From c7643083599e924383e538f2c3bc6d768d335125 Mon Sep 17 00:00:00 2001
From: DyuthiVivek <Dyuthi.Vivek@iiitb.ac.in>
Date: Sun, 30 Jul 2023 21:04:29 +0530
Subject: [PATCH] added fd payout calculator

---
 DOCUMENTATION.md                 |  5 +++++
 ENDPOINTS.md                     | 24 ++++++++++++++++++++++++
 helpers/functions.py             | 10 ++++++++++
 main.py                          | 14 ++++++++++++++
 tasks/fd_payout.py               | 25 +++++++++++++++++++++++++
 validators/request_validators.py |  6 ++++++
 6 files changed, 84 insertions(+)
 create mode 100644 tasks/fd_payout.py

diff --git a/DOCUMENTATION.md b/DOCUMENTATION.md
index 0542f4d..6d15280 100644
--- a/DOCUMENTATION.md
+++ b/DOCUMENTATION.md
@@ -71,3 +71,8 @@ The initial price of the product or service. |
 |                             |                                        | - `interest_rate` (float): The annual interest rate on the savings. |
 |                             |                                        | - `goal_amount ` (float): The desired savings goal amount. |
 |-----------------------------|----------------------------------------|----------------------------------------------------------------------|
+| GET /fd_payout              | Calculate fd payout monthly vs yearly vs cumulative | -  `p` (int): principal                                 |
+|                             |                                        | - `t` (int): term in years                                           |
+|                             |                                        | - `r` (float): rate in decimals                                      |
+|                             |                                        | - `c` (int): number of months after which to compund                 |
+|-----------------------------|----------------------------------------|----------------------------------------------------------------------|
diff --git a/ENDPOINTS.md b/ENDPOINTS.md
index 9a3aeac..198ac9b 100644
--- a/ENDPOINTS.md
+++ b/ENDPOINTS.md
@@ -2306,3 +2306,27 @@ Sample Output
     "total_contributions": 3600,
     "interest_earned": 315.27777777777777
     }```
+
+```
+
+**POST** `/fd_payout`
+- Request body : `p`,
+        `t`,
+        `r`,
+        `c`,
+        
+- Sample output
+```py
+{
+  {
+        "Tag": "fd_payout",
+        "Principal": 1000,
+        "Term (in years)": 2,
+        "Rate (as a decimal)" : 0.04,
+        "Compounding period" : 6,
+        "Payout_monthly": 80,
+        "Payout_yearly": 81,
+        "Payout_cumulative": 82,
+  }
+}
+```
diff --git a/helpers/functions.py b/helpers/functions.py
index acad33d..7740501 100644
--- a/helpers/functions.py
+++ b/helpers/functions.py
@@ -2068,3 +2068,13 @@ def calculate_modified_internal_rate_of_return(ending_cash_flow: float,
                                                 number_of_periods: int):
     mirr = ((ending_cash_flow / initial_cash_flow) ** (1 / number_of_periods)) - 1
     return mirr*100
+
+# Function to calculate fixed deposit payout for monthly, yearly, cumulative based on given compounding period
+def fd_payout(p : float, t : int, r : float, c : int) -> list[int]:
+    c = 12//c
+    interest_monthly = p * t * r
+    amount_yearly = p * ((1 + r/c)**c)
+    interest_yearly = (amount_yearly - p) * t
+    amount_cumulative = p * ((1 + r/c)**(c * t))
+    interest_cumulative = amount_cumulative - p
+    return [round(interest_monthly), round(interest_yearly), round(interest_cumulative)]
diff --git a/main.py b/main.py
index 6382da1..3e48849 100644
--- a/main.py
+++ b/main.py
@@ -1996,3 +1996,17 @@ def saving_goal(request: SavingGoal):
     request.monthly_contributions ,
     request.interest_rate, 
     request.goal_amount )
+
+
+# Endpoint for function fd_payout
+
+@app.post(
+    "/fd_payout",
+    tags=["fd_payout"],
+    description="Calculate monthly, yearly and cumulative fixed deposit payout",
+)
+def fd_payout(
+    request: FdPayout
+):
+    return fd_payout(request.p, request.t, request.r, request.c)
+
diff --git a/tasks/fd_payout.py b/tasks/fd_payout.py
new file mode 100644
index 0000000..209d700
--- /dev/null
+++ b/tasks/fd_payout.py
@@ -0,0 +1,25 @@
+def fd_payout(
+    p : float, t : int, r : float, c : int
+):
+    
+    '''
+    Calculate fixed deposit 
+    Inputs:  principal, term in years, rate as a decimal, compunding period(compund after how many months)
+    Ouput: fixed deposit payout for monthly, yearly and cumulative compounding 
+    '''
+    try:
+        payout = functions.fd_payout(
+            p, t, r, c
+        )
+        return {
+            "Tag": "fd_payout",
+            "Principal": p,
+            "Term (in years)": t,
+            "Rate (as a decimal)" : r,
+            "Compounding period" : c,
+            "Payout_monthly": payout[0],
+            "Payout_yearly": payout[1],
+            "Payout_cumulative": payout[2],
+        }
+    except:
+        return HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR)
diff --git a/validators/request_validators.py b/validators/request_validators.py
index b58f3c4..9a89edd 100644
--- a/validators/request_validators.py
+++ b/validators/request_validators.py
@@ -659,3 +659,9 @@ class ModifiedInternalRateOfReturn(BaseModel):
 	ending_cash_flow: float
 	initial_cash_flow: float
 	number_of_periods: int
+
+class FdPayout(BaseModel):
+    p : int
+    t : int
+    r : float
+    c : int