import type { Project, ProjectInsertDTO, ProjectUpdateDTO } from "@workspace/schema";

interface ApiResponse<T> {
  data: T | null;
  error: string | null;
}

function getBaseUrl(): string {
  const config = useRuntimeConfig();
  return config.public.apiBaseUrl as string;
}

async function request<T>(path: string, options?: RequestInit): Promise<ApiResponse<T>> {
  try {
    const res = await fetch(`${getBaseUrl()}${path}`, {
      headers: { "Content-Type": "application/json" },
      ...options,
    });

    if (!res.ok) {
      const body = await res.json().catch(() => null);
      return { data: null, error: body?.message ?? `HTTP ${res.status}` };
    }

    const data = (await res.json()) as T;
    return { data, error: null };
  } catch (err) {
    return { data: null, error: err instanceof Error ? err.message : "Unknown error" };
  }
}

export function useProjectApi() {
  const NOT_FOUND = -1;

  const projects = ref<Project[]>([]);
  const loading = ref(false);
  const error = ref<string | null>(null);

  async function fetchProjects(): Promise<void> {
    loading.value = true;
    error.value = null;

    const { data, error: err } = await request<Project[]>("/projects");
    if (data) projects.value = data;
    else error.value = err;

    loading.value = false;
  }

  async function createProject(body: Partial<ProjectInsertDTO>): Promise<Project | null> {
    loading.value = true;
    error.value = null;

    const { data, error: err } = await request<Project>("/projects", {
      method: "POST",
      body: JSON.stringify(body),
    });

    if (data) {
      projects.value.push(data);
    } else {
      error.value = err;
    }

    loading.value = false;
    return data;
  }

  async function updateProject(id: string, body: Partial<ProjectUpdateDTO>): Promise<Project | null> {
    loading.value = true;
    error.value = null;

    const { data, error: err } = await request<Project>(`/projects/${id}`, {
      method: "PATCH",
      body: JSON.stringify(body),
    });

    if (data) {
      const idx = projects.value.findIndex(p => p.id === id);
      if (idx !== NOT_FOUND) projects.value[idx] = data;
    } else {
      error.value = err;
    }

    loading.value = false;
    return data;
  }

  async function deleteProject(id: string): Promise<boolean> {
    loading.value = true;
    error.value = null;

    const { error: err } = await request(`/projects/${id}`, { method: "DELETE" });

    if (err) {
      error.value = err;
    } else {
      projects.value = projects.value.filter(p => p.id !== id);
    }

    loading.value = false;
    return !err;
  }

  return { projects, loading, error, fetchProjects, createProject, updateProject, deleteProject };
}