credit-facility-rs 0.1.0

A rust library for modeling credit facilities with time-aware calculations
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142

/// serialization support for facilities
use serde::{Serialize, Deserialize};
use chrono::{DateTime, Utc};
use crate::decimal::{Money, Rate};
use crate::types::{FacilityStatus, FacilityId};
use crate::facility::Facility;
use rust_decimal::Decimal;

/// serializable view of a facility's state
#[derive(Debug, Serialize, Deserialize)]
pub struct FacilityView {
    pub id: FacilityId,
    pub account_number: String,
    pub customer_id: String,
    pub status: FacilityStatus,
    pub origination_date: DateTime<Utc>,
    pub activation_date: Option<DateTime<Utc>>,
    pub financial: FinancialView,
    pub payments: PaymentView,
    pub metadata: MetadataView,
}

#[derive(Debug, Serialize, Deserialize)]
pub struct FinancialView {
    pub original_commitment: Money,
    pub outstanding_principal: Money,
    pub accrued_interest: Money,
    pub accrued_fees: Money,
    pub accrued_penalties: Money,
    pub total_outstanding: Money,
    pub total_disbursed: Money,
    pub interest_rate: Rate,
}

#[derive(Debug, Serialize, Deserialize)]
pub struct PaymentView {
    pub total_principal_paid: Money,
    pub total_interest_paid: Money,
    pub total_fees_paid: Money,
    pub last_payment_date: Option<DateTime<Utc>>,
    pub last_payment_amount: Option<Money>,
    pub next_payment_due: Option<DateTime<Utc>>,
    pub next_payment_amount: Option<Money>,
    pub payment_count: u32,
    pub missed_payment_count: u32,
    pub days_past_due: u32,
}

#[derive(Debug, Serialize, Deserialize)]
pub struct MetadataView {
    pub facility_type: String,
    pub term_months: Option<u32>,
    pub interest_calculation_method: String,
    pub day_count_convention: String,
}

impl FacilityView {
    pub fn from_facility(facility: &Facility) -> Self {
        FacilityView {
            id: facility.id,
            account_number: facility.state.account_number.clone(),
            customer_id: facility.state.customer_id.clone(),
            status: facility.state.status,
            origination_date: facility.state.origination_date,
            activation_date: facility.state.activation_date,
            financial: FinancialView {
                original_commitment: facility.state.original_commitment,
                outstanding_principal: facility.state.outstanding_principal,
                accrued_interest: facility.state.accrued_interest,
                accrued_fees: facility.state.accrued_fees,
                accrued_penalties: facility.state.accrued_penalties,
                total_outstanding: facility.state.total_outstanding(),
                total_disbursed: facility.state.total_disbursed,
                interest_rate: facility.config.financial_terms.interest_rate,
            },
            payments: PaymentView {
                total_principal_paid: (facility.state.total_payments_received - 
                    (facility.state.total_interest_paid + facility.state.total_fees_charged)).max(Money::ZERO),
                total_interest_paid: facility.state.total_interest_paid,
                total_fees_paid: facility.state.total_fees_paid,
                last_payment_date: facility.state.last_payment_date,
                last_payment_amount: facility.state.last_payment_amount,
                next_payment_due: facility.state.next_payment_due,
                next_payment_amount: facility.state.next_payment_amount,
                payment_count: facility.state.payment_count,
                missed_payment_count: facility.state.missed_payment_count,
                days_past_due: facility.state.days_past_due,
            },
            metadata: MetadataView {
                facility_type: format!("{:?}", facility.config.facility_type),
                term_months: facility.config.financial_terms.term_months,
                interest_calculation_method: "DecliningBalance".to_string(),
                day_count_convention: format!("{:?}", facility.config.interest_config.day_count_convention),
            },
        }
    }
    
    /// convert to pretty-printed json string
    pub fn to_json_pretty(&self) -> Result<String, serde_json::Error> {
        serde_json::to_string_pretty(self)
    }
}

/// term loan specific view
#[derive(Debug, Serialize, Deserialize)]
pub struct TermLoanView {
    pub facility: FacilityView,
    pub current_payment_number: u32,
    pub has_amortization_schedule: bool,
}

/// revolving facility specific view
#[derive(Debug, Serialize, Deserialize)]
pub struct RevolvingView {
    pub facility: FacilityView,
    pub credit_limit: Money,
    pub available_credit: Money,
    pub utilization_rate: Rate,
    pub is_in_draw_period: bool,
}

/// open-term loan specific view
#[derive(Debug, Serialize, Deserialize)]
pub struct OpenTermView {
    pub facility: FacilityView,
    pub btc_collateral: Decimal,
    pub btc_price: Money,
    pub collateral_value: Money,
    pub ltv_ratio: Rate,
    pub margin_call_active: bool,
}

/// overdraft specific view
#[derive(Debug, Serialize, Deserialize)]
pub struct OverdraftView {
    pub facility: FacilityView,
    pub overdraft_limit: Money,
    pub buffer_zone: Money,
    pub linked_account_balance: Money,
    pub is_active: bool,
    pub available_funds: Money,
}