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

export type WorkStatus =
  | "open"
  | "in_progress"
  | "deferred"
  | "blocked"
  | "completed"
  | "cancelled";

export type WorkPriority = "low" | "normal" | "high" | "urgent";

export type WorkAssignment = {
  kind: "account" | "group" | "role" | "function" | "function_assignment" | "anyone";
  id: string;
  label?: string | null;
};

export type WorkSource = {
  module_id: string;
  resource_type: string;
  resource_id: string;
  revision?: string | null;
  url?: string | null;
  label?: string | null;
};

export type WorkItem = {
  id: string;
  provider_id: string;
  owner_module: string;
  tenant_id: string;
  title: string;
  status: WorkStatus;
  priority: WorkPriority;
  summary?: string | null;
  required_action?: string | null;
  action_url?: string | null;
  due_at?: string | null;
  deferred_until?: string | null;
  assignments: WorkAssignment[];
  sources: WorkSource[];
  provenance: Record<string, unknown>;
  metadata: Record<string, unknown>;
  revision: string;
  etag?: string | null;
  created_at?: string | null;
  updated_at?: string | null;
};

export type WorkProviderDiagnostic = {
  provider_id: string;
  owner_module: string;
  code: string;
  message: string;
};

export type WorkListResponse = {
  items: WorkItem[];
  total: number;
  truncated: boolean;
  diagnostics: WorkProviderDiagnostic[];
};

export type WorkSummary = {
  total: number;
  open: number;
  in_progress: number;
  deferred: number;
  blocked: number;
  overdue: number;
  urgent: number;
  truncated: boolean;
  diagnostics: WorkProviderDiagnostic[];
};

export type TaskCreatePayload = {
  title: string;
  summary?: string | null;
  priority: WorkPriority;
  due_at?: string | null;
  required_action?: string | null;
  action_url?: string | null;
  assignments: WorkAssignment[];
  sources?: WorkSource[];
  provenance?: Record<string, unknown>;
  metadata?: Record<string, unknown>;
  idempotency_key: string;
};

export function listWork(
  settings: ApiSettings,
  filters: {
    statuses?: WorkStatus[];
    priorities?: WorkPriority[];
    providers?: string[];
    modules?: string[];
    q?: string;
    limit?: number;
  } = {}
): Promise<WorkListResponse> {
  const params = new URLSearchParams();
  filters.statuses?.forEach((value) => params.append("status", value));
  filters.priorities?.forEach((value) => params.append("priority", value));
  filters.providers?.forEach((value) => params.append("provider", value));
  filters.modules?.forEach((value) => params.append("owner_module", value));
  if (filters.q) params.set("q", filters.q);
  if (filters.limit) params.set("limit", String(filters.limit));
  const query = params.toString();
  return apiFetch<WorkListResponse>(
    settings,
    `/api/v1/tasks${query ? `?${query}` : ""}`
  );
}

export function loadWorkSummary(settings: ApiSettings): Promise<WorkSummary> {
  return apiFetch<WorkSummary>(settings, "/api/v1/tasks/summary");
}

export function createTask(
  settings: ApiSettings,
  payload: TaskCreatePayload
): Promise<WorkItem> {
  return apiFetch<WorkItem>(settings, "/api/v1/tasks", {
    method: "POST",
    body: JSON.stringify(payload)
  });
}

export function transitionTask(
  settings: ApiSettings,
  task: WorkItem,
  action: "start" | "complete" | "defer" | "reopen" | "cancel",
  deferredUntil?: string | null
): Promise<WorkItem> {
  if (!task.etag) throw new Error("i18n:govoplan-tasks.reason.refresh_required");
  return apiFetch<WorkItem>(settings, `/api/v1/tasks/${task.id}/actions`, {
    method: "POST",
    headers: { "If-Match": task.etag },
    body: JSON.stringify({
      action,
      expected_revision: Number(task.revision),
      deferred_until: deferredUntil || null
    })
  });
}