Add apod package

2 files changed, 95 insertions, 0 deletions

diff --git a/apod/json.go b/apod/json.go
new file mode 100644
index 0000000..c6da815
--- /dev/null
+++ b/apod/json.go
@@ -0,0 +1,64 @@
+package apod
+
+import (
+	"encoding/json"
+	"fmt"
+	"regexp"
+
+	"framagit.org/andinus/cetus/pkg/request"
+)
+
+// APOD holds the response from the api. Not every field is returned
+// in every request. Code & Msg should be filled only if the api
+// returns an error, this behaviour was observed and shouldn't be
+// trusted.
+type APOD struct {
+	Copyright      string `json:"copyright"`
+	Date           string `json:"date"`
+	Explanation    string `json:"explanation"`
+	HDURL          string `json:"hdurl"`
+	MediaType      string `json:"media_type"`
+	ServiceVersion string `json:"service_version"`
+	Title          string `json:"title"`
+	URL            string `json:"url"`
+
+	Code int    `json:"code"`
+	Msg  string `json:"msg"`
+}
+
+// UnmarshalJson will take body as input & unmarshal it to res.
+func UnmarshalJson(res *Res, body string) error {
+	err := json.Unmarshal([]byte(body), res)
+	if err != nil {
+		err = fmt.Errorf("json.go: unmarshalling json failed\n%s",
+			err.Error())
+	}
+	return err
+}
+
+// GetJson takes reqInfo as input and returns the body and an error.
+func GetJson(reqInfo map[string]string) (string, error) {
+	var body string
+	var err error
+
+	// This regexp is not perfect and does not guarantee that the
+	// request will not fail because of wrong date, this will
+	// eliminate many wrong dates though.
+	re := regexp.MustCompile("((19|20)\\d\\d)-(0?[1-9]|1[012])-(0?[1-9]|[12][0-9]|3[01])")
+	if !re.MatchString(reqInfo["date"]) {
+		err = fmt.Errorf("json.go: %s does not match format 'YYYY-MM-DD'",
+			reqInfo["date"])
+		return body, err
+	}
+
+	// reqInfo is map[string]string and params is built from it, currently
+	// it takes apiKey and the date from reqInfo to build param. If any
+	// new key/value is added to reqInfo then it must be addded here too,
+	// it won't be sent as param directly.
+	params := make(map[string]string)
+	params["api_key"] = reqInfo["apiKey"]
+	params["date"] = reqInfo["date"]
+
+	body, err = request.GetRes(reqInfo["api"], params)
+	return body, err
+}
diff --git a/apod/randomdate.go b/apod/randomdate.go
new file mode 100644
index 0000000..743b447
--- /dev/null
+++ b/apod/randomdate.go
@@ -0,0 +1,31 @@
+package apod
+
+import (
+	"math/rand"
+	"time"
+)
+
+// RandDate returns a random date between 1995-06-16 & today.
+func RandDate() string {
+	var (
+		min   int64
+		max   int64
+		sec   int64
+		delta int64
+		date  string
+	)
+	min = time.Date(1995, 6, 16, 0, 0, 0, 0, time.UTC).Unix()
+
+	// We are taking max from UTC but it could fail if the
+	// timezone on NASA APOD server is any different. They don't
+	// mention the timezone api server uses so we use UTC & the
+	// probability of this function failing because of this issue
+	// is very low.
+	max = time.Now().UTC().Unix()
+	delta = max - min
+
+	sec = rand.Int63n(delta) + min
+	date = time.Unix(sec, 0).Format("2006-01-02")
+
+	return date
+}