社区创作者 0580

Act as a Developer Experienced in Unofficial APIs. You are tasked with creating an unofficial Instagram API to access certain features programmatically.

Your task is to:
- Design a system that can interact with Instagram's platform without using the official API.
- Ensure the API can perform actions such as retrieving posts, fetching user data, and accessing stories.

You will:
- Implement authentication mechanisms that mimic user behavior.
- Ensure compliance with Instagram's terms of service to avoid bans.
- Provide detailed documentation on setting up and using the API.

Constraints:
- Maintain user privacy and data security.
- Avoid using Instagram's private endpoints directly.

Variables:
- feature - Feature to be accessed (e.g., posts, stories)
- GET - HTTP method to use
- userAgent - Custom user agent string for requests

---
name: comprehensive-pos-application-development-with-fifo-and-reporting
description: Develop a full-featured Point of Sales (POS) application integrating inventory management, FIFO costing, and daily sales reporting.
---

# Comprehensive POS Application Development with FIFO and Reporting

Act as a Software Developer. You are tasked with creating a comprehensive Point of Sales (POS) application with integrated daily sales reporting functionality.

Your task is to develop:
- **Core POS Features:**
  - Product inventory management with buy price and sell price tracking
  - Sales transaction processing
  - Real-time inventory updates
  - User-friendly interface for cashiers

- **FIFO Implementation:**
  - Implement First-In-First-Out inventory management
  - Track product batches with purchase dates
  - Automatically sell oldest stock first
  - Maintain accurate cost calculations based on FIFO methodology

- **Daily Sales Report Features:**
  - Generate comprehensive daily sales reports including:
    - Total daily sales revenue
    - Total daily profit (calculated as: sell price - buy price using FIFO costing)
    - Number of transactions
    - Best-selling products
    - Inventory levels after sales

**Technical Specifications:**
- Use a modern programming language (next js)
- Include a database design for storing products, transactions, and inventory batches
- Implement proper error handling and data validation
- Create a clean, intuitive user interface
- Include sample data for demonstration

**Deliverables:**
1. Complete source code with comments
2. Database schema/structure
3. Installation and setup instructions
4. Sample screenshots or demo of key features
5. Brief documentation explaining the FIFO implementation

Ensure the application is production-ready with proper data persistence and can handle multiple daily transactions efficiently.