import { apiClient } from './httpClient';
import { Role, Claim } from '../types';
import { ROLE_CLAIM_DEFINITIONS } from '../auth/rbac';

export const LOCAL_STORAGE_SYSTEM_ROLES_KEY = 'pfm_cache_system_roles';
export const LOCAL_STORAGE_ROLE_CLAIMS_PREFIX = 'pfm_cache_role_claims_';
export const LOCAL_STORAGE_SYSTEM_CLAIMS_KEY = 'pfm_cache_system_claims';
export const LOCAL_STORAGE_RBAC_VERSION_KEY = 'pfm_rbac_cache_version';
export const CURRENT_RBAC_CACHE_VERSION = 'v2.2';

/**
 * Invalidates and purges legacy cached claims if the schema version differs.
 */
export function ensureFreshRbacCache(): void {
  if (typeof window === 'undefined') return;
  try {
    const version = localStorage.getItem(LOCAL_STORAGE_RBAC_VERSION_KEY);
    if (version !== CURRENT_RBAC_CACHE_VERSION) {
      // Clear legacy claims and caches
      const keysToRemove: string[] = [];
      for (let i = 0; i < localStorage.length; i++) {
        const key = localStorage.key(i);
        if (key && (key.startsWith(LOCAL_STORAGE_ROLE_CLAIMS_PREFIX) || key === 'pfm_user_claims')) {
          keysToRemove.push(key);
        }
      }
      keysToRemove.forEach((k) => localStorage.removeItem(k));
      inMemoryRoleClaims.clear();
      localStorage.setItem(LOCAL_STORAGE_RBAC_VERSION_KEY, CURRENT_RBAC_CACHE_VERSION);
    }
  } catch {}
}

// In-memory runtime caches
let inMemorySystemRoles: Role[] | null = null;
const inMemoryRoleClaims = new Map<string, Claim[]>();
let inMemorySystemClaims: Claim[] | null = null;
const inMemoryUserRoles = new Map<string, { roles: Role[]; timestamp: number }>();
const inMemoryUserClaims = new Map<string, { claims: Claim[]; timestamp: number }>();
const USER_RBAC_CACHE_TTL_MS = 5 * 60 * 1000; // 5 minutes

// Initial check on load
ensureFreshRbacCache();

// Standard role claim defaults matching PFM Identity Server specification
export const DEFAULT_ROLE_CLAIMS: Record<string, Claim[]> = {
  contributor: [
    { claimId: 30, claimType: 'projects_milestones', claimValue: 'view, add' },
    { claimId: 31, claimType: 'grant_financials', claimValue: 'view, add' },
    { claimId: 32, claimType: 'evidence_risks', claimValue: 'view, add' },
    { claimId: 33, claimType: 'beneficiaries', claimValue: 'view, add' },
    { claimId: 34, claimType: 'change_management', claimValue: 'view, add' },
    { claimId: 35, claimType: 'site_visits', claimValue: 'view, add' },
    { claimId: 36, claimType: 'settings_invites', claimValue: 'view, add' },
  ],
  supervisor: [
    { claimId: 20, claimType: 'dashboard', claimValue: 'view, export' },
    { claimId: 38, claimType: 'compliance', claimValue: 'view, export' },
    { claimId: 21, claimType: 'projects_milestones', claimValue: 'view, add, update, export' },
    { claimId: 22, claimType: 'grant_financials', claimValue: 'view, add, update, export' },
    { claimId: 23, claimType: 'evidence_risks', claimValue: 'view, add, update, export' },
    { claimId: 24, claimType: 'beneficiaries', claimValue: 'view, add, update, export' },
    { claimId: 25, claimType: 'change_management', claimValue: 'view, add, update, export' },
    { claimId: 26, claimType: 'site_visits', claimValue: 'view, add, update, export' },
    { claimId: 27, claimType: 'settings_invites', claimValue: 'view, add, update, export' },
    { claimId: 28, claimType: 'settings_users', claimValue: 'view, add, update, export' },
  ],
  manager: [
    { claimId: 10, claimType: 'dashboard', claimValue: 'all' },
    { claimId: 39, claimType: 'compliance', claimValue: 'all' },
    { claimId: 11, claimType: 'projects_milestones', claimValue: 'all' },
    { claimId: 12, claimType: 'grant_financials', claimValue: 'all' },
    { claimId: 13, claimType: 'evidence_risks', claimValue: 'all' },
    { claimId: 14, claimType: 'beneficiaries', claimValue: 'all' },
    { claimId: 15, claimType: 'change_management', claimValue: 'all' },
    { claimId: 16, claimType: 'site_visits', claimValue: 'all' },
    { claimId: 17, claimType: 'settings_invites', claimValue: 'all' },
    { claimId: 18, claimType: 'settings_users', claimValue: 'all' },
    { claimId: 19, claimType: 'settings_auditlog', claimValue: 'all' },
    { claimId: 29, claimType: 'settings_notifications', claimValue: 'all' },
    { claimId: 37, claimType: 'tenant_self_service', claimValue: 'all' },
  ],
  executive: [
    { claimId: 1, claimType: 'dashboard', claimValue: 'all' },
    { claimId: 40, claimType: 'compliance', claimValue: 'all' },
    { claimId: 2, claimType: 'governance', claimValue: 'all' },
    { claimId: 3, claimType: 'projects_milestones', claimValue: 'all' },
    { claimId: 4, claimType: 'grant_financials', claimValue: 'all' },
    { claimId: 5, claimType: 'evidence_risks', claimValue: 'all' },
    { claimId: 6, claimType: 'tenant_self_service', claimValue: 'all' },
  ],
  admin: [
    { claimId: 99, claimType: 'unrestricted', claimValue: 'all' },
  ],
};

/**
 * Normalizes claim objects to contain both claimType/claimValue and type/value
 */
export function normalizeClaim(c: any): Claim {
  const claimType = c.claimType || c.type || c.name || '';
  const claimValue = c.claimValue || c.value || 'all';
  const claimId = c.claimId ?? c.id ?? undefined;
  return {
    ...c,
    type: claimType,
    value: claimValue,
    claimType,
    claimValue,
    claimId,
  };
}

/**
 * Retrieve cached system roles from memory or localStorage.
 */
export function getCachedSystemRoles(): Role[] | null {
  if (inMemorySystemRoles && inMemorySystemRoles.length > 0) {
    return inMemorySystemRoles;
  }
  if (typeof window !== 'undefined') {
    try {
      const raw = localStorage.getItem(LOCAL_STORAGE_SYSTEM_ROLES_KEY);
      if (raw) {
        const parsed = JSON.parse(raw);
        if (Array.isArray(parsed) && parsed.length > 0) {
          inMemorySystemRoles = parsed;
          return parsed;
        }
      }
    } catch {}
  }
  return null;
}

/**
 * Store system roles into memory and localStorage.
 */
export function setCachedSystemRoles(roles: Role[]): void {
  inMemorySystemRoles = roles;
  if (typeof window !== 'undefined') {
    try {
      localStorage.setItem(LOCAL_STORAGE_SYSTEM_ROLES_KEY, JSON.stringify(roles));
    } catch {}
  }
}

/**
 * Retrieve cached role claims for a specific role ID or role name.
 */
export function getCachedRoleClaims(roleKey: string): Claim[] | null {
  const normalizedKey = roleKey.toLowerCase().trim();
  if (inMemoryRoleClaims.has(normalizedKey)) {
    return inMemoryRoleClaims.get(normalizedKey)!;
  }
  if (typeof window !== 'undefined') {
    try {
      const raw = localStorage.getItem(`${LOCAL_STORAGE_ROLE_CLAIMS_PREFIX}${normalizedKey}`);
      if (raw) {
        const parsed = JSON.parse(raw);
        if (Array.isArray(parsed)) {
          const normalized = parsed.map(normalizeClaim);
          inMemoryRoleClaims.set(normalizedKey, normalized);
          return normalized;
        }
      }
    } catch {}
  }
  return null;
}

/**
 * Store role claims into memory and localStorage.
 */
export function setCachedRoleClaims(roleKey: string, claims: Claim[]): void {
  const normalizedKey = roleKey.toLowerCase().trim();
  const normalized = claims.map(normalizeClaim);
  inMemoryRoleClaims.set(normalizedKey, normalized);
  if (typeof window !== 'undefined') {
    try {
      localStorage.setItem(
        `${LOCAL_STORAGE_ROLE_CLAIMS_PREFIX}${normalizedKey}`,
        JSON.stringify(normalized)
      );
    } catch {}
  }
}

/**
 * Fetches system roles from backend API, caching the result in memory and localStorage.
 * Checks cache first to avoid redundant network round trips.
 */
export async function fetchAndCacheSystemRoles(forceRefresh = false): Promise<Role[]> {
  if (!forceRefresh) {
    const cached = getCachedSystemRoles();
    if (cached && cached.length > 0) return cached;
  }

  try {
    const res = await apiClient.get<Role[]>('/v1/api/users/system/roles');
    if (res.data && Array.isArray(res.data) && res.data.length > 0) {
      setCachedSystemRoles(res.data);
      return res.data;
    }
  } catch (err) {
    // If request fails, fall back to cached roles
  }

  const cached = getCachedSystemRoles();
  if (cached && cached.length > 0) return cached;

  // Fallback defaults if offline / bootstrapping
  const defaults: Role[] = [
    { id: '1', name: 'Admin' },
    { id: '2', name: 'Executive' },
    { id: '3', name: 'Supervisor' },
    { id: '4', name: 'Manager' },
    { id: '5', name: 'Contributor' },
  ];
  setCachedSystemRoles(defaults);
  return defaults;
}

const GUID_REGEX = /^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$/;

/**
 * Fetches role claims for a role from the API, caching them under role ID and role name.
 * Uses cache-first strategy to eliminate sequential network waterfalls on startup.
 */
export async function fetchAndCacheRoleClaims(
  roleId: string,
  roleName?: string,
  forceRefresh = false
): Promise<Claim[]> {
  const roleIdKey = roleId.toLowerCase().trim();
  const roleNameKey = (roleName || '').toLowerCase().trim();

  // 1. Check in-memory and localStorage cache first
  if (!forceRefresh) {
    const cachedById = getCachedRoleClaims(roleIdKey);
    if (cachedById && cachedById.length > 0) return cachedById;

    if (roleNameKey) {
      const cachedByName = getCachedRoleClaims(roleNameKey);
      if (cachedByName && cachedByName.length > 0) return cachedByName;
    }
  }

  // 2. Resolve actual GUID if roleId is not formatted as a GUID
  let effectiveGuid = GUID_REGEX.test(roleId.trim()) ? roleId.trim() : null;
  if (!effectiveGuid) {
    const cachedRoles = getCachedSystemRoles();
    if (cachedRoles && cachedRoles.length > 0) {
      const match = cachedRoles.find(
        (r) =>
          (r.name && r.name.toLowerCase() === roleNameKey) ||
          (r.name && r.name.toLowerCase() === roleIdKey) ||
          String(r.id).toLowerCase() === roleIdKey
      );
      if (match && match.id && GUID_REGEX.test(String(match.id).trim())) {
        effectiveGuid = String(match.id).trim();
      }
    }
  }

  if (effectiveGuid) {
    try {
      const res = await apiClient.get<Claim[]>(`/v1/api/users/system/roles/${effectiveGuid}/claims`);
      if (res.data && Array.isArray(res.data) && res.data.length > 0) {
        const normalized = res.data.map(normalizeClaim);
        setCachedRoleClaims(roleIdKey, normalized);
        if (roleNameKey) setCachedRoleClaims(roleNameKey, normalized);
        if (effectiveGuid.toLowerCase() !== roleIdKey) {
          setCachedRoleClaims(effectiveGuid.toLowerCase(), normalized);
        }
        return normalized;
      }
    } catch (err) {
      // Network or server error, proceed to cache / defaults fallback
    }
  }

  // Re-check cache by role ID or name
  const cachedById = getCachedRoleClaims(roleIdKey);
  if (cachedById && cachedById.length > 0) return cachedById;

  if (roleNameKey) {
    const cachedByName = getCachedRoleClaims(roleNameKey);
    if (cachedByName && cachedByName.length > 0) return cachedByName;
  }

  // Fallback from predefined matrix
  const fallback = (roleNameKey && DEFAULT_ROLE_CLAIMS[roleNameKey]) || DEFAULT_ROLE_CLAIMS[roleIdKey] || [];
  const normalized = fallback.map(normalizeClaim);
  setCachedRoleClaims(roleIdKey, normalized);
  if (roleNameKey) setCachedRoleClaims(roleNameKey, normalized);
  return normalized;
}

export function clearCachedUserRbac(userId?: string): void {
  if (userId) {
    const key = userId.toLowerCase().trim();
    inMemoryUserRoles.delete(key);
    inMemoryUserClaims.delete(key);
    if (typeof window !== 'undefined') {
      try {
        localStorage.removeItem(`pfm_cache_user_roles_${key}`);
        localStorage.removeItem(`pfm_cache_user_claims_${key}`);
      } catch {}
    }
  } else {
    inMemoryUserRoles.clear();
    inMemoryUserClaims.clear();
    if (typeof window !== 'undefined') {
      try {
        const keysToRemove: string[] = [];
        for (let i = 0; i < localStorage.length; i++) {
          const k = localStorage.key(i);
          if (k && (k.startsWith('pfm_cache_user_roles_') || k.startsWith('pfm_cache_user_claims_'))) {
            keysToRemove.push(k);
          }
        }
        keysToRemove.forEach((k) => localStorage.removeItem(k));
      } catch {}
    }
  }
}

/**
 * Direct API calls for user roles and user claims with session-level caching
 */
export async function getUserRolesFromApi(userId: string, forceRefresh = false): Promise<Role[]> {
  const key = userId.toLowerCase().trim();
  if (!forceRefresh) {
    const cached = inMemoryUserRoles.get(key);
    if (cached && Date.now() - cached.timestamp < USER_RBAC_CACHE_TTL_MS) {
      return cached.roles;
    }
    if (typeof window !== 'undefined') {
      try {
        const raw = localStorage.getItem(`pfm_cache_user_roles_${key}`);
        if (raw) {
          const parsed = JSON.parse(raw);
          if (Array.isArray(parsed) && parsed.length > 0) {
            inMemoryUserRoles.set(key, { roles: parsed, timestamp: Date.now() });
            return parsed;
          }
        }
      } catch {}
    }
  }

  try {
    const res = await apiClient.get<Role[]>(`/v1/api/users/${userId}/roles`);
    const roles = res.data || [];
    if (roles.length > 0) {
      inMemoryUserRoles.set(key, { roles, timestamp: Date.now() });
      if (typeof window !== 'undefined') {
        try {
          localStorage.setItem(`pfm_cache_user_roles_${key}`, JSON.stringify(roles));
        } catch {}
      }
    }
    return roles;
  } catch {
    return inMemoryUserRoles.get(key)?.roles || [];
  }
}

export async function getUserClaimsFromApi(userId: string, forceRefresh = false): Promise<Claim[]> {
  const key = userId.toLowerCase().trim();
  if (!forceRefresh) {
    const cached = inMemoryUserClaims.get(key);
    if (cached && Date.now() - cached.timestamp < USER_RBAC_CACHE_TTL_MS) {
      return cached.claims;
    }
    if (typeof window !== 'undefined') {
      try {
        const raw = localStorage.getItem(`pfm_cache_user_claims_${key}`);
        if (raw) {
          const parsed = JSON.parse(raw);
          if (Array.isArray(parsed) && parsed.length > 0) {
            const normalized = parsed.map(normalizeClaim);
            inMemoryUserClaims.set(key, { claims: normalized, timestamp: Date.now() });
            return normalized;
          }
        }
      } catch {}
    }
  }

  try {
    const res = await apiClient.get<Claim[]>(`/v1/api/users/${userId}/claims`);
    const claims = (res.data || []).map(normalizeClaim);
    if (claims.length > 0) {
      inMemoryUserClaims.set(key, { claims, timestamp: Date.now() });
      if (typeof window !== 'undefined') {
        try {
          localStorage.setItem(`pfm_cache_user_claims_${key}`, JSON.stringify(claims));
        } catch {}
      }
    }
    return claims;
  } catch {
    return inMemoryUserClaims.get(key)?.claims || [];
  }
}

/**
 * Resolves user roles, role claims, and user claims (including tenant and tenant_id)
 * concurrently using Promise.allSettled and caches system roles and claims.
 */
export async function resolveUserRolesAndClaims(
  userSub: string,
  initialClaims: Record<string, any> = {},
  currentProfile: { role?: string; tenant?: string; tenant_id?: number } = {}
): Promise<{
  roles: string[];
  claims: Record<string, any>;
  primaryRole: string;
  tenant?: string;
  tenant_id?: number;
}> {
  ensureFreshRbacCache();
  const mergedClaims: Record<string, any> = { ...initialClaims };
  const resolvedRoles: string[] = [];
  let userRoleObjects: Role[] = [];
  let primaryRole = currentProfile.role || (initialClaims.role as string) || '';
  let tenant = currentProfile.tenant || (initialClaims.tenant as string) || undefined;
  let tenant_id = currentProfile.tenant_id ?? (initialClaims.tenant_id ? Number(initialClaims.tenant_id) : undefined);

  // 1. Concurrently fetch user's roles and user's claims in parallel
  const [rolesResult, claimsResult] = await Promise.allSettled([
    userSub ? getUserRolesFromApi(userSub) : Promise.resolve([]),
    userSub ? getUserClaimsFromApi(userSub) : Promise.resolve([]),
  ]);

  if (rolesResult.status === 'fulfilled' && Array.isArray(rolesResult.value) && rolesResult.value.length > 0) {
    userRoleObjects = rolesResult.value;
    rolesResult.value.forEach((r) => {
      if (r.name && !resolvedRoles.includes(r.name)) {
        resolvedRoles.push(r.name);
      }
    });
    if (resolvedRoles.length > 0) {
      primaryRole = resolvedRoles[0];
    }
  }

  // Fallback to initial role if API returned empty
  if (resolvedRoles.length === 0 && primaryRole) {
    resolvedRoles.push(primaryRole);
  }

  // 2. Concurrently fetch role claims for all resolved roles in parallel
  const allRoleClaims: Claim[] = [];
  const roleClaimsPromises = resolvedRoles.map(async (roleName) => {
    const matchedRoleObj = userRoleObjects.find(
      (r) => r.name && r.name.toLowerCase() === roleName.toLowerCase()
    );
    const roleIdToPass = matchedRoleObj?.id ? String(matchedRoleObj.id) : roleName;
    return fetchAndCacheRoleClaims(roleIdToPass, roleName);
  });

  const roleClaimsResults = await Promise.allSettled(roleClaimsPromises);
  roleClaimsResults.forEach((res) => {
    if (res.status === 'fulfilled' && Array.isArray(res.value)) {
      res.value.forEach((rc) => {
        const norm = normalizeClaim(rc);
        allRoleClaims.push(norm);
        if (norm.claimType) {
          mergedClaims[norm.claimType] = norm.claimValue || 'all';
        }
      });
    }
  });

  if (allRoleClaims.length > 0) {
    mergedClaims.role_claims = allRoleClaims;
  }

  // 3. Process user claims
  if (claimsResult.status === 'fulfilled' && Array.isArray(claimsResult.value) && claimsResult.value.length > 0) {
    claimsResult.value.forEach((c) => {
      const norm = normalizeClaim(c);
      const type = (norm.claimType || '').toLowerCase().trim();
      const val = norm.claimValue;
      if (type === 'tenant' && val) {
        tenant = String(val);
        mergedClaims.tenant = String(val);
      } else if ((type === 'tenant_id' || type === 'tenantid') && val !== undefined && val !== null) {
        const parsed = Number(val);
        if (!isNaN(parsed) && isFinite(parsed)) {
          tenant_id = parsed;
          mergedClaims.tenant_id = parsed;
        }
      }
      if (norm.claimType) {
        mergedClaims[norm.claimType] = norm.claimValue;
      }
    });
    mergedClaims.user_claims = claimsResult.value.map(normalizeClaim);
  }

  // 4. Background preload all system roles & role claims for reference (non-blocking)
  preloadAndCacheAllRoleClaims().catch(() => {});

  return {
    roles: resolvedRoles,
    claims: mergedClaims,
    primaryRole,
    tenant,
    tenant_id,
  };
}

/**
 * Preloads and caches all system roles and their respective role claims concurrently.
 */
export async function preloadAndCacheAllRoleClaims(): Promise<void> {
  const roles = await fetchAndCacheSystemRoles();
  await Promise.allSettled(
    roles.map((role) => fetchAndCacheRoleClaims(role.id || role.Id || '', role.name || role.Name || ''))
  );
}

/**
 * Retrieves all system claims in the identity management system.
 * Any claim is assignable to an authorized user (with admin being a special case).
 */
export async function getSystemClaims(): Promise<Claim[]> {
  if (inMemorySystemClaims && inMemorySystemClaims.length > 0) {
    return inMemorySystemClaims;
  }

  if (typeof window !== 'undefined') {
    try {
      const raw = localStorage.getItem(LOCAL_STORAGE_SYSTEM_CLAIMS_KEY);
      if (raw) {
        const parsed = JSON.parse(raw);
        if (Array.isArray(parsed) && parsed.length > 0) {
          inMemorySystemClaims = parsed;
          return parsed;
        }
      }
    } catch {}
  }

  const claimsMap = new Map<string, Claim>();

  // 1. Try system claims endpoint directly
  try {
    const res = await apiClient.get<Claim[]>('/v1/api/users/system/claims');
    if (res.data && Array.isArray(res.data)) {
      res.data.forEach((c) => {
        const norm = normalizeClaim(c);
        if (norm.claimType) claimsMap.set(norm.claimType, norm);
      });
    }
  } catch {}

  // 2. Aggregate role claims from all system roles
  try {
    const roles = await fetchAndCacheSystemRoles();
    for (const r of roles) {
      const claims = await fetchAndCacheRoleClaims(r.id || r.Id || '', r.name || r.Name || '');
      claims.forEach((c) => {
        const norm = normalizeClaim(c);
        if (norm.claimType && !claimsMap.has(norm.claimType)) {
          claimsMap.set(norm.claimType, norm);
        }
      });
    }
  } catch {}

  // 3. Ensure all standard defined claims from RBAC specification exist
  ROLE_CLAIM_DEFINITIONS.forEach((def, index) => {
    if (!claimsMap.has(def.claim)) {
      claimsMap.set(def.claim, {
        claimId: index + 1,
        claimType: def.claim,
        claimValue: 'all',
        type: def.claim,
        value: 'all',
      });
    }
  });

  const allClaims = Array.from(claimsMap.values());
  inMemorySystemClaims = allClaims;
  if (typeof window !== 'undefined') {
    try {
      localStorage.setItem(LOCAL_STORAGE_SYSTEM_CLAIMS_KEY, JSON.stringify(allClaims));
    } catch {}
  }

  return allClaims;
}