/*
 * User administration view.
 *
 * UserAdmin owns the user list, its editable controls and the new-user form.
 * The application remains responsible for permissions, routing, breadcrumbs
 * and making the surrounding view visible.
 */

class UserAdmin {
  /**
   * goal   : Connect the user administration controls to the wiki API.
   * pre    : api performs authenticated requests; translate resolves UI keys;
   *          the user administration form and list exist in the document.
   * post   : Submitting the new-user form creates a user and reloads the list.
   * result : A directly usable controller for the user administration view.
   */
  constructor(api, translate) {
    this.api = api;
    this.translate = translate;
    this.form = document.getElementById("new-user-form");
    this.list = document.getElementById("user-list");

    this.form.addEventListener("submit", (event) => {
      this.#createUser(event).catch((error) => console.error(error));
    });
  }

  /**
   * goal   : Refresh the editable user list from the server.
   * pre    : The current session has administrator permission.
   * post   : Every current user has editable identity, role and password fields.
   * result : A promise that resolves when all rows have been rendered.
   * internals: The API supplies public user records. #renderUser creates each
   *            row and connects its save and delete operations to that record.
   */
  async load() {
    const result = await this.api("/api/admin/users");
    this.list.replaceChildren();
    for (const user of result.users) {
      this.list.append(this.#renderUser(user));
    }
  }

  /** Create a user from the dedicated form and reload the canonical list. */
  async #createUser(event) {
    event.preventDefault();
    const username = document.getElementById("new-username").value;
    await this.api("/api/admin/users", {
      method: "POST",
      body: JSON.stringify({
        username,
        displayName: document.getElementById("new-display-name").value || username,
        email: document.getElementById("new-email").value,
        password: document.getElementById("new-password").value,
        role: document.getElementById("new-role").value,
        enabled: true
      })
    });
    this.form.reset();
    await this.load();
  }

  /** Build one editable user row and connect its actions. */
  #renderUser(user) {
    const row = document.createElement("div");
    row.className = "user-row";

    const username = document.createElement("strong");
    username.textContent = user.username;

    const displayName = document.createElement("input");
    displayName.value = user.displayName;

    const email = document.createElement("input");
    email.type = "email";
    email.value = user.email || "";
    email.placeholder = this.translate("email-address", "Email address");

    const role = this.#roleSelect(user.role);

    const enabled = document.createElement("input");
    enabled.type = "checkbox";
    enabled.checked = user.enabled;

    const password = document.createElement("input");
    password.type = "password";
    password.placeholder = this.translate("new-password", "New password");
    password.autocomplete = "new-password";

    const save = document.createElement("button");
    save.textContent = this.translate("save", "Save");
    save.addEventListener("click", () => {
      this.#updateUser(user, displayName, email, role, enabled, password)
        .catch((error) => console.error(error));
    });

    const remove = document.createElement("button");
    remove.textContent = this.translate("delete", "Delete");
    remove.className = "danger";
    remove.addEventListener("click", () => {
      this.#deleteUser(user).catch((error) => console.error(error));
    });

    const actions = document.createElement("div");
    actions.append(save, remove);
    row.append(username, displayName, email, role, enabled, password, actions);
    return row;
  }

  /** Build the translated role selector for one user row. */
  #roleSelect(selectedRole) {
    const select = document.createElement("select");
    for (const roleName of ["reader", "editor", "admin"]) {
      const option = document.createElement("option");
      option.value = roleName;
      option.textContent = this.translate(`role-${roleName}`, roleName);
      option.selected = roleName === selectedRole;
      select.append(option);
    }
    return select;
  }

  /** Store the current controls of one user row. */
  async #updateUser(user, displayName, email, role, enabled, password) {
    await this.api(`/api/admin/users/${user.id}`, {
      method: "PUT",
      body: JSON.stringify({
        displayName: displayName.value,
        email: email.value,
        role: role.value,
        enabled: enabled.checked,
        password: password.value || undefined
      })
    });
    password.value = "";
  }

  /** Confirm and remove one user, then reload the canonical list. */
  async #deleteUser(user) {
    const question = this.translate("delete-user-confirm", "Delete user {username}?")
      .replace("{username}", user.username);
    if (!window.confirm(question)) return;
    await this.api(`/api/admin/users/${user.id}`, { method: "DELETE" });
    await this.load();
  }
}

export { UserAdmin };