function enc(value) {
  return encodeURIComponent(String(value));
}

function buildUrl(baseUrl, path) {
  return new URL(path, baseUrl || window.location.origin).href;
}

function buildPath(path, query) {
  if (!query) return path;
  const params = new URLSearchParams();
  for (const [key, value] of Object.entries(query)) {
    if (value == null) continue;
    params.set(key, String(value));
  }
  const qs = params.toString();
  return qs ? `${path}?${qs}` : path;
}

/**
 * Thin HTTP client for the dashback API (cookie auth, JSON / blob / empty).
 */
export class ApiClient {
  #baseUrl;

  constructor(baseUrl = window.location.origin) {
    this.#baseUrl = baseUrl;

    this.auth = {
      /** POST /api/auth/login */
      login: (body) => this.#json('POST', '/api/auth/login', { body }),
      /** POST /api/auth/logout */
      logout: () => this.#json('POST', '/api/auth/logout'),
      /** GET /api/auth/me */
      me: () => this.#json('GET', '/api/auth/me'),
      /** PUT /api/auth/selected-company */
      selectedCompany: (body) => this.#json('PUT', '/api/auth/selected-company', { body }),
    };

    this.health = {
      /** GET /api/health */
      get: () => this.#json('GET', '/api/health'),
    };

    this.company = {
      /** GET /api/company */
      list: () => this.#json('GET', '/api/company'),
      /** POST /api/company */
      create: (body) => this.#json('POST', '/api/company', { body }),
      /** PUT /api/company/{id} */
      update: (id, body) => this.#json('PUT', `/api/company/${enc(id)}`, { body }),
      /** DELETE /api/company/{id} */
      delete: (id) => this.#empty('DELETE', `/api/company/${enc(id)}`),
    };

    this.unit = {
      /** GET /api/unit */
      list: () => this.#json('GET', '/api/unit'),
      /** PUT /api/unit */
      upsert: (body) => this.#json('PUT', '/api/unit', { body }),
      /** DELETE /api/unit?si=… */
      delete: (si) => this.#empty('DELETE', '/api/unit', { query: { si } }),
    };

    this.brand = {
      /** GET /api/brand */
      list: () => this.#json('GET', '/api/brand'),
      /** PUT /api/brand */
      upsert: (body) => this.#json('PUT', '/api/brand', { body }),
      /** DELETE /api/brand/{id} */
      delete: (id) => this.#empty('DELETE', `/api/brand/${enc(id)}`),
    };

    this.category = {
      /** GET /api/category/tree */
      tree: () => this.#json('GET', '/api/category/tree'),
      /** GET /api/category/export.zip */
      exportZip: () => this.#blob('GET', '/api/category/export.zip'),
      /** POST /api/category */
      create: (body) => this.#json('POST', '/api/category', { body }),
      /** GET /api/category/{id}/articles */
      articles: (id) => this.#json('GET', `/api/category/${enc(id)}/articles`),
      /** PATCH /api/category/{id} */
      update: (id, body) => this.#json('PATCH', `/api/category/${enc(id)}`, { body }),
      /** DELETE /api/category/{id} */
      delete: (id) => this.#empty('DELETE', `/api/category/${enc(id)}`),
      /** PUT /api/category/order */
      order: (body) => this.#json('PUT', '/api/category/order', { body }),
      /** POST /api/category/{id}/image — raw AVIF body */
      addImage: (id, avifBytes) =>
        this.#json('POST', `/api/category/${enc(id)}/image`, {
          body: avifBytes,
          contentType: 'image/avif',
          raw: true,
        }),
      /** DELETE /api/category/{id}/image */
      deleteImage: (id) => this.#json('DELETE', `/api/category/${enc(id)}/image`),
    };

    this.article = {
      /** GET /api/articleIndex */
      index: () => this.#json('GET', '/api/articleIndex'),
      /** POST /api/article */
      create: (body) => this.#json('POST', '/api/article', { body }),
      /** GET /api/article/export.zip */
      exportZip: (query = {}) => this.#blob('GET', '/api/article/export.zip', { query }),
      /** GET /api/article/{sku} */
      get: (sku) => this.#json('GET', `/api/article/${enc(sku)}`),
      /** PATCH /api/article/{sku} */
      update: (sku, body) => this.#json('PATCH', `/api/article/${enc(sku)}`, { body }),
      /** DELETE /api/article/{sku} */
      delete: (sku) => this.#empty('DELETE', `/api/article/${enc(sku)}`),
      /** PUT /api/article/{sku}/prices */
      setPrices: (sku, body) => this.#json('PUT', `/api/article/${enc(sku)}/prices`, { body }),
      /** POST /api/article/{sku}/image — raw AVIF body */
      addImage: (sku, avifBytes) =>
        this.#json('POST', `/api/article/${enc(sku)}/image`, {
          body: avifBytes,
          contentType: 'image/avif',
          raw: true,
        }),
      /** DELETE /api/article/{sku}/image/{fullHash} */
      deleteImage: (sku, fullHash) =>
        this.#empty('DELETE', `/api/article/${enc(sku)}/image/${enc(fullHash)}`),
      /** PUT /api/article/{sku}/images/order */
      orderImages: (sku, body) =>
        this.#json('PUT', `/api/article/${enc(sku)}/images/order`, { body }),
      /** PUT /api/article/{sku}/eans */
      setEans: (sku, body) => this.#json('PUT', `/api/article/${enc(sku)}/eans`, { body }),
      /** PUT /api/article/{sku}/brand */
      setBrand: (sku, body) => this.#json('PUT', `/api/article/${enc(sku)}/brand`, { body }),
      /** PUT /api/article/{sku}/weight */
      setWeight: (sku, body) => this.#json('PUT', `/api/article/${enc(sku)}/weight`, { body }),
      /** PUT /api/article/{sku}/categories */
      setCategories: (sku, body) =>
        this.#json('PUT', `/api/article/${enc(sku)}/categories`, { body }),
    };

    this.posterminal = {
      /** GET /api/posterminal */
      list: () => this.#json('GET', '/api/posterminal'),
      /** PUT /api/posterminal */
      upsert: (body) => this.#json('PUT', '/api/posterminal', { body }),
      /** DELETE /api/posterminal/{id} */
      delete: (id) => this.#empty('DELETE', `/api/posterminal/${enc(id)}`),
      /** PUT /api/posterminal/{id}/category/{categoryId} */
      setOn: (id, categoryId) =>
        this.#json('PUT', `/api/posterminal/${enc(id)}/category/${enc(categoryId)}`),
      /** DELETE /api/posterminal/{id}/category/{categoryId} */
      setOff: (id, categoryId) =>
        this.#json('DELETE', `/api/posterminal/${enc(id)}/category/${enc(categoryId)}`),
      /** PUT /api/posterminal/{id}/all */
      setOnAll: (id) => this.#json('PUT', `/api/posterminal/${enc(id)}/all`),
      /** DELETE /api/posterminal/{id}/all */
      setOffAll: (id) => this.#json('DELETE', `/api/posterminal/${enc(id)}/all`),
    };

    this.image = {
      /** GET /api/image/{fullHash} → AVIF blob */
      get: (fullHash) => this.#blob('GET', `/api/image/${enc(fullHash)}`),
      /** Absolute URL for <img src> (same-origin / cookie auth). */
      url: (fullHash) => buildUrl(this.#baseUrl, `/api/image/${enc(fullHash)}`),
    };

    this.thumb = {
      /** GET /api/thumb/{fullHash} → AVIF blob */
      get: (fullHash) => this.#blob('GET', `/api/thumb/${enc(fullHash)}`),
      /** Absolute URL for <img src> (same-origin / cookie auth). */
      url: (fullHash) => buildUrl(this.#baseUrl, `/api/thumb/${enc(fullHash)}`),
    };
  }

  /** Absolute URL for a same-origin API path (e.g. SSE). */
  urlFor(path) {
    return buildUrl(this.#baseUrl, path);
  }

  async #json(method, path, { body, query, contentType, raw } = {}) {
    const url = buildPath(path, query);
    const headers = {};
    let payload;
    if (body !== undefined) {
      if (raw) {
        headers['Content-Type'] = contentType;
        payload = body;
      } else {
        headers['Content-Type'] = contentType || 'application/json';
        payload = JSON.stringify(body);
      }
    }

    const res = await fetch(url, {
      method,
      headers,
      credentials: 'include',
      body: payload,
    });

    if (!res.ok) {
      let message = res.statusText;
      let data;
      try {
        data = await res.json();
        message = data.error || data.message || message;
      } catch {
        message = (await res.text().catch(() => message)) || message;
      }
      const err = new Error(message || `Request failed (${res.status})`);
      err.status = res.status;
      err.path = url;
      err.method = method;
      err.data = data;
      throw err;
    }
    if (res.status === 204) return null;
    return res.json();
  }

  async #empty(method, path, { query } = {}) {
    await this.#json(method, path, { query });
    return null;
  }

  async #blob(method, path, { query } = {}) {
    const url = buildPath(path, query);
    const res = await fetch(url, {
      method,
      credentials: 'include',
    });

    if (!res.ok) {
      let message = res.statusText;
      let data;
      try {
        data = await res.json();
        message = data.error || data.message || message;
      } catch {
        message = (await res.text().catch(() => message)) || message;
      }
      const err = new Error(message || `Request failed (${res.status})`);
      err.status = res.status;
      err.path = url;
      err.method = method;
      err.data = data;
      throw err;
    }
    return res.blob();
  }
}

export default ApiClient;