import { NotificationChannel } from "../NotificationJobs/NotificationJobs.Interface";
import { CompanyNotificationPolicyAdapterMongoose } from "./CompanyNotificationPolicy.Adapter.Mongoose";
import { ClientNotificationPreferencesAdapterMongoose } from "./ClientNotificationPreferences.Adapter.Mongoose";
import { ClientCompanyNotificationOverrideAdapterMongoose } from "./ClientCompanyNotificationOverride.Adapter.Mongoose";
import { IClientNotificationPreferences } from "./ClientNotificationPreferences.Interface";
import { IClientCompanyNotificationOverride } from "./ClientCompanyNotificationOverride.Interface";
import { ICompanyNotificationPolicy } from "./CompanyNotificationPolicy.Interface";
import PlanSubscriptionsList from "../PlanSubscriptions/PlanSubscriptons";
import { PlanFeatures } from "../Plans/Plans.interface";
import ClientsList from "../Clients/Clients";

const DEFAULT_TIMEZONE = "America/Argentina/Buenos_Aires";
const SYSTEM_DEFAULT_CHANNELS: NotificationChannel[] = ["whatsapp", "email", "system"];

const PLAN_CHANNEL_MAP: Record<string, PlanFeatures> = {
    whatsapp: PlanFeatures.WAP_NOTIFICATIONS,
    email: PlanFeatures.MAIL_NOTIFICATIONS,
};

export interface ResolvedPolicy {
    channels: NotificationChannel[];
    timezone: string;
    quietHours?: { from: string; to: string };
    reminderRules?: { offset: number; enabled: boolean }[];
}

export class PolicyResolver {
    private companyPolicyAdapter: CompanyNotificationPolicyAdapterMongoose;
    private clientPreferencesAdapter: ClientNotificationPreferencesAdapterMongoose;
    private clientCompanyOverrideAdapter: ClientCompanyNotificationOverrideAdapterMongoose;

    constructor() {
        this.companyPolicyAdapter = new CompanyNotificationPolicyAdapterMongoose();
        this.clientPreferencesAdapter = new ClientNotificationPreferencesAdapterMongoose();
        this.clientCompanyOverrideAdapter = new ClientCompanyNotificationOverrideAdapterMongoose();
    }

    async resolve(companyId: string, clientId: string): Promise<ResolvedPolicy> {
        // Level 2: ClientCompanyNotificationOverride (per-client per-org)
        const override = await this.clientCompanyOverrideAdapter.findOne({
            clientId,
            companyId,
        });

        const client = await ClientsList.clients.findOne({ _id: clientId });

        // Level 3: ClientNotificationPreferences (user global)
        const clientPrefs = client?.userId
            ? await this.clientPreferencesAdapter.findOne({ userId: String(client.userId) })
            : null;

        // Level 4: CompanyNotificationPolicy (org defaults)
        const companyPolicy = await this.companyPolicyAdapter.findOne({ companyId });

        // Determine channels from cascade
        let channels: NotificationChannel[];
        let timezone: string;
        let quietHours: ResolvedPolicy["quietHours"];
        let reminderRules: ResolvedPolicy["reminderRules"];

        if (override) {
            channels = [...override.preferredChannels];
        } else if (clientPrefs) {
            channels = [...clientPrefs.preferredChannels];
        } else if (companyPolicy) {
            channels = [...companyPolicy.defaultChannels];
        } else {
            // Level 5: System defaults
            channels = [...SYSTEM_DEFAULT_CHANNELS];
        }

        // Apply muted channels from the winning level only — do NOT merge across levels
        const mutedChannels = this.getMutedChannels(override, clientPrefs, companyPolicy);
        channels = channels.filter((ch) => !mutedChannels.includes(ch));

        // Timezone and quiet hours from company policy
        if (companyPolicy) {
            timezone = companyPolicy.timezone;
            quietHours = companyPolicy.quietHours;
            reminderRules = companyPolicy.reminderRules;
        } else {
            timezone = DEFAULT_TIMEZONE;
        }

        // Level 1: Plan limits — filter channels by plan features
        channels = await this.applyPlanLimits(companyId, channels);

        return {
            channels,
            timezone,
            quietHours,
            reminderRules,
        };
    }

    async resolveAvailableChannels(
        companyId: string,
        channels: NotificationChannel[]
    ): Promise<NotificationChannel[]> {
        const companyPolicy = await this.companyPolicyAdapter.findOne({ companyId });
        const enabledChannels = companyPolicy
            ? companyPolicy.defaultChannels
            : SYSTEM_DEFAULT_CHANNELS;
        const companyEnabledChannels = channels.filter((channel) =>
            enabledChannels.includes(channel)
        );

        return this.applyPlanLimits(companyId, companyEnabledChannels);
    }

    /**
     * Returns muted channels from the winning cascade level only.
     * Per spec, muted channels are NOT merged across levels.
     * The level that determines preferredChannels also determines mutedChannels.
     */
    private getMutedChannels(
        override: IClientCompanyNotificationOverride | null,
        clientPrefs: IClientNotificationPreferences | null,
        companyPolicy: ICompanyNotificationPolicy | null
    ): NotificationChannel[] {
        if (override) {
            // Override wins — use only override's muted channels
            return override.mutedChannels || [];
        }
        if (clientPrefs) {
            // Client prefs wins — use only clientPrefs' muted channels
            return clientPrefs.mutedChannels || [];
        }
        if (companyPolicy) {
            // Company policy wins — use only companyPolicy' muted channels
            return companyPolicy.mutedChannels || [];
        }
        // System defaults — no muted channels
        return [];
    }

    private async applyPlanLimits(
        companyId: string,
        channels: NotificationChannel[]
    ): Promise<NotificationChannel[]> {
        // Resolve the company owner's userId for plan feature checks
        // Use lazy require to avoid circular dependency (PolicyResolver → CompaniesManager → Appointments → NotificationJobService → PolicyResolver)
        const CompaniesManager = require("../Companies/Companies").default;
        const company = await CompaniesManager.companies.findOne({ _id: companyId });
        if (!company) {
            // Company not found — return channels unchanged (fail-open)
            return channels;
        }

        const ownerUserId = String(company.ownerId);
        const filtered: NotificationChannel[] = [];

        for (const channel of channels) {
            const planFeature = PLAN_CHANNEL_MAP[channel];
            if (!planFeature) {
                // Channel has no plan restriction (e.g., system)
                filtered.push(channel);
                continue;
            }

            const canSend = await PlanSubscriptionsList.checkFeature({
                userId: ownerUserId,
                feature: planFeature,
            });

            if (canSend) {
                filtered.push(channel);
            }
        }

        return filtered;
    }
}