summaryrefslogtreecommitdiffstats
path: root/src/models.lisp
blob: 8905ae1ab7cf9c6c9d6b5f06cde5baca02987288 (plain)
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
143
144
145
146
147
(in-package #:cepis)

(defstruct (geo (:copier nil))
  "The CEP's coordinate, when the database has one.

The point is the median of the coordinates of that CEP's addresses, not the
mean: one badly geocoded address 40 km away shifts a mean and does not move a
median.

Always check `geo-precisao' before using the point for distance:

- \"logradouro\": the point is a stretch of street. `geo-raio-m' lands around
  100-150 m. Good for maps and for distance.
- \"localidade\": the CEP is the whole municipality (a city-wide general CEP),
  and the point is its centroid. `geo-raio-m' runs from 7 km to 40 km.
  Computing shipping from this is wrong by tens of kilometres.

`geo-raio-m' is the radius containing 90% of that CEP's addresses. It exists
precisely so that error cannot pass unnoticed. The slot is the JSON's `raio_m'
with Lisp's hyphenation."
  (lat 0.0d0 :type double-float :read-only t)
  (lon 0.0d0 :type double-float :read-only t)
  (raio-m 0 :type integer :read-only t)
  (precisao "" :type string :read-only t))

(defun geo-precise-p (geo)
  "True when the coordinate points at a street, not at a municipality.

Shorthand for (string= (geo-precisao geo) \"logradouro\"), which is the check
to make before using the point to measure distance."
  (string= (geo-precisao geo) "logradouro"))

(defstruct (address (:copier nil))
  "A CEP and everything the database knows about it.

Fields the database does not have for that CEP come back as empty strings,
never NIL — that is what the API returns, and changing it here would create a
difference between reading the JSON and reading this library.

`address-geo' is the exception: it is NIL when there is no coordinate. There
the difference is real, because the API omits the whole field in that case
(about 43% of CEPs) rather than sending null.

`address-raw' holds the response exactly as it arrived, as the hash table the
JSON parser produced, so a field the API grows before this library is updated
is not lost."
  (cep "" :type string :read-only t)
  (logradouro "" :type string :read-only t)
  (complemento "" :type string :read-only t)
  (unidade "" :type string :read-only t)
  (bairro "" :type string :read-only t)
  (localidade "" :type string :read-only t)
  (uf "" :type string :read-only t)
  (estado "" :type string :read-only t)
  (regiao "" :type string :read-only t)
  (ibge "" :type string :read-only t)
  (gia "" :type string :read-only t)
  (ddd "" :type string :read-only t)
  (siafi "" :type string :read-only t)
  (geo nil :type (or null geo) :read-only t)
  (raw nil :type (or null hash-table) :read-only t))

(defun address-formatted-cep (address)
  "The CEP with its mask: \"01001-000\".

The native contract always returns it unmasked; formatting is presentation,
and it lives here so it does not become a repeated format string in every
project that uses this."
  (let ((cep (address-cep address)))
    (if (= (length cep) 8)
        (format nil "~a-~a" (subseq cep 0 5) (subseq cep 5))
        cep)))

(defstruct (health (:copier nil))
  "The response of GET /health.

Good for two things: checking that the API answers, and knowing which version
of the database is live. The DNE database changes every two weeks;
`health-dne' identifies it."
  (status "" :type string :read-only t)
  (dne "" :type string :read-only t)
  (ceps 0 :type integer :read-only t)
  (geo 0 :type integer :read-only t)
  (base-gerada-em "" :type string :read-only t))

(defun health-ok-p (health)
  "True when the API reports itself healthy."
  (string= (health-status health) "ok"))

(defun json-string (table key)
  "The value of KEY in TABLE as a string, or \"\" when it is absent or not a scalar."
  (let ((value (gethash key table)))
    (cond ((stringp value) value)
          ((integerp value) (format nil "~d" value))
          ((realp value) (princ-to-string value))
          (t ""))))

(defun json-integer (table key)
  "The value of KEY in TABLE as an integer, or 0 when it is absent or not a number."
  (let ((value (gethash key table)))
    (if (realp value) (round value) 0)))

(defun geo-from-json (value)
  "Build a `geo' from the parsed \"geo\" block, or NIL when it is absent or malformed.

A malformed block yields NIL rather than propagating the error: it is not
worth losing the whole address over, since the rest of the response is still
useful."
  (when (hash-table-p value)
    (let ((lat (gethash "lat" value))
          (lon (gethash "lon" value))
          (raio-m (gethash "raio_m" value))
          (precisao (gethash "precisao" value)))
      (when (and (realp lat) (realp lon) (realp raio-m) (stringp precisao))
        (make-geo :lat (coerce lat 'double-float)
                  :lon (coerce lon 'double-float)
                  :raio-m (round raio-m)
                  :precisao precisao)))))

(defun address-from-json (data)
  "Build an `address' from the hash table the JSON parser produced.

Unknown fields are ignored during construction but preserved in
`address-raw'. A new field in the API therefore cannot break this library."
  (make-address :cep (json-string data "cep")
                :logradouro (json-string data "logradouro")
                :complemento (json-string data "complemento")
                :unidade (json-string data "unidade")
                :bairro (json-string data "bairro")
                :localidade (json-string data "localidade")
                :uf (json-string data "uf")
                :estado (json-string data "estado")
                :regiao (json-string data "regiao")
                :ibge (json-string data "ibge")
                :gia (json-string data "gia")
                :ddd (json-string data "ddd")
                :siafi (json-string data "siafi")
                :geo (geo-from-json (gethash "geo" data))
                :raw data))

(defun health-from-json (data)
  "Build a `health' from the hash table the JSON parser produced."
  (make-health :status (json-string data "status")
               :dne (json-string data "dne")
               :ceps (json-integer data "ceps")
               :geo (json-integer data "geo")
               :base-gerada-em (json-string data "base_gerada_em")))