import * as React from "react";
import { createComponent } from "reakit-system/createComponent";
import { createHook } from "reakit-system/createHook";
import { useLiveRef } from "reakit-utils/useLiveRef";
import { useForkRef } from "reakit-utils/useForkRef";
import { warning } from "reakit-warning";
import { useUpdateEffect } from "reakit-utils/useUpdateEffect";
import {
  CompositeOptions,
  CompositeHTMLProps,
  useComposite,
} from "../Composite/Composite";
import { COMBOBOX_KEYS } from "./__keys";
import { unstable_ComboboxStateReturn } from "./ComboboxState";
import { getMenuId } from "./__utils/getMenuId";

function getControls(baseId: string, ariaControls?: string) {
  const menuId = getMenuId(baseId);
  if (ariaControls) {
    return `${ariaControls} ${menuId}`;
  }
  return menuId;
}

function getAutocomplete(options: unstable_ComboboxOptions) {
  if (options.list && options.inline) return "both";
  if (options.list) return "list";
  if (options.inline) return "inline";
  return "none";
}

function isFirstItemAutoSelected(
  items: unstable_ComboboxOptions["items"],
  autoSelect: unstable_ComboboxOptions["autoSelect"],
  currentId: unstable_ComboboxOptions["currentId"]
) {
  if (!autoSelect) return false;
  const firstItem = items.find((item) => !item.disabled);
  return currentId && firstItem?.id === currentId;
}

function hasCompletionString(inputValue: string, currentValue?: string) {
  return (
    !!currentValue &&
    currentValue.length > inputValue.length &&
    currentValue.toLowerCase().indexOf(inputValue.toLowerCase()) === 0
  );
}

function getCompletionString(inputValue: string, currentValue?: string) {
  if (!currentValue) return "";
  const index = currentValue.toLowerCase().indexOf(inputValue.toLowerCase());
  return currentValue.slice(index + inputValue.length);
}

function useValue(options: unstable_ComboboxOptions) {
  return React.useMemo(() => {
    if (!options.inline) {
      return options.inputValue;
    }
    const firstItemAutoSelected = isFirstItemAutoSelected(
      options.items,
      options.autoSelect,
      options.currentId
    );
    if (firstItemAutoSelected) {
      if (hasCompletionString(options.inputValue, options.currentValue)) {
        return (
          options.inputValue +
          getCompletionString(options.inputValue, options.currentValue)
        );
      }
      return options.inputValue;
    }
    return options.currentValue || options.inputValue;
  }, [
    options.inline,
    options.inputValue,
    options.autoSelect,
    options.items,
    options.currentId,
    options.currentValue,
  ]);
}

function getFirstEnabledItemId(items: unstable_ComboboxOptions["items"]) {
  return items.find((item) => !item.disabled)?.id;
}

export const unstable_useCombobox = createHook<
  unstable_ComboboxOptions,
  unstable_ComboboxHTMLProps
>({
  name: "Combobox",
  compose: useComposite,
  keys: COMBOBOX_KEYS,

  useOptions({ menuRole = "listbox", hideOnEsc = true, ...options }) {
    return { menuRole, hideOnEsc, ...options };
  },

  useProps(
    options,
    {
      ref: htmlRef,
      onKeyDown: htmlOnKeyDown,
      onKeyPress: htmlOnKeyPress,
      onChange: htmlOnChange,
      onClick: htmlOnClick,
      onBlur: htmlOnBlur,
      "aria-controls": ariaControls,
      ...htmlProps
    }
  ) {
    const ref = React.useRef<HTMLInputElement>(null);
    const [updated, update] = React.useReducer(() => ({}), {});
    const onKeyDownRef = useLiveRef(htmlOnKeyDown);
    const onKeyPressRef = useLiveRef(htmlOnKeyPress);
    const onChangeRef = useLiveRef(htmlOnChange);
    const onClickRef = useLiveRef(htmlOnClick);
    const onBlurRef = useLiveRef(htmlOnBlur);
    const value = useValue(options);
    const hasInsertedTextRef = React.useRef(false);

    // Completion string
    React.useEffect(() => {
      if (!options.inline) return;
      if (!options.autoSelect) return;
      if (!options.currentValue) return;
      if (options.currentId !== getFirstEnabledItemId(options.items)) return;
      if (!hasCompletionString(options.inputValue, options.currentValue)) {
        return;
      }
      const element = ref.current;
      warning(
        !element,
        "Can't auto select combobox because `ref` wasn't passed to the component",
        "See https://reakit.io/docs/combobox"
      );
      element?.setSelectionRange(
        options.inputValue.length,
        options.currentValue.length
      );
    }, [
      updated,
      options.inline,
      options.autoSelect,
      options.currentValue,
      options.inputValue,
      options.currentId,
      options.items,
    ]);

    // Auto select on type
    useUpdateEffect(() => {
      if (
        options.autoSelect &&
        options.items.length &&
        hasInsertedTextRef.current
      ) {
        // If autoSelect is set to true and the last change was a text
        // insertion, we want to automatically focus on the first suggestion.
        // This effect will run both when inputValue changes and when items
        // change so we can also catch async items.
        options.setCurrentId(undefined);
      } else {
        // Without autoSelect, we'll always blur the combobox option and move
        // focus onto the combobox input.
        options.setCurrentId(null);
      }
    }, [
      options.items,
      options.inputValue,
      options.autoSelect,
      options.setCurrentId,
    ]);

    const onKeyDown = React.useCallback(
      (event: React.KeyboardEvent<HTMLInputElement>) => {
        onKeyDownRef.current?.(event);
        // Resets the reference on key down so we can figure it out later on
        // key press.
        hasInsertedTextRef.current = false;
        if (event.defaultPrevented) return;
        if (event.key === "Escape" && options.hideOnEsc) {
          options.hide?.();
        }
      },
      [options.hideOnEsc, options.hide]
    );

    const onKeyPress = React.useCallback(
      (event: React.KeyboardEvent<HTMLInputElement>) => {
        onKeyPressRef.current?.(event);
        // onKeyPress will catch only printable character presses, so we skip
        // text removal and paste.
        hasInsertedTextRef.current = true;
      },
      []
    );

    const onChange = React.useCallback(
      (event: React.ChangeEvent<HTMLInputElement>) => {
        onChangeRef.current?.(event);
        if (event.defaultPrevented) return;
        options.show?.();
        options.setInputValue?.(event.target.value);
        update();
        if (!options.autoSelect || !hasInsertedTextRef.current) {
          // If autoSelect is not set or it's not an insertion of text, focus
          // on the combobox input after changing the value.
          options.setCurrentId?.(null);
        } else {
          // Selects first item
          options.setCurrentId?.(undefined);
        }
      },
      [
        options.show,
        options.autoSelect,
        options.setCurrentId,
        options.setInputValue,
      ]
    );

    const onClick = React.useCallback(
      (event: React.MouseEvent<HTMLInputElement, MouseEvent>) => {
        onClickRef.current?.(event);
        if (event.defaultPrevented) return;
        // https://github.com/reakit/reakit/issues/808
        if (!options.minValueLength || value.length >= options.minValueLength) {
          options.show?.();
        }
        options.setCurrentId?.(null);
        options.setInputValue(value);
      },
      [
        options.show,
        options.setCurrentId,
        options.setInputValue,
        options.minValueLength,
        value,
      ]
    );

    const onBlur = React.useCallback(
      (event: React.FocusEvent<HTMLInputElement>) => {
        onBlurRef.current?.(event);
        if (event.defaultPrevented) return;
        options.setInputValue(value);
      },
      [options.setInputValue, value]
    );

    return {
      ref: useForkRef(ref, useForkRef(options.unstable_referenceRef, htmlRef)),
      role: "combobox",
      autoComplete: "off",
      "aria-controls": getControls(options.baseId, ariaControls),
      "aria-haspopup": options.menuRole,
      "aria-expanded": options.visible,
      "aria-autocomplete": getAutocomplete(options),
      value,
      onKeyDown,
      onKeyPress,
      onChange,
      onClick,
      onBlur,
      ...htmlProps,
    };
  },

  useComposeProps(
    options,
    {
      onKeyUp,
      onKeyDownCapture: htmlOnKeyDownCapture,
      onKeyDown: htmlOnKeyDown,
      ...htmlProps
    }
  ) {
    const compositeHTMLProps = useComposite(options, htmlProps, true);
    const onKeyDownCaptureRef = useLiveRef(htmlOnKeyDownCapture);
    const onKeyDownRef = useLiveRef(htmlOnKeyDown);

    const onKeyDownCapture = React.useCallback(
      (event: React.KeyboardEvent<HTMLInputElement>) => {
        onKeyDownCaptureRef.current?.(event);
        if (event.defaultPrevented) return;
        if (options.menuRole !== "grid") {
          // If menu is a one-dimensional list and there's an option with
          // focus, we don't want Home/End and printable characters to perform
          // actions on the option, only on the combobox input.
          if (event.key === "Home") return;
          if (event.key === "End") return;
        }
        if (event.key.length === 1) return;
        // Composite's onKeyDownCapture will proxy this event to the active
        // item.
        compositeHTMLProps.onKeyDownCapture?.(event);
      },
      [options.menuRole, compositeHTMLProps.onKeyDownCapture]
    );

    const onKeyDown = React.useCallback(
      (event: React.KeyboardEvent<HTMLInputElement>) => {
        onKeyDownRef.current?.(event);
        if (event.defaultPrevented) return;
        const onlyInputHasFocus = options.currentId === null;
        if (!onlyInputHasFocus) return;
        // Do not perform list actions when pressing horizontal arrow keys when
        // focusing the combobox input while no option has focus.
        if (event.key === "ArrowLeft") return;
        if (event.key === "ArrowRight") return;
        if (event.key === "Home") return;
        if (event.key === "End") return;
        if (
          !event.ctrlKey &&
          !event.altKey &&
          !event.shiftKey &&
          !event.metaKey &&
          (event.key === "ArrowUp" ||
            event.key === "ArrowDown" ||
            event.key.length === 1)
        ) {
          // Up/Down arrow keys and printable characters should open the
          // combobox popover.
          options.show?.();
        }
        compositeHTMLProps.onKeyDown?.(event);
      },
      [options.currentId, options.show, compositeHTMLProps.onKeyDown]
    );

    return {
      ...compositeHTMLProps,
      onKeyDownCapture,
      onKeyDown,
      onKeyUp,
    };
  },
});

export const unstable_Combobox = createComponent({
  as: "input",
  memo: true,
  useHook: unstable_useCombobox,
});

export type unstable_ComboboxOptions = CompositeOptions &
  Pick<
    Partial<unstable_ComboboxStateReturn>,
    | "currentValue"
    | "menuRole"
    | "list"
    | "inline"
    | "autoSelect"
    | "visible"
    | "show"
    | "hide"
    | "unstable_referenceRef"
    | "minValueLength"
  > &
  Pick<
    unstable_ComboboxStateReturn,
    "baseId" | "inputValue" | "setInputValue"
  > & {
    /**
     * When enabled, user can hide the combobox popover by pressing
     * <kbd>Esc</kbd> while focusing on the combobox input.
     * @default true
     */
    hideOnEsc?: boolean;
  };

export type unstable_ComboboxHTMLProps = CompositeHTMLProps &
  React.InputHTMLAttributes<any>;

export type unstable_ComboboxProps = unstable_ComboboxOptions &
  unstable_ComboboxHTMLProps;