import React, { Fragment, useState, useMemo } from 'react';
import { useDispatch } from 'react-redux';

import { createPayee } from 'loot-core/src/client/actions/queries';
import { useCachedAccounts } from 'loot-core/src/client/data-hooks/accounts';
import { useCachedPayees } from 'loot-core/src/client/data-hooks/payees';
import { getActivePayees } from 'loot-core/src/client/reducers/queries';

import Add from '../../icons/v1/Add';
import { colors } from '../../style';
import { View } from '../common';

import Autocomplete, {
  defaultFilterSuggestion,
  AutocompleteFooter,
  AutocompleteFooterButton,
} from './Autocomplete';

function getPayeeSuggestions(payees, focusTransferPayees, accounts) {
  let activePayees = accounts ? getActivePayees(payees, accounts) : payees;

  if (focusTransferPayees && activePayees) {
    activePayees = activePayees.filter(p => !!p.transfer_acct);
  }

  return activePayees || [];
}

function makeNew(value, rawPayee) {
  if (value === 'new' && !rawPayee.startsWith('new:')) {
    return 'new:' + rawPayee;
  }
  return value;
}

// Convert the fully resolved new value into the 'new' id that can be
// looked up in the suggestions
function stripNew(value) {
  if (typeof value === 'string' && value.startsWith('new:')) {
    return 'new';
  }
  return value;
}

export function PayeeList({
  items,
  getItemProps,
  highlightedIndex,
  embedded,
  inputValue,
  footer,
}) {
  let isFiltered = items.filtered;
  let createNew = null;
  items = [...items];

  // If the "new payee" item exists, create it as a special-cased item
  // with the value of the input so it always shows whatever the user
  // entered
  if (items[0].id === 'new') {
    let [first, ...rest] = items;
    createNew = first;
    items = rest;
  }

  let offset = createNew ? 1 : 0;
  let lastType = null;

  return (
    <View>
      <View
        style={[
          { overflow: 'auto', padding: '5px 0' },
          !embedded && { maxHeight: 175 },
        ]}
      >
        {createNew && (
          <View
            {...(getItemProps ? getItemProps({ item: createNew }) : null)}
            style={{
              flexShrink: 0,
              padding: '6px 9px',
              backgroundColor:
                highlightedIndex === 0 ? colors.n4 : 'transparent',
              borderRadius: embedded ? 4 : 0,
            }}
          >
            <View
              style={{
                display: 'block',
                color: colors.g8,
                borderRadius: 4,
                fontSize: 11,
                fontWeight: 500,
              }}
            >
              <Add
                width={8}
                height={8}
                style={{
                  color: colors.g8,
                  marginRight: 5,
                  display: 'inline-block',
                }}
              />
              Create Payee “{inputValue}”
            </View>
          </View>
        )}

        {items.map((item, idx) => {
          let type = item.transfer_acct ? 'account' : 'payee';
          let title;
          if (type === 'payee' && lastType !== type) {
            title = 'Payees';
          } else if (type === 'account' && lastType !== type) {
            title = 'Transfer To/From';
          }
          let showMoreMessage = idx === items.length - 1 && isFiltered;
          lastType = type;

          return (
            <Fragment key={item.id}>
              {title && (
                <div
                  key={'title-' + idx}
                  style={{
                    color: colors.y9,
                    padding: '4px 9px',
                  }}
                >
                  {title}
                </div>
              )}

              <div
                {...(getItemProps ? getItemProps({ item }) : null)}
                key={item.id}
                style={{
                  backgroundColor:
                    highlightedIndex === idx + offset
                      ? colors.n4
                      : 'transparent',
                  borderRadius: embedded ? 4 : 0,
                  padding: 4,
                  paddingLeft: 20,
                }}
              >
                {item.name}
              </div>

              {showMoreMessage && (
                <div
                  style={{
                    fontSize: 11,
                    padding: 5,
                    color: colors.n5,
                    textAlign: 'center',
                  }}
                >
                  More payees are available, search to find them
                </div>
              )}
            </Fragment>
          );
        })}
      </View>
      {footer}
    </View>
  );
}

export default function PayeeAutocomplete({
  value,
  inputProps,
  showMakeTransfer = true,
  showManagePayees = false,
  defaultFocusTransferPayees = false,
  tableBehavior,
  embedded,
  onUpdate,
  onSelect,
  onManagePayees,
  accounts,
  payees,
  ...props
}) {
  let cachedPayees = useCachedPayees();
  if (!payees) {
    payees = cachedPayees;
  }

  let cachedAccounts = useCachedAccounts();
  if (!accounts) {
    accounts = cachedAccounts;
  }

  let [focusTransferPayees, setFocusTransferPayees] = useState(
    defaultFocusTransferPayees,
  );
  let [rawPayee, setRawPayee] = useState('');
  let hasPayeeInput = !!rawPayee;
  let payeeSuggestions = useMemo(() => {
    const suggestions = getPayeeSuggestions(
      payees,
      focusTransferPayees,
      accounts,
    );

    if (!hasPayeeInput) {
      return suggestions;
    }
    return [{ id: 'new', name: '' }, ...suggestions];
  }, [payees, focusTransferPayees, accounts, hasPayeeInput]);

  let dispatch = useDispatch();

  async function handleSelect(value, rawInputValue) {
    if (tableBehavior) {
      onSelect && onSelect(makeNew(value, rawInputValue));
    } else {
      let create = () => dispatch(createPayee(rawInputValue));

      if (Array.isArray(value)) {
        value = await Promise.all(value.map(v => (v === 'new' ? create() : v)));
      } else {
        if (value === 'new') {
          value = await create();
        }
      }
      onSelect && onSelect(value);
    }
  }

  const [payeeFieldFocused, setPayeeFieldFocused] = useState(false);

  return (
    <Autocomplete
      key={focusTransferPayees ? 'transfers' : 'all'}
      strict={true}
      embedded={embedded}
      value={stripNew(value)}
      suggestions={payeeSuggestions}
      tableBehavior={tableBehavior}
      itemToString={item => {
        if (!item) {
          return '';
        } else if (item.id === 'new') {
          return rawPayee;
        }
        return item.name;
      }}
      focused={payeeFieldFocused}
      inputProps={{
        ...inputProps,
        onBlur: () => {
          setRawPayee('');
          setPayeeFieldFocused(false);
        },
        onFocus: () => setPayeeFieldFocused(true),
        onChange: setRawPayee,
      }}
      onUpdate={(value, inputValue) =>
        onUpdate && onUpdate(makeNew(value, inputValue))
      }
      onSelect={handleSelect}
      getHighlightedIndex={suggestions => {
        if (suggestions.length > 1 && suggestions[0].id === 'new') {
          return 1;
        }
        return 0;
      }}
      filterSuggestions={(suggestions, value) => {
        let filtered = suggestions.filter(suggestion => {
          if (suggestion.id === 'new') {
            return !value || value === '' || focusTransferPayees ? false : true;
          }

          return defaultFilterSuggestion(suggestion, value);
        });

        filtered.sort((p1, p2) => {
          let r1 = p1.name.toLowerCase().startsWith(value.toLowerCase());
          let r2 = p2.name.toLowerCase().startsWith(value.toLowerCase());
          let r1exact = p1.name.toLowerCase() === value.toLowerCase();
          let r2exact = p2.name.toLowerCase() === value.toLowerCase();

          // (maniacal laughter) mwahaHAHAHAHAH
          if (p1.id === 'new') {
            return -1;
          } else if (p2.id === 'new') {
            return 1;
          } else {
            if (r1exact && !r2exact) {
              return -1;
            } else if (!r1exact && r2exact) {
              return 1;
            } else {
              if (r1 === r2) {
                return 0;
              } else if (r1 && !r2) {
                return -1;
              } else {
                return 1;
              }
            }
          }
        });

        let isf = filtered.length > 100;
        filtered = filtered.slice(0, 100);
        filtered.filtered = isf;

        if (filtered.length >= 2 && filtered[0].id === 'new') {
          if (
            filtered[1].name.toLowerCase() === value.toLowerCase() &&
            !filtered[1].transfer_acct
          ) {
            return filtered.slice(1);
          }
        }
        return filtered;
      }}
      renderItems={(items, getItemProps, highlightedIndex, inputValue) => (
        <PayeeList
          items={items}
          getItemProps={getItemProps}
          highlightedIndex={highlightedIndex}
          inputValue={inputValue}
          embedded={embedded}
          footer={
            <AutocompleteFooter embedded={embedded}>
              {showMakeTransfer && (
                <AutocompleteFooterButton
                  title="Make Transfer"
                  style={[
                    showManagePayees && { marginBottom: 5 },
                    focusTransferPayees && {
                      backgroundColor: colors.y8,
                      color: colors.g2,
                      borderColor: colors.y8,
                    },
                  ]}
                  hoveredStyle={
                    focusTransferPayees && {
                      backgroundColor: colors.y8,
                      colors: colors.y2,
                    }
                  }
                  onClick={() => {
                    onUpdate && onUpdate(null);
                    setFocusTransferPayees(!focusTransferPayees);
                  }}
                />
              )}
              {showManagePayees && (
                <AutocompleteFooterButton
                  title="Manage Payees"
                  onClick={() => onManagePayees()}
                />
              )}
            </AutocompleteFooter>
          }
        />
      )}
      {...props}
    />
  );
}