[Invest] Design ROI Calculation Engine

[NeftaliYagua]

Description

Design and implement a robust Return on Investment (ROI) calculation engine for property investment analysis.

Acceptance Criteria

• Cash flow analysis (rental income vs expenses)
• Cap rate calculation
• Cash-on-cash return
• Internal Rate of Return (IRR)
• Net Present Value (NPV)
• Gross Rent Multiplier (GRM)
• Break-even analysis
• Sensitivity analysis for key variables
• Tax implications modeling
• Configurable assumptions and parameters
• Historical performance tracking
• Comparative investment analysis

Subtasks

• Design investment calculation domain model
• Implement cash flow projection algorithm
• Create cap rate calculator
• Implement IRR calculation (Newton-Raphson method)
• Create NPV calculator with discount rates
• Add tax calculation module
• Implement sensitivity analysis
• Create comparison engine
• Write comprehensive unit tests
• Document calculation methodologies
• Add validation for edge cases

Technical Notes

• Use decimal type for financial calculations
• Implement builder pattern for calculation configuration
• Consider performance for multi-year projections
• Add validation for realistic input ranges
• Reference industry-standard formulas (NAREIT, etc.)