import { apiFetch, apiPath, type ApiSettings } from "@govoplan/core-webui";

export type ViewPolicyScope = "system" | "tenant" | "group" | "user";

export type ViewPolicyItem = {
  allow_view?: boolean;
  allow_select?: boolean;
  allow_assign?: boolean;
  allow_edit?: boolean;
  allow_derive?: boolean;
  allow_workflow_activate?: boolean;
  allowed_view_ids?: string[];
  visible_surface_ids?: string[];
};

export type EffectiveViewPolicy = {
  allow_view: boolean;
  allow_select: boolean;
  allow_assign: boolean;
  allow_edit: boolean;
  allow_derive: boolean;
  allow_workflow_activate: boolean;
  allowed_view_ids?: string[] | null;
  visible_surface_ids?: string[] | null;
};

export type ViewPolicyScopeResponse = {
  scope_type: ViewPolicyScope;
  scope_id?: string | null;
  id?: string | null;
  revision?: number | null;
  policy: ViewPolicyItem;
  effective_policy: EffectiveViewPolicy;
  parent_policy: EffectiveViewPolicy;
  source_path: Array<{
    scope_type: string;
    scope_id?: string | null;
    source_id?: string | null;
    fields?: string[];
  }>;
  diagnostics: Array<Record<string, unknown>>;
};

export type ViewPolicyReferenceData = {
  views: Array<{ id: string; name: string; scope_type?: string }>;
  surfaces: Array<{ id: string; label: string; module_id: string; kind: string }>;
};

export type PolicyImpactCategory = "newly_allowed" | "newly_denied" | "unchanged" | "indeterminate";

export type PolicyImpactPreviewResponse = {
  preview_id: string;
  proposal_hash: string;
  policy_family: string;
  scope_type: string;
  scope_id?: string | null;
  base_revision?: number | null;
  counts: Record<PolicyImpactCategory, number>;
  effects: Array<{
    category: PolicyImpactCategory;
    subject: {
      module_id: string;
      resource_type: string;
      resource_id: string;
      action: string;
      label?: string | null;
      scope_type?: string | null;
      scope_id?: string | null;
    };
    current_allowed?: boolean | null;
    proposed_allowed?: boolean | null;
    rule: string;
    current_sources: Array<{ path: string; label: string }>;
    proposed_sources: Array<{ path: string; label: string }>;
    explanation?: string | null;
  }>;
  populations: Array<{
    provider_id: string;
    state: "complete" | "sampled" | "truncated" | "unavailable";
    returned: number;
    total_available?: number | null;
    explanation?: string | null;
  }>;
  details_hidden: boolean;
  details_explanation?: string | null;
  high_impact: boolean;
};

export function fetchViewPolicy(
  settings: ApiSettings,
  scope: ViewPolicyScope,
  scopeId?: string | null
): Promise<ViewPolicyScopeResponse> {
  return apiFetch(settings, apiPath(`/api/v1/admin/view-policies/${scope}`, {
    scope_id: scopeId || undefined
  }));
}

export function updateViewPolicy(
  settings: ApiSettings,
  scope: ViewPolicyScope,
  scopeId: string | null | undefined,
  policy: ViewPolicyItem,
  impactPreview?: Pick<PolicyImpactPreviewResponse, "preview_id" | "proposal_hash"> | null
): Promise<ViewPolicyScopeResponse> {
  return apiFetch(settings, apiPath(`/api/v1/admin/view-policies/${scope}`, {
    scope_id: scopeId || undefined
  }), {
    method: "PUT",
    body: JSON.stringify({
      policy,
      impact_preview_id: impactPreview?.preview_id,
      impact_proposal_hash: impactPreview?.proposal_hash
    })
  });
}

export function deleteViewPolicy(
  settings: ApiSettings,
  scope: ViewPolicyScope,
  scopeId?: string | null,
  impactPreview?: Pick<PolicyImpactPreviewResponse, "preview_id" | "proposal_hash"> | null
): Promise<ViewPolicyScopeResponse> {
  return apiFetch(settings, apiPath(`/api/v1/admin/view-policies/${scope}`, {
    scope_id: scopeId || undefined,
    impact_preview_id: impactPreview?.preview_id,
    impact_proposal_hash: impactPreview?.proposal_hash
  }), { method: "DELETE" });
}

export function previewViewPolicyImpact(
  settings: ApiSettings,
  scope: ViewPolicyScope,
  scopeId: string | null | undefined,
  policy: ViewPolicyItem,
  population: { viewIds: string[]; surfaceIds: string[] }
): Promise<PolicyImpactPreviewResponse> {
  return apiFetch(settings, "/api/v1/admin/policy-impact/preview", {
    method: "POST",
    body: JSON.stringify({
      policy_family: "view",
      scope_type: scope,
      scope_id: scopeId || null,
      proposed_policy: policy,
      populations: [
        {
          provider_id: "views",
          selector: {
            include_views: true,
            include_surfaces: false,
            view_ids: population.viewIds.slice(0, 500)
          },
          limit: 500
        },
        {
          provider_id: "views",
          selector: {
            include_views: false,
            include_surfaces: true,
            surface_ids: population.surfaceIds.slice(0, 500)
          },
          limit: 500
        }
      ],
      include_details: true
    })
  });
}

export async function fetchViewPolicyReferences(settings: ApiSettings): Promise<ViewPolicyReferenceData> {
  const [definitionResult, surfaceResult] = await Promise.allSettled([
    apiFetch<{ definitions: Array<{ id: string; name: string; scope_type?: string }> }>(
      settings,
      apiPath("/api/v1/views/definitions", { scope_type: "tenant", include_inherited: true })
    ),
    apiFetch<{ surfaces: Array<{ id: string; label: string; module_id: string; kind: string }> }>(
      settings,
      "/api/v1/views/surfaces"
    )
  ]);
  return {
    views: definitionResult.status === "fulfilled" ? definitionResult.value.definitions : [],
    surfaces: surfaceResult.status === "fulfilled" ? surfaceResult.value.surfaces : []
  };
}