import { JsPsych, JsPsychPlugin, ParameterType, TrialType } from "jspsych";

import { version } from "../package.json";

const info = <const>{
  name: "html-button-response",
  version: version,
  parameters: {
    /** The HTML content to be displayed. */
    stimulus: {
      type: ParameterType.HTML_STRING,
      default: undefined,
    },
    /** Labels for the buttons. Each different string in the array will generate a different button. */
    choices: {
      type: ParameterType.STRING,
      default: undefined,
      array: true,
    },
    /**
     * A function that generates the HTML for each button in the `choices` array. The function gets the string and index of the item in the `choices` array and should return valid HTML. If you want to use different markup for each button, you can do that by using a conditional on either parameter. The default parameter returns a button element with the text label of the choice.
     */
    button_html: {
      type: ParameterType.FUNCTION,
      default: function (choice: string, choice_index: number) {
        return `<button class="jspsych-btn">${choice}</button>`;
      },
    },
    /** This string can contain HTML markup. Any content here will be displayed below the stimulus. The intention is that it can be used to provide a reminder about the action the participant is supposed to take (e.g., which key to press). */
    prompt: {
      type: ParameterType.HTML_STRING,
      default: null,
    },
    /** How long to display the stimulus in milliseconds. The visibility CSS property of the stimulus will be set to `hidden` after this time has elapsed. If this is null, then the stimulus will remain visible until the trial ends. */
    stimulus_duration: {
      type: ParameterType.INT,
      default: null,
    },
    /** ow long to wait for the participant to make a response before ending the trial in milliseconds. If the participant fails to make a response before this timer is reached, the participant's response will be recorded as null for the trial and the trial will end. If the value of this parameter is null, the trial will wait for a response indefinitely.  */
    trial_duration: {
      type: ParameterType.INT,
      default: null,
    },
    /** Setting to `'grid'` will make the container element have the CSS property `display: grid` and enable the use of `grid_rows` and `grid_columns`. Setting to `'flex'` will make the container element have the CSS property `display: flex`. You can customize how the buttons are laid out by adding inline CSS in the `button_html` parameter. */
    button_layout: {
      type: ParameterType.STRING,
      default: "grid",
    },
    /**
     * The number of rows in the button grid. Only applicable when `button_layout` is set to `'grid'`. If null, the number of rows will be determined automatically based on the number of buttons and the number of columns.
     */
    grid_rows: {
      type: ParameterType.INT,
      default: 1,
    },
    /**
     * The number of columns in the button grid. Only applicable when `button_layout` is set to `'grid'`. If null, the number of columns will be determined automatically based on the number of buttons and the number of rows.
     */
    grid_columns: {
      type: ParameterType.INT,
      default: null,
    },
    /** If true, then the trial will end whenever the participant makes a response (assuming they make their response before the cutoff specified by the `trial_duration` parameter). If false, then the trial will continue until the value for `trial_duration` is reached. You can set this parameter to `false` to force the participant to view a stimulus for a fixed amount of time, even if they respond before the time is complete. */
    response_ends_trial: {
      type: ParameterType.BOOL,
      default: true,
    },
    /** How long the button will delay enabling in milliseconds. */
    enable_button_after: {
      type: ParameterType.INT,
      default: 0,
    },
  },
  data: {
    /** The response time in milliseconds for the participant to make a response. The time is measured from when the stimulus first appears on the screen until the participant's response. */
    rt: {
      type: ParameterType.INT,
    },
    /** Indicates which button the participant pressed. The first button in the `choices` array is 0, the second is 1, and so on. */
    response: {
      type: ParameterType.INT,
    },
    /** The HTML content that was displayed on the screen. */
    stimulus: {
      type: ParameterType.HTML_STRING,
    },
  },
};

type Info = typeof info;

/**
 * This plugin displays HTML content and records responses generated by button click. The stimulus can be displayed until a response is given, or for a pre-determined amount of time. The trial can be ended automatically if the participant has failed to respond within a fixed length of time. The button itself can be customized using HTML formatting.
 *
 * @author Josh de Leeuw
 * @see {@link https://www.jspsych.org/latest/plugins/html-button-response/ html-button-response plugin documentation on jspsych.org}
 */
class HtmlButtonResponsePlugin implements JsPsychPlugin<Info> {
  static info = info;

  constructor(private jsPsych: JsPsych) {}

  trial(display_element: HTMLElement, trial: TrialType<Info>) {
    // Display stimulus
    const stimulusElement = document.createElement("div");
    stimulusElement.id = "jspsych-html-button-response-stimulus";
    stimulusElement.innerHTML = trial.stimulus;

    display_element.appendChild(stimulusElement);

    // Display buttons
    const buttonGroupElement = document.createElement("div");
    buttonGroupElement.id = "jspsych-html-button-response-btngroup";
    if (trial.button_layout === "grid") {
      buttonGroupElement.classList.add("jspsych-btn-group-grid");
      if (trial.grid_rows === null && trial.grid_columns === null) {
        throw new Error(
          "You cannot set `grid_rows` to `null` without providing a value for `grid_columns`."
        );
      }
      const n_cols =
        trial.grid_columns === null
          ? Math.ceil(trial.choices.length / trial.grid_rows)
          : trial.grid_columns;
      const n_rows =
        trial.grid_rows === null
          ? Math.ceil(trial.choices.length / trial.grid_columns)
          : trial.grid_rows;
      buttonGroupElement.style.gridTemplateColumns = `repeat(${n_cols}, 1fr)`;
      buttonGroupElement.style.gridTemplateRows = `repeat(${n_rows}, 1fr)`;
    } else if (trial.button_layout === "flex") {
      buttonGroupElement.classList.add("jspsych-btn-group-flex");
    }

    for (const [choiceIndex, choice] of trial.choices.entries()) {
      buttonGroupElement.insertAdjacentHTML("beforeend", trial.button_html(choice, choiceIndex));
      const buttonElement = buttonGroupElement.lastChild as HTMLElement;
      buttonElement.dataset.choice = choiceIndex.toString();
      buttonElement.addEventListener("click", () => {
        after_response(choiceIndex);
      });
    }

    display_element.appendChild(buttonGroupElement);

    // Show prompt if there is one
    if (trial.prompt !== null) {
      display_element.insertAdjacentHTML("beforeend", trial.prompt);
    }

    // start time
    var start_time = performance.now();

    // store response
    var response = {
      rt: null,
      button: null,
    };

    // function to end trial when it is time
    const end_trial = () => {
      // gather the data to store for the trial
      var trial_data = {
        rt: response.rt,
        stimulus: trial.stimulus,
        response: response.button,
      };

      // move on to the next trial
      this.jsPsych.finishTrial(trial_data);
    };

    // function to handle responses by the subject
    function after_response(choice) {
      // measure rt
      var end_time = performance.now();
      var rt = Math.round(end_time - start_time);
      response.button = parseInt(choice);
      response.rt = rt;

      // after a valid response, the stimulus will have the CSS class 'responded'
      // which can be used to provide visual feedback that a response was recorded
      stimulusElement.classList.add("responded");

      // disable all the buttons after a response
      for (const button of buttonGroupElement.children) {
        button.setAttribute("disabled", "disabled");
      }

      if (trial.response_ends_trial) {
        end_trial();
      }
    }

    // hide image if timing is set
    if (trial.stimulus_duration !== null) {
      this.jsPsych.pluginAPI.setTimeout(() => {
        stimulusElement.style.visibility = "hidden";
      }, trial.stimulus_duration);
    }

    // disable all the buttons and set a timeout that enables them after a specified delay if timing is set
    if (trial.enable_button_after > 0) {
      var btns = document.querySelectorAll(".jspsych-html-button-response-button button");
      for (var i = 0; i < btns.length; i++) {
        btns[i].setAttribute("disabled", "disabled");
      }
      this.jsPsych.pluginAPI.setTimeout(() => {
        var btns = document.querySelectorAll(".jspsych-html-button-response-button button");
        for (var i = 0; i < btns.length; i++) {
          btns[i].removeAttribute("disabled");
        }
      }, trial.enable_button_after);
    }

    // end trial if time limit is set
    if (trial.trial_duration !== null) {
      this.jsPsych.pluginAPI.setTimeout(end_trial, trial.trial_duration);
    }
  }

  simulate(
    trial: TrialType<Info>,
    simulation_mode,
    simulation_options: any,
    load_callback: () => void
  ) {
    if (simulation_mode == "data-only") {
      load_callback();
      this.simulate_data_only(trial, simulation_options);
    }
    if (simulation_mode == "visual") {
      this.simulate_visual(trial, simulation_options, load_callback);
    }
  }

  private create_simulation_data(trial: TrialType<Info>, simulation_options) {
    const default_data = {
      stimulus: trial.stimulus,
      rt:
        this.jsPsych.randomization.sampleExGaussian(500, 50, 1 / 150, true) +
        trial.enable_button_after,
      response: this.jsPsych.randomization.randomInt(0, trial.choices.length - 1),
    };

    const data = this.jsPsych.pluginAPI.mergeSimulationData(default_data, simulation_options);

    this.jsPsych.pluginAPI.ensureSimulationDataConsistency(trial, data);

    return data;
  }

  private simulate_data_only(trial: TrialType<Info>, simulation_options) {
    const data = this.create_simulation_data(trial, simulation_options);

    this.jsPsych.finishTrial(data);
  }

  private simulate_visual(trial: TrialType<Info>, simulation_options, load_callback: () => void) {
    const data = this.create_simulation_data(trial, simulation_options);

    const display_element = this.jsPsych.getDisplayElement();

    this.trial(display_element, trial);
    load_callback();

    if (data.rt !== null) {
      this.jsPsych.pluginAPI.clickTarget(
        display_element.querySelector(
          `#jspsych-html-button-response-btngroup [data-choice="${data.response}"]`
        ),
        data.rt
      );
    }
  }
}

export default HtmlButtonResponsePlugin;