Vue.component('tt-file-upload-light', {
    props: {
        /**
         * Allows multiple files to be selected.
         */
        multiple: {
            type: Boolean,
            default: false
        },
        /**
         * Text for the upload button.
         */
        buttonText: {
            type: String,
            default: 'Datei hochladen'
        },
        /**
         * Optional icon for the upload button.
         */
        buttonIcon: {
            type: String,
            default: 'fas fa-paperclip'
        }
    },
    template: `
        <div class="tt-file-upload-light">
            <!-- Hidden file input, triggered by the button -->
            <input type="file" :multiple="multiple" @change="handleFileSelect" ref="fileInput" style="display: none;"/>

            <!-- The button that users click to select files -->
            <button type="button" class="btn btn-outline-secondary btn-sm" @click="triggerFileInput" :disabled="isUploading">
                <i :class="buttonIcon"></i>
                <span v-if="buttonText" class="ml-1">{{ buttonText }}</span>
            </button>

            <!-- List of files being uploaded or already uploaded -->
            <div v-if="files.length > 0" class="file-list mt-2">
                <div v-for="(file, index) in files" :key="index" class="file-item">
                    <div class="file-info">
                        <i :class="fileIcon(file)" class="file-icon"></i>
                        <span class="file-name">{{ file.file.name }}</span>
                        <span class="file-size">({{ formatSize(file.file.size) }})</span>
                    </div>
                    <div class="file-status">
                        <!-- Progress bar during upload -->
                        <div v-if="file.status === 'uploading'" class="progress" style="height: 10px; width: 100px;">
                            <div class="progress-bar" role="progressbar" :style="{ width: file.progress + '%' }" aria-valuenow="file.progress" aria-valuemin="0" aria-valuemax="100"></div>
                        </div>
                        <!-- Status text -->
                        <span v-if="file.status === 'error'" class="text-danger small">Fehler</span>
                        <span v-if="file.status === 'success'" class="text-success small">Fertig</span>
                        
                        <!-- Remove button -->
                        <button type="button" class="btn btn-link btn-sm text-danger p-0 ml-2" @click="removeFile(index)">
                            <i class="fas fa-times"></i>
                        </button>
                    </div>
                </div>
            </div>
        </div>
    `,
    data() {
        return {
            files: [], // Array to store file wrappers { file, progress, status, response }
            uploadUrl: window.TT_CONFIG['BASE_PATH'] + '/File/upload', // Standard file upload endpoint
        }
    },
    computed: {
        /**
         * Checks if any file is currently being uploaded.
         * @returns {boolean}
         */
        isUploading() {
            return this.files.some(f => f.status === 'uploading');
        }
    },
    methods: {
        /**
         * Programmatically clicks the hidden file input element.
         */
        triggerFileInput() {
            this.$refs.fileInput.click();
        },

        /**
         * Handles the file selection event when the user chooses files.
         * @param {Event} event - The file input change event.
         */
        handleFileSelect(event) {
            const selectedFiles = event.target.files;
            if (!selectedFiles) return;

            // Create a wrapper for each file and start the upload
            Array.from(selectedFiles).forEach(file => {
                const fileWrapper = {
                    file: file,
                    progress: 0,
                    status: 'pending', // Status: pending, uploading, success, error
                    response: null,
                };
                this.files.push(fileWrapper);
                this.uploadFile(fileWrapper);
            });

            // Reset the input value to allow selecting the same file again
            event.target.value = '';
        },

        /**
         * Uploads a single file to the server.
         * @param {object} fileWrapper - The file object wrapper.
         */
        async uploadFile(fileWrapper) {
            const formData = new FormData();
            formData.append('file', fileWrapper.file);
            fileWrapper.status = 'uploading';

            try {
                const response = await axios.post(this.uploadUrl, formData, {
                    onUploadProgress: (progressEvent) => {
                        fileWrapper.progress = Math.round((progressEvent.loaded * 100) / progressEvent.total);
                    }
                });

                fileWrapper.status = 'success';
                fileWrapper.response = response.data;

                // Emit an event with the successful upload data
                this.$emit('uploaded', response.data);
                window.notify('success', `${fileWrapper.file.name} erfolgreich hochgeladen.`);

            } catch (error) {
                fileWrapper.status = 'error';
                console.error('File upload failed:', error);
                window.notify('error', `Upload von ${fileWrapper.file.name} fehlgeschlagen.`);
            }
        },

        /**
         * Public method to reset the component state, clearing all files.
         */
        reset() {
            this.files = [];
        },

        /**
         * Removes a file from the list.
         * @param {number} index - The index of the file to remove.
         */
        removeFile(index) {
            this.files.splice(index, 1);
        },

        /**
         * Formats file size from bytes to a readable string.
         * @param {number} bytes - The file size in bytes.
         * @returns {string}
         */
        formatSize(bytes) {
            if (bytes === 0) return '0 Bytes';
            const k = 1024;
            const sizes = ['Bytes', 'KB', 'MB', 'GB'];
            const i = Math.floor(Math.log(bytes) / Math.log(k));
            return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
        },

        /**
         * Returns a Font Awesome icon class based on the file status.
         * @param {object} file - The file wrapper object.
         * @returns {string}
         */
        fileIcon(file) {
            switch (file.status) {
                case 'uploading': return 'fas fa-spinner fa-spin';
                case 'success': return 'fas fa-check-circle text-success';
                case 'error': return 'fas fa-exclamation-circle text-danger';
                default: return 'fas fa-file-alt';
            }
        }
    }
})