Vue.component('tt-autocomplete', {
    template: `
        <div class="form-group" :class="{'row': row}">
          <slot name="prepend"></slot>
          <label v-if="label" :for="label" :class="{'col-form-label': row, 'col-sm-4': row, 'col-form-label-sm': sm && row}">{{ label }}</label>
          <div class="autocomplete position-relative" :class="{'col-sm-8 p-0': row}">
            <input
                :id="label"
                v-model="displayValue"
                :placeholder="placeholder"
                :class="{'form-control-sm': sm}"
                :style="{'padding-right': $slots.append ? '30px' : '0'}"
                type="text"
                class="form-control tt-autocomplete"
                autocomplete="off"
                @input="onInput"
                @focus="onFocus"
                @blur="onBlur"
                @keydown.esc="showSuggestions = false"
                @keydown.down.prevent="navigate(1)"
                @keydown.up.prevent="navigate(-1)"
                @keydown.enter.prevent="selectOnEnter"
            />
            <slot name="append"></slot>
            <button v-show="displayValue.length > 0" @click="clear" tabindex="-1" type="button" class="btn btn-link position-absolute" style="right: -5px; top: 50%; transform: translateY(-50%);">
              <i class="fas fa-times"></i>
            </button>

            <ul v-if="showSuggestions" class="dropdown-menu show dropdown-shadow">
              <li v-if="isLoading" class="dropdown-item">
                <div class="spinner-border spinner-border-sm text-primary" role="status"><span class="sr-only">Loading...</span></div>
                Einträge werden geladen...
              </li>
              <template v-if="!isLoading">
                <li v-if="displayValue.length < 3" class="dropdown-item disabled">
                  Bitte mindestens 3 Zeichen eingeben
                </li>
                <li v-if="displayValue.length >= 3 && !displayingItems.length" class="dropdown-item disabled">
                  Keine Suchergebnisse vorhanden.
                </li>
                <li
                    v-for="(item, index) in displayingItems.slice(0, 10)"
                    :key="item.value"
                    :class="{'active': cursor === index}"
                    class="dropdown-item"
                    style="cursor: pointer;"
                    @mousedown.prevent="selectSuggestion(item)"
                >
                  {{ item.text }}
                </li>
                <li v-if="displayingItems.length > 10" class="dropdown-item disabled">
                  Mehr Suchergebnisse vorhanden. Bitte genauer eingeben
                </li>
              </template>
            </ul>
          </div>
        </div>
    `,
    props: {
        value:           {type: [String, Number]},
        label:           {type: String, required: false},
        apiUrl:          String,
        placeholder:     {type: String, default: ''},
        items:           {type: Array, default: () => []},
        sm:              {type: Boolean, default: true},
        row:             {type: Boolean, default: false},
        returnText:      {type: Boolean, default: false},
        caseInsensitive: {type: Boolean, default: false},
    },
    data() {
        return {
            displayValue: '',
            displayingItems: [],
            isLoading: false,
            showSuggestions: false,
            fetchSuggestionsDebounceTimer: null,
            disableValueWatcher: false,
            cursor: -1,
        };
    },
    watch: {
        value: {
            handler(newValue) {
                if (this.disableValueWatcher) return;
                this.updateDisplayValue(newValue);
            },
            immediate: true
        },
        apiUrl: {
            handler: 'fetchSuggestions',
            immediate: true
        },
    },
    methods: {
        async updateDisplayValue(id) {
            if (!id) {
                this.displayValue = '';
                return;
            }

            if (this.returnText && isNaN(id)) {
                this.displayValue = id;
                return;
            }

            if (this.apiUrl) {
                const response = await axios.get(`${this.apiUrl}${this.apiUrl.includes('?') ? '&' : '?'}autocomplete=1&searchedID=${id}`);
                if (response.data[0]) this.displayValue = response.data[0].text;
            } else {
                const selectedItem = this.items.find(item =>
                    this.caseInsensitive ? String(item.value).toLowerCase() === String(id).toLowerCase() : item.value === id
                );
                if (selectedItem) this.displayValue = selectedItem.text;
            }
        },
        onInput() {
            if (!this.apiUrl && this.items.length > 0) {
                const lowerCaseInput = this.displayValue.toLowerCase();
                const matchingItem = this.items.find(item => item.value.toLowerCase() === lowerCaseInput);
                if (matchingItem) {
                    this.selectSuggestion(matchingItem);
                    return;
                }
            }
            if (this.returnText) this.$emit('input', this.displayValue);
            this.fetchSuggestions();
        },
        onFocus() {
            this.showSuggestions = true;
            this.fetchSuggestions();
        },
        onBlur() {
            setTimeout(() => this.showSuggestions = false, 200);
        },
        fetchSuggestions() {
            clearTimeout(this.fetchSuggestionsDebounceTimer);
            if (this.displayValue.length < 3) {
                this.displayingItems = [];
                this.isLoading = false;
                return;
            }

            this.fetchSuggestionsDebounceTimer = setTimeout(() => {
                this.isLoading = true;
                this.cursor = -1;

                if (!this.apiUrl) {
                    const searchTerms = this.displayValue.toLowerCase().split(' ').filter(s => s);
                    this.displayingItems = this.items.filter(item => {
                        const itemText = item.text.toLowerCase();
                        return searchTerms.every(term => itemText.includes(term));
                    });
                    this.isLoading = false;
                    return;
                }

                axios.get(`${this.apiUrl}${this.apiUrl.includes('?') ? '&' : '?'}autocomplete=1&q=${encodeURIComponent(this.displayValue)}`)
                    .then(response => {
                        this.displayingItems = response.data?.status === 'error' ? [] : response.data;
                        if (this.displayingItems.length === 1 && this.displayingItems[0].text === this.displayValue) {
                            this.selectSuggestion(this.displayingItems[0]);
                        }
                    })
                    .finally(() => this.isLoading = false);
            }, 300);
        },
        selectSuggestion(item) {
            this.disableValueWatcher = true;
            this.displayValue = item.text;
            this.$emit('input', item.value);
            this.showSuggestions = false;
            this.$nextTick(() => this.disableValueWatcher = false);
        },
        selectOnEnter() {
            if (this.cursor >= 0 && this.displayingItems[this.cursor])
                this.selectSuggestion(this.displayingItems[this.cursor]);
        },
        navigate(direction) {
            const itemCount = this.displayingItems.slice(0, 10).length;
            if (!itemCount) return;
            this.cursor = (this.cursor + direction + itemCount) % itemCount;
        },
        clear() {
            this.displayValue = '';
            this.$emit('input', '');
            this.displayingItems = [];
        }
    }
});