---
title: "From lease roll to DCF"
output:
  rmarkdown::html_vignette:
    toc: true
vignette: >
  %\VignetteIndexEntry{From lease roll to DCF}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(collapse = TRUE, comment = "#>")
```

## Purpose

This vignette shows how to describe a small office asset from explicit lease
events, then run the standard package workflow without writing YAML manually.

## 1. Build a lease roll

```{r}
library(cre.dcf)

north <- lease_unit(
  "North",
  area_sqm = 1800,
  events = list(
    lease_event(start = 2025, end = 2027, rent = 230, vac = 0.10),
    vacancy_event(start = 2028, end = 2028, capex_sqm = 35),
    renewal_event(start = 2029, end = 2034, rent = 245, free_months = 3, capex_sqm = 20)
  )
)

south <- lease_unit(
  "South",
  area_sqm = 1200,
  events = list(
    lease_event(start = 2025, end = 2034, rent = 210, vac = 0.03)
  )
)

roll <- lease_roll(list(north, south))

north
roll
lease_roll_snapshot(roll)
```

## 2. Turn the lease roll into a deal

```{r}
deal <- deal_spec(
  price = 10e6,
  purchase_year = 2025,
  lease_roll = roll,
  opex_sqm = 18,
  debt = debt_terms(ltv = 0.60, rate = 0.045, type = "bullet")
)

deal
asset_snapshot(deal)
```

## 3. Run the analysis

```{r}
res <- analyze_deal(deal)

asset_snapshot(res)
summary(res)
```

## 4. Read the operating table

```{r}
ops <- deal_cashflows(res, "operating")
cmp <- deal_cashflows(res, "comparison")

ops
cmp
```

The lease roll drives the first operating years directly:

- rent and vacancy shape `gei`,
- `opex_sqm` reduces `noi`,
- vacancy and reletting events can create temporary drops and recoveries,
- the financing layer is then applied on top of that operating profile.