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.supplier = {
      /** GET /api/supplier → { suppliers: Supplier[] } */
      list: () => this.#json('GET', '/api/supplier'),
      /** POST /api/supplier → 201 { supplier } */
      create: (body) => this.#json('POST', '/api/supplier', { body }),
      /** PATCH /api/supplier/{id} → { supplier } */
      update: (id, body) => this.#json('PATCH', `/api/supplier/${enc(id)}`, { body }),
      /** DELETE /api/supplier/{id} → 204 */
      delete: (id) => this.#empty('DELETE', `/api/supplier/${enc(id)}`),
      /** GET /api/supplier/{id}/articles?skus=... → { articles: SupplierArticle[] } */
      getArticles: (id, skus) => {
        let query = '';
        if (skus != null) {
          const list = Array.isArray(skus) ? skus : [skus];
          const filtered = list.map((s) => String(s).trim()).filter(Boolean);
          if (filtered.length > 0) {
            query = `?skus=${encodeURIComponent(filtered.join(','))}`;
          }
        }
        return this.#json('GET', `/api/supplier/${enc(id)}/articles${query}`);
      },
    };

    this.warehouse = {
      /** GET /api/warehouse → { warehouses: Warehouse[] } */
      list: () => this.#json('GET', '/api/warehouse'),
      /** GET /api/warehouse/{id} → { warehouse: Warehouse } */
      getById: (id) => this.#json('GET', `/api/warehouse/${enc(id)}`),
      /** POST /api/warehouse → 201 { warehouse: Warehouse } */
      create: (body) => this.#json('POST', '/api/warehouse', { body }),
      /** PATCH /api/warehouse/{id} → 200 { warehouse: Warehouse } */
      update: (id, body) => this.#json('PATCH', `/api/warehouse/${enc(id)}`, { body }),
      /** DELETE /api/warehouse/{id} → 204 */
      delete: (id) => this.#empty('DELETE', `/api/warehouse/${enc(id)}`),
    };

    this.stock = {
      /** POST /api/stock/adjust → 201 { manifest, lines, ledger } */
      adjust: (body) => this.#json('POST', '/api/stock/adjust', { body }),
    };

    this.delivery = {
      /** GET /api/delivery → { deliveries: DeliverySummary[] } */
      list: () => this.#json('GET', '/api/delivery'),
      /** GET /api/delivery/{id} → { delivery: Delivery } */
      get: (id) => this.#json('GET', `/api/delivery/${enc(id)}`),
      /** POST /api/delivery → 201 { delivery: Delivery } */
      create: (body) => this.#json('POST', '/api/delivery', { body }),
      /** PATCH /api/delivery/{id} → { delivery: Delivery } */
      update: (id, body) => this.#json('PATCH', `/api/delivery/${enc(id)}`, { body }),
      /** DELETE /api/delivery/{id} → 204 */
      delete: (id) => this.#empty('DELETE', `/api/delivery/${enc(id)}`),
      /** GET /api/delivery/{id}/file/{fileId} → Blob (full binary content) */
      getFile: (id, fileId, { download = false } = {}) =>
        this.#blob('GET', `/api/delivery/${enc(id)}/file/${enc(fileId)}`, {
          query: download ? { download: 'true' } : undefined,
        }),
      /**
       * POST /api/delivery/parse — multipart/form-data, field "file"
       * Accepts PDF or text files (max 50 MB), detection via mimetype/filename
       * Returns an async generator that yields SSE event objects:
       *   { event: 'status'|'llm_call'|'tool_call'|'usage'|'progress'|'result'|'error', data: object }
       */
      parseSse: async function* (file, { signal } = {}) {
        const formData = new FormData();
        formData.append('file', file, file.name);
        const res = await fetch('/api/delivery/parse', {
          method: 'POST',
          credentials: 'include',
          body: formData,
          signal,
        });
        if (!res.ok) {
          let message = res.statusText;
          try {
            const data = await res.json();
            message = data.error || data.message || message;
          } catch { /* ignore */ }
          const err = new Error(message || `Request failed (${res.status})`);
          err.status = res.status;
          throw err;
        }
        const reader = res.body.getReader();
        const decoder = new TextDecoder();
        let buf = '';
        let currentEvent = 'message';

        const onAbort = () => {
          try {
            reader.cancel();
          } catch { /* ignore */ }
        };
        if (signal) {
          if (signal.aborted) {
            onAbort();
            return;
          }
          signal.addEventListener('abort', onAbort, { once: true });
        }

        try {
          while (true) {
            const { done, value } = await reader.read();
            if (done) break;
            buf += decoder.decode(value, { stream: true });
            const lines = buf.split('\n');
            buf = lines.pop(); // keep incomplete last line
            for (const line of lines) {
              if (line.startsWith('event:')) {
                currentEvent = line.slice(6).trim();
              } else if (line.startsWith('data:')) {
                const raw = line.slice(5).trim();
                let data;
                try { data = JSON.parse(raw); } catch { data = raw; }
                yield { event: currentEvent, data };
                currentEvent = 'message';
              }
              // blank line or comment: reset
            }
          }
        } catch (err) {
          if (signal?.aborted || err.name === 'AbortError') {
            return;
          }
          throw err;
        } finally {
          if (signal) {
            signal.removeEventListener('abort', onAbort);
          }
          try {
            reader.releaseLock();
          } catch { /* ignore */ }
        }
      },
      parsePdfSse(file, opts) {
        return this.parseSse(file, opts);
      },
    };

    this.ledger = {
      /** POST /api/ledger → 201 { ledger: LedgerEntry } */
      add: (body) => this.#json('POST', '/api/ledger', { body }),
      /** GET /api/ledger/manifestarticle/{id} → { ledger: LedgerEntry[] } */
      listByManifestarticleId: (manifestarticleId, transactionType) =>
        this.#json('GET', `/api/ledger/manifestarticle/${enc(manifestarticleId)}`, {
          query: transactionType ? { transaction_type: transactionType } : undefined,
        }),
      /** GET /api/ledger/sku/{sku} → { ledger: LedgerEntry[] } */
      listBySku: (sku, transactionType) =>
        this.#json('GET', `/api/ledger/sku/${enc(sku)}`, {
          query: transactionType ? { transaction_type: transactionType } : undefined,
        }),
      /** GET /api/ledger → { ledger: LedgerEntry[] } */
      list: (query) => this.#json('GET', '/api/ledger', { query }),
    };

    this.quote = {
      /** GET /api/quote → { quotes } */
      list: () => this.#json('GET', '/api/quote'),
      /** GET /api/quote/{id} → { quote } */
      get: (id) => this.#json('GET', `/api/quote/${enc(id)}`),
      /** POST /api/quote → 201 { quote } */
      create: (body) => this.#json('POST', '/api/quote', { body }),
      /** PATCH /api/quote/{id} → { quote } */
      update: (id, body) => this.#json('PATCH', `/api/quote/${enc(id)}`, { body }),
      /** DELETE /api/quote/{id} → 204 */
      delete: (id) => this.#empty('DELETE', `/api/quote/${enc(id)}`),
    };

    this.order = {
      /** GET /api/order → { orders } */
      list: () => this.#json('GET', '/api/order'),
      /** GET /api/order/{id} → { order } */
      get: (id) => this.#json('GET', `/api/order/${enc(id)}`),
      /** POST /api/order → 201 { order } */
      create: (body) => this.#json('POST', '/api/order', { body }),
      /** PATCH /api/order/{id} → { order } */
      update: (id, body) => this.#json('PATCH', `/api/order/${enc(id)}`, { body }),
      /** DELETE /api/order/{id} → 204 */
      delete: (id) => this.#empty('DELETE', `/api/order/${enc(id)}`),
    };

    this.customergroup = {
      /** GET /api/customergroup → { customergroups: { id, name, sort, editable }[] } */
      list: () => this.#json('GET', '/api/customergroup'),
      /** POST /api/customergroup body { name } → 201 { customergroup: { id, name, sort } } */
      create: (body) => this.#json('POST', '/api/customergroup', { body }),
      /** PATCH /api/customergroup/{id} body { name } → { customergroup: { id, name, sort } } */
      update: (id, body) =>
        this.#json('PATCH', `/api/customergroup/${enc(id)}`, { body }),
      /** PUT /api/customergroup/order body { customergroupIds } → { customergroupIds } */
      order: (body) => this.#json('PUT', '/api/customergroup/order', { body }),
      /** DELETE /api/customergroup/{id} → 204 */
      delete: (id) => this.#empty('DELETE', `/api/customergroup/${enc(id)}`),
    };

    this.entity = {
      /** GET /api/entity → { entities } · optional query customergroupId */
      list: (query) => this.#json('GET', '/api/entity', { query }),
      /** GET /api/entity/{id} → { entity } */
      get: (id) => this.#json('GET', `/api/entity/${enc(id)}`),
      /** POST /api/entity → 201 { entity } */
      create: (body) => this.#json('POST', '/api/entity', { body }),
      /** PATCH /api/entity/{id} → { entity } */
      update: (id, body) => this.#json('PATCH', `/api/entity/${enc(id)}`, { body }),
      /** DELETE /api/entity/{id} → 204 */
      delete: (id) => this.#empty('DELETE', `/api/entity/${enc(id)}`),
      /** GET /api/entity/next-number → { number: string } */
      nextNumber: () => this.#json('GET', '/api/entity/next-number'),
      /** GET /api/entity/{entityId}/address → { addresses } */
      listAddresses: (entityId) =>
        this.#json('GET', `/api/entity/${enc(entityId)}/address`),
      /** POST /api/entity/{entityId}/address → 201 { address } */
      createAddress: (entityId, body) =>
        this.#json('POST', `/api/entity/${enc(entityId)}/address`, { body }),
      /** PATCH /api/entity/{entityId}/address/{id} → { address } */
      updateAddress: (entityId, id, body) =>
        this.#json('PATCH', `/api/entity/${enc(entityId)}/address/${enc(id)}`, {
          body,
        }),
      /** DELETE /api/entity/{entityId}/address/{id} → 204 */
      deleteAddress: (entityId, id) =>
        this.#empty('DELETE', `/api/entity/${enc(entityId)}/address/${enc(id)}`),
      /** GET /api/entity/{entityId}/contact → { contacts } */
      listContacts: (entityId) =>
        this.#json('GET', `/api/entity/${enc(entityId)}/contact`),
      /** POST /api/entity/{entityId}/contact → 201 { contact } */
      createContact: (entityId, body) =>
        this.#json('POST', `/api/entity/${enc(entityId)}/contact`, { body }),
      /** PATCH /api/entity/{entityId}/contact/{id} → { contact } */
      updateContact: (entityId, id, body) =>
        this.#json('PATCH', `/api/entity/${enc(entityId)}/contact/${enc(id)}`, {
          body,
        }),
      /** DELETE /api/entity/{entityId}/contact/{id} → 204 */
      deleteContact: (entityId, id) =>
        this.#empty('DELETE', `/api/entity/${enc(entityId)}/contact/${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/${enc(sku)}`),
      /** GET /api/article/{sku}/history → { history: [{ id, date, text }, ...] } */
      history: (sku) => this.#json('GET', `/api/article/${enc(sku)}/history`),
      /**
       * Load history and refetch on SSE `article-<sku>`.
       * Paginates in StorageManager until the HTTP API supports skip/offset.
       * `onHistory(history, total)` — returns `{ unwatch, setSkipAndOffset }`.
       */
      historyWatch: (sku, onHistory) => this.watchArticleHistory(sku, onHistory),
      /** PATCH /api/article/{sku} — body: at least one of { name, unitamount, unitSi } */
      update: async (sku, body) => {
        const nameChange = body != null && Object.hasOwn(body, 'name');
        if (nameChange) {
          this.setArticleIndexName(sku, body.name);
          this.setArticleName(sku, body.name);
        }
        try {
          const res = await this.#json('PATCH', `/api/article/${enc(sku)}`, { body });
          this.setArticle(res.article);
          return res;
        } catch (err) {
          if (nameChange) {
            this.clearArticleIndex();
            if (this.getArticle(sku)) {
              void this.loadArticle(sku).catch(() => {});
            }
          }
          throw err;
        }
      },
      /** DELETE /api/article/{sku} */
      delete: (sku) => this.#empty('DELETE', `/api/article/${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/${enc(sku)}/categories`, { body }),
      /** GET /api/article/{sku}/supplier */
      getSuppliers: (sku) => this.#json('GET', `/api/article/${enc(sku)}/supplier`),
      /** POST /api/article/{sku}/supplier */
      addSupplier: (sku, body) =>
        this.#json('POST', `/api/article/${enc(sku)}/supplier`, { body }),
      /** PATCH /api/article/{sku}/supplier/{id} */
      updateSupplier: (sku, id, body) =>
        this.#json('PATCH', `/api/article/${enc(sku)}/supplier/${enc(id)}`, { body }),
      /** PUT /api/article/{sku}/supplier/order */
      orderSuppliers: (sku, body) =>
        this.#json('PUT', `/api/article/${enc(sku)}/supplier/order`, { body }),
      /** DELETE /api/article/{sku}/supplier/{id} */
      deleteSupplier: (sku, id) =>
        this.#empty('DELETE', `/api/article/${enc(sku)}/supplier/${enc(id)}`),
    };

    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.number = {
      /** GET /api/number → { numbers: [{ id, type, prefix, padding, next }] } */
      list: () => this.#json('GET', '/api/number'),
      /** PATCH /api/number/{id} — body: { prefix?, padding?, next? } (only present keys patched) */
      update: (id, body) => this.#json('PATCH', `/api/number/${enc(id)}`, { body }),
    };

    this.setting = {
      /** GET /api/company/setting?frontendOnly=1 → { settings: [{ key, value, frontend }] } */
      list: (query) => this.#json('GET', '/api/company/setting', { query }),
      /** GET /api/company/setting/{key} → { setting: { key, value, frontend } } */
      get: (key) => this.#json('GET', `/api/company/setting/${enc(key)}`),
      /** PUT /api/company/setting/{key} body { value, frontend } → { setting: { key, value, frontend } } */
      upsert: (key, body) =>
        this.#json('PUT', `/api/company/setting/${enc(key)}`, { body }),
    };

    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, headers: extraHeaders } = {}) {
    const url = buildPath(path, query);
    const headers = { ...extraHeaders };
    let payload;
    if (body !== undefined) {
      if (typeof FormData !== 'undefined' && body instanceof FormData) {
        payload = body;
      } else if (raw) {
        if (contentType) 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;