# 1. Goal
Calculate the annual premium of a car insurance policy. An insurance program calls the calculation before it sends an offer to a customer. The program needs one premium for each policy.

# 2. Open questions
None.

# 3. Context
- Package $TMP.
- No other objects are required.

# 4. Contract
- Create the class {{P}}INSURANCE_PREMIUM in package $TMP.
- The class is public, final, and has a public constructor without parameters.
- The class has the public type TY_REGION (CHAR 2) and TY_PREMIUM (P LENGTH 8 DECIMALS 2).
- The class has one public method:
  CALCULATE_PREMIUM
    IMPORTING
      iv_age              TYPE i
      iv_power_kw         TYPE i
      iv_region           TYPE ty_region
      iv_claim_free_years TYPE i
    RETURNING
      VALUE(rv_premium)   TYPE ty_premium.
- Do not add other public methods.

# 5. Business rules
Apply the rules in this sequence.
1. Validate the inputs:
   - iv_age must be between 18 and 99.
   - iv_power_kw must be greater than 0.
   - iv_claim_free_years must not be negative.
   - iv_region must be one of the known regions (see rule 2).
   If any check fails, return 0.
2. The base premium depends on the region:
   A1: 150, B2: 200, C3: 250, D4: 300, E5: 350.
3. The age factor:
   - age < 25: 1.5
   - 25 <= age <= 65: 1.0
   - age > 65: 1.2
4. The power factor:
   - power <= 50 kW: 0.9
   - 51 <= power <= 100 kW: 1.0
   - 101 <= power <= 150 kW: 1.3
   - power > 150 kW: 1.6
5. The claim-free discount:
   - Each claim-free year gives a 5% discount.
   - The maximum discount is 30%.
   - The discount factor is 1 minus the discount (e.g., 0 claim-free years: 1.0, 6 or more: 0.7).
6. Calculate the premium:
   premium = base premium * age factor * power factor * discount factor.
   Calculate with full precision and round the final result to 2 decimals.
7. If the rounded premium is less than 100, return 100.
8. Else return the rounded premium.

# 6. Constraints
- Release target: 7.58.
- Coding standards: Clean ABAP. Method length below 40 statements. No global variables. No comment that restates the code. One statement per line.
- Out of scope: do not create other objects.

# 7. Acceptance
- The class is active and has no syntax error.
- The hidden tests pass.
- Write your own ABAP Unit tests for the class.