import { DatabaseInterface, UploadTask } from './types';

export class WebDatabase implements DatabaseInterface {
    private getStorageKey(table: string): string {
        return `memowake_${table}`;
    }

    private getUploadTasksFromStorage(): UploadTask[] {
        const data = localStorage.getItem(this.getStorageKey('upload_tasks'));
        return data ? JSON.parse(data) : [];
    }

    private saveUploadTasks(tasks: UploadTask[]): void {
        localStorage.setItem(this.getStorageKey('upload_tasks'), JSON.stringify(tasks));
    }

    private getAppStateData(): Record<string, string> {
        const data = localStorage.getItem(this.getStorageKey('app_state'));
        return data ? JSON.parse(data) : {};
    }

    private saveAppStateData(state: Record<string, string>): void {
        localStorage.setItem(this.getStorageKey('app_state'), JSON.stringify(state));
    }

    async initUploadTable(): Promise<void> {
        console.log('Initializing web storage tables...');
        // Web端不需要初始化表结构，localStorage会自动处理
    }

    async insertUploadTask(task: Omit<UploadTask, 'created_at'>): Promise<void> {
        console.log('Inserting upload task:', task.uri);
        const tasks = this.getUploadTasksFromStorage();
        const existingIndex = tasks.findIndex(t => t.uri === task.uri);
        const newTask: UploadTask = {
            ...task,
            created_at: Math.floor(Date.now() / 1000)
        };

        if (existingIndex >= 0) {
            tasks[existingIndex] = newTask;
        } else {
            tasks.push(newTask);
        }

        this.saveUploadTasks(tasks);
    }

    async getUploadTaskStatus(uri: string): Promise<UploadTask | null> {
        console.log('Checking upload task status for:', uri);
        const tasks = this.getUploadTasksFromStorage();
        return tasks.find(t => t.uri === uri) || null;
    }

    async updateUploadTaskStatus(uri: string, status: UploadTask['status'], file_id?: string): Promise<void> {
        const tasks = this.getUploadTasksFromStorage();
        const taskIndex = tasks.findIndex(t => t.uri === uri);
        if (taskIndex >= 0) {
            tasks[taskIndex].status = status;
            if (file_id) {
                tasks[taskIndex].file_id = file_id;
            }
            this.saveUploadTasks(tasks);
        }
    }

    async updateUploadTaskProgress(uri: string, progress: number): Promise<void> {
        const tasks = this.getUploadTasksFromStorage();
        const taskIndex = tasks.findIndex(t => t.uri === uri);
        if (taskIndex >= 0) {
            tasks[taskIndex].progress = progress;
            this.saveUploadTasks(tasks);
        }
    }

    async getUploadTasks(): Promise<UploadTask[]> {
        console.log('Fetching all upload tasks... time:', new Date().toLocaleString());
        const tasks = this.getUploadTasksFromStorage();
        return tasks.sort((a, b) => b.created_at - a.created_at);
    }

    async cleanUpUploadTasks(): Promise<void> {
        console.log('Cleaning up completed/failed upload tasks...');
        const tasks = this.getUploadTasksFromStorage();
        const filteredTasks = tasks.filter(t =>
            t.status !== 'success' && t.status !== 'failed' && t.status !== 'skipped'
        );
        this.saveUploadTasks(filteredTasks);
    }

    async getUploadTasksSince(timestamp: number): Promise<UploadTask[]> {
        const tasks = this.getUploadTasksFromStorage();
        const filteredTasks = tasks.filter(t => t.created_at >= timestamp);
        return filteredTasks.sort((a, b) => b.created_at - a.created_at);
    }

    async exist_pending_tasks(): Promise<boolean> {
        const tasks = this.getUploadTasksFromStorage();
        return tasks.some(t => t.status === 'pending' || t.status === 'uploading');
    }

    async filterExistingFiles(fileUris: string[]): Promise<string[]> {
        if (fileUris.length === 0) {
            return [];
        }

        const tasks = this.getUploadTasksFromStorage();
        const successfulUris = new Set(
            tasks.filter(t => t.status === 'success').map(t => t.uri)
        );

        const newFileUris = fileUris.filter(uri => !successfulUris.has(uri));

        console.log(`[WebDB] Total files: ${fileUris.length}, Existing successful files: ${successfulUris.size}, New files to upload: ${newFileUris.length}`);

        return newFileUris;
    }

    async setAppState(key: string, value: string | null): Promise<void> {
        console.log(`Setting app state: ${key} = ${value}`);
        const state = this.getAppStateData();
        if (value === null) {
            delete state[key];
        } else {
            state[key] = value;
        }
        this.saveAppStateData(state);
    }

    async getAppState(key: string): Promise<string | null> {
        const state = this.getAppStateData();
        return state[key] || null;
    }

    async executeSql(sql: string, params: any[] = []): Promise<any> {
        console.warn('SQL execution not supported in web environment:', sql);
        return { error: 'SQL execution not supported in web environment' };
    }
}