/**
 * FuZip - Gestionnaire d'upload
 * Gère le drag & drop, browse, upload vers API, progression
 */

class UploadManager {
    constructor(side, onStructureLoaded) {
        this.side = side; // 'left' ou 'right'
        this.onStructureLoaded = onStructureLoaded; // Callback quand structure reçue
        this.apiBase = window.FUZIP_CONFIG?.apiBase || '/api/';
        this.i18n = window.FUZIP_CONFIG?.i18n || {};

        // Éléments DOM
        this.panel = document.getElementById(`upload-panel-${side}`); // column-header
        this.column = document.getElementById(`column-${side}`);
        this.dropZone = document.getElementById(`drop-zone-${side}`);
        this.fileInput = document.getElementById(`file-input-${side}`);
        this.btnBrowse = document.getElementById(`btn-browse-${side}`);
        this.panelInfo = document.getElementById(`panel-info-${side}`);
        this.fileName = document.getElementById(`file-name-${side}`);
        this.fileSize = document.getElementById(`file-size-${side}`);
        this.fileCount = document.getElementById(`file-count-${side}`);
        this.progressBar = document.getElementById(`progress-bar-${side}`);
        this.progressFill = document.getElementById(`progress-fill-${side}`);
        this.progressText = document.getElementById(`progress-text-${side}`);
        this.treePanel = document.getElementById(`tree-panel-${side}`);

        // État
        this.currentFile = null;
        this.structure = null;
        this.isUploading = false;

        this.init();
    }

    /**
     * Initialise les événements
     */
    init() {
        // Drag & Drop sur toute la colonne
        if (this.column) {
            this.column.addEventListener('dragover', (e) => this.onDragOver(e));
            this.column.addEventListener('dragleave', (e) => this.onDragLeave(e));
            this.column.addEventListener('drop', (e) => this.onDrop(e));
        }

        // Click sur drop zone pour ouvrir file picker
        if (this.dropZone) {
            this.dropZone.addEventListener('click', () => this.fileInput?.click());
        }

        // Browse button
        if (this.btnBrowse) {
            this.btnBrowse.addEventListener('click', (e) => {
                e.stopPropagation();
                this.fileInput?.click();
            });
        }

        // File input change
        if (this.fileInput) {
            this.fileInput.addEventListener('change', (e) => this.onFileSelected(e));
        }

        // Bouton "Changer"
        const btnChange = document.getElementById(`btn-change-${this.side}`);
        if (btnChange) {
            btnChange.addEventListener('click', () => this.fileInput?.click());
        }

        console.log(`[UploadManager] Initialized for side: ${this.side}`);
    }

    /**
     * Événement dragover
     */
    onDragOver(e) {
        e.preventDefault();
        e.stopPropagation();
        this.column?.classList.add('drag-over');
    }

    /**
     * Événement dragleave
     */
    onDragLeave(e) {
        e.preventDefault();
        e.stopPropagation();
        // Vérifier qu'on quitte vraiment la colonne (pas juste un élément enfant)
        if (!this.column?.contains(e.relatedTarget)) {
            this.column?.classList.remove('drag-over');
        }
    }

    /**
     * Événement drop
     */
    onDrop(e) {
        e.preventDefault();
        e.stopPropagation();
        this.column?.classList.remove('drag-over');

        const files = e.dataTransfer?.files;
        if (files && files.length > 0) {
            this.handleFile(files[0]);
        }
    }

    /**
     * Événement file input change
     */
    onFileSelected(e) {
        const files = e.target?.files;
        if (files && files.length > 0) {
            this.handleFile(files[0]);
        }
    }

    /**
     * Gère un fichier sélectionné
     * @param {File} file
     */
    async handleFile(file) {
        // Validation basique
        if (!file.name.endsWith('.zip')) {
            this.showError(this.i18n.error_not_zip || 'Le fichier doit être un ZIP');
            return;
        }

        if (file.size > 500 * 1024 * 1024) { // 500 MB
            this.showError(this.i18n.error_file_too_large || 'Fichier trop volumineux (max 500 MB)');
            return;
        }

        this.currentFile = file;

        // Upload
        await this.upload();
    }

    /**
     * Upload le fichier vers l'API
     */
    async upload() {
        if (!this.currentFile || this.isUploading) return;

        this.isUploading = true;
        this.panel?.classList.add('uploading');
        this.showProgress(0);

        const formData = new FormData();
        formData.append('file', this.currentFile);
        formData.append('side', this.side);

        try {
            const xhr = new XMLHttpRequest();

            // Progression
            xhr.upload.addEventListener('progress', (e) => {
                if (e.lengthComputable) {
                    const percent = Math.round((e.loaded / e.total) * 100);
                    this.showProgress(percent);
                }
            });

            // Promesse pour gérer le résultat
            const response = await new Promise((resolve, reject) => {
                xhr.addEventListener('load', () => {
                    if (xhr.status >= 200 && xhr.status < 300) {
                        try {
                            const data = JSON.parse(xhr.responseText);
                            resolve(data);
                        } catch (err) {
                            reject(new Error('Réponse JSON invalide'));
                        }
                    } else {
                        reject(new Error(`Erreur HTTP ${xhr.status}`));
                    }
                });

                xhr.addEventListener('error', () => reject(new Error('Erreur réseau')));
                xhr.addEventListener('abort', () => reject(new Error('Upload annulé')));

                xhr.open('POST', `${this.apiBase}upload.php`);
                xhr.send(formData);
            });

            // Succès
            if (response.success) {
                this.structure = response.structure;
                this.showSuccess(response.stats);

                // Callback vers app.js
                if (this.onStructureLoaded) {
                    this.onStructureLoaded(this.side, response.structure, response.stats);
                }
            } else {
                throw new Error(response.error || 'Erreur inconnue');
            }

        } catch (error) {
            console.error(`[UploadManager] Upload error for ${this.side}:`, error);
            this.showError(error.message);
        } finally {
            this.isUploading = false;
            this.panel?.classList.remove('uploading');
        }
    }

    /**
     * Affiche la progression
     * @param {number} percent - 0-100
     */
    showProgress(percent) {
        if (this.progressBar) {
            this.progressBar.classList.remove('hidden');
        }

        if (this.progressFill) {
            this.progressFill.style.width = `${percent}%`;
        }

        if (this.progressText) {
            this.progressText.textContent = `${percent}%`;
        }
    }

    /**
     * Affiche le succès avec stats
     * @param {Object} stats
     */
    showSuccess(stats) {
        this.panel?.classList.remove('error');
        this.panel?.classList.add('success', 'compact');
        this.column?.classList.add('success');

        // Affiche le panel-info
        if (this.panelInfo) {
            this.panelInfo.classList.remove('hidden');
        }

        if (this.fileName) {
            this.fileName.textContent = this.currentFile?.name || '';
        }

        if (this.fileSize) {
            this.fileSize.textContent = this.formatBytes(stats.total_size || 0);
        }

        if (this.fileCount) {
            this.fileCount.textContent = (stats.total_files || 0).toString();
        }

        // Affiche le tree-panel
        if (this.treePanel) {
            this.treePanel.classList.remove('hidden');
        }

        // Cache la progress bar après 1s
        setTimeout(() => {
            this.progressBar?.classList.add('hidden');
        }, 1000);
    }

    /**
     * Affiche une erreur
     * @param {string} message
     */
    showError(message) {
        this.panel?.classList.remove('success');
        this.panel?.classList.add('error');

        alert(message); // TODO: Afficher dans l'UI plutôt qu'une alerte

        // Réinitialise
        this.currentFile = null;
        this.structure = null;
        if (this.panelInfo) {
            this.panelInfo.classList.add('hidden');
        }
        if (this.progressBar) {
            this.progressBar.classList.add('hidden');
        }
    }

    /**
     * Formate les octets en format lisible
     * @param {number} bytes
     * @returns {string}
     */
    formatBytes(bytes) {
        if (bytes === 0) return '0 B';
        const k = 1024;
        const sizes = ['B', 'KB', 'MB', 'GB'];
        const i = Math.floor(Math.log(bytes) / Math.log(k));
        return Math.round(bytes / Math.pow(k, i) * 100) / 100 + ' ' + sizes[i];
    }

    /**
     * Récupère la structure actuelle
     * @returns {Object|null}
     */
    getStructure() {
        return this.structure;
    }

    /**
     * Réinitialise l'upload
     */
    reset() {
        this.currentFile = null;
        this.structure = null;
        this.isUploading = false;

        this.panel?.classList.remove('success', 'error', 'uploading', 'compact');
        this.column?.classList.remove('success', 'error');
        this.panelInfo?.classList.add('hidden');
        this.progressBar?.classList.add('hidden');
        this.treePanel?.classList.add('hidden');

        if (this.fileInput) {
            this.fileInput.value = '';
        }
    }
}

// Export pour utilisation dans app.js
window.UploadManager = UploadManager;