import AsyncStorage from "@react-native-async-storage/async-storage";
import { create } from "zustand";
import { createJSONStorage, persist } from "zustand/middleware";

export type ProfileMode = "personal" | "corporate";

export type OrgMembership = {
  orgId: string;
  orgName: string;
  planName: string;
  remainingAllowance: number;
  monthlyCap: number;
};

type ProfileState = {
  mode: ProfileMode;
  memberships: OrgMembership[];
  activeOrgId: string | null;
  setMode: (mode: ProfileMode) => void;
  setActiveOrg: (orgId: string | null) => void;
  joinOrg: (code: string) => { ok: boolean; message: string };
  activeMembership: () => OrgMembership | null;
  quoteSplit: (subtotal: number) => { covered: number; selfPay: number };
  consumeAllowance: (amount: number) => void;
};

const DEMO_ORGS: Record<string, OrgMembership> = {
  "GISHEN-BANK": {
    orgId: "org_bank",
    orgName: "Demo Bank Ethiopia",
    planName: "Staff",
    remainingAllowance: 2500,
    monthlyCap: 5000,
  },
  "GISHEN-NGO": {
    orgId: "org_ngo",
    orgName: "Demo NGO",
    planName: "Standard",
    remainingAllowance: 1200,
    monthlyCap: 3000,
  },
};

const seededMembership = { ...DEMO_ORGS["GISHEN-BANK"] };

export const useProfileModeStore = create<ProfileState>()(
  persist(
    (set, get) => ({
      mode: "personal",
      memberships: [seededMembership],
      activeOrgId: null,
      setMode: (mode) => set({ mode }),
      setActiveOrg: (orgId) =>
        set({ activeOrgId: orgId, mode: orgId ? "corporate" : "personal" }),
      joinOrg: (code) => {
        const key = code.trim().toUpperCase();
        const org = DEMO_ORGS[key];
        if (!org) return { ok: false, message: "Invalid join code" };
        const memberships = get().memberships;
        if (memberships.some((m) => m.orgId === org.orgId)) {
          set({ activeOrgId: org.orgId, mode: "corporate" });
          return { ok: true, message: "Already a member — switched to org" };
        }
        set({
          memberships: [...memberships, { ...org }],
          activeOrgId: org.orgId,
          mode: "corporate",
        });
        return { ok: true, message: `Joined ${org.orgName}` };
      },
      activeMembership: () => {
        const { activeOrgId, memberships, mode } = get();
        if (mode !== "corporate" || !activeOrgId) return null;
        return memberships.find((m) => m.orgId === activeOrgId) ?? null;
      },
      quoteSplit: (subtotal) => {
        const m = get().activeMembership();
        if (!m) return { covered: 0, selfPay: subtotal };
        const covered = Math.min(subtotal, m.remainingAllowance);
        return { covered, selfPay: Math.max(0, subtotal - covered) };
      },
      consumeAllowance: (amount) => {
        const { activeOrgId, memberships } = get();
        if (!activeOrgId || amount <= 0) return;
        set({
          memberships: memberships.map((m) =>
            m.orgId === activeOrgId
              ? {
                  ...m,
                  remainingAllowance: Math.max(0, m.remainingAllowance - amount),
                }
              : m
          ),
        });
      },
    }),
    {
      name: "gishen-profile-mode",
      storage: createJSONStorage(() => AsyncStorage),
      version: 2,
      migrate: (persisted: unknown) => {
        const state = (persisted ?? {}) as Partial<ProfileState>;
        return !state.memberships?.length
          ? { ...state, memberships: [seededMembership] }
          : state;
      },
    }
  )
);