbe) {
        this.logger.error({ sku: it.sku }, "PricebookEntry not found for SKU");
        throw new NotFoundException(`PricebookEntry not found for SKU ${it.sku}`);
      }
      await this.sf.sobject("OrderItem").create({
        OrderId: orderId,
        PricebookEntryId: pbe,
        Quantity: it.quantity,
        UnitPrice: null, // Salesforce will use the PBE price; null keeps pricebook price
        Billing_Cycle__c: it.billingCycle.toLowerCase() === "onetime" ? "Onetime" : "Monthly",
        Item_Type__c: it.itemType,
      });
    }
  }
}