Put the functions into seperate files & fix compile time error

Splitting the program into seperate programs will cause the binary
size to double if the end user wants both services. Instead splitting
the functions in seperate files will keep the binary size small for
both services combined & also the program will be maintainable.

5 files changed, 244 insertions, 231 deletions

diff --git a/README.org b/README.org
index d364367..8529fe3 100644
--- a/README.org
+++ b/README.org
@@ -15,10 +15,6 @@ This whole project was changed multiple times, previous versions have had
 support for services like Unsplash Source & Wallhaven. I'm working on this
 because I want my desktop to have a new wallpaper everyday.
 
-*Note*: Services were split because they didn't have much in common and it's
-easier to maintain when they're split. The cetus command that bundled services
-will stay as is so as to not break scripts, it will be dropped in v0.6.
-
 Cetus v0.5 will support NASA Astronomy Picture of the Day & Bing Photo of the
 Day, I may add support for other services later. Both sources are very easy to
 work with, I personally like NASA APOD & fallback to BPOD only when it's not an
diff --git a/cmd/cetus/apod.go b/cmd/cetus/apod.go
new file mode 100644
index 0000000..b99d899
--- /dev/null
+++ b/cmd/cetus/apod.go
@@ -0,0 +1,108 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	"framagit.org/andinus/cetus/pkg/apod"
+	"framagit.org/andinus/cetus/pkg/background"
+)
+
+func execAPOD() {
+	// reqInfo holds all the parameters that needs to be sent with
+	// the request. GetJson() will pack apiKey & date in params
+	// map before sending it to another function. Adding params
+	// here will not change the behaviour of the function, changes
+	// have to be made in GetJson() too.
+	reqInfo := make(map[string]string)
+	reqInfo["api"] = string(*apodAPI)
+	reqInfo["apiKey"] = string(*apodKey)
+	reqInfo["date"] = string(*apodDate)
+
+	if *apodRand {
+		reqInfo["date"] = apod.RandDate()
+	}
+
+	cacheDir := fmt.Sprintf("%s/%s", getCacheDir(), "apod")
+	os.MkdirAll(cacheDir, os.ModePerm)
+
+	// Check if the file is available locally, if it is then don't
+	// download it again and get it from disk
+	var body string
+	file := fmt.Sprintf("%s/%s", cacheDir, reqInfo["date"])
+	if _, err := os.Stat(file); err == nil {
+		data, err := ioutil.ReadFile(file)
+		chkErr(err)
+		body = string(data)
+	} else if os.IsNotExist(err) {
+		body, err = apod.GetJson(reqInfo)
+		chkErr(err)
+
+		// Write body to the cache so that it can be read
+		// later
+		err = ioutil.WriteFile(file, []byte(body), 0644)
+		chkErr(err)
+	} else {
+		chkErr(err)
+	}
+
+	if *apodDump {
+		fmt.Printf(body)
+		os.Exit(0)
+	}
+
+	res := apod.Res{}
+	err := apod.UnmarshalJson(&res, body)
+	chkErr(err)
+
+	// res.Msg will be returned when there is error on user input
+	// or the api server.
+	if len(res.Msg) != 0 {
+		fmt.Printf("Message: %s", res.Msg)
+		os.Exit(1)
+	}
+
+	// If path-only is passed then it will only print the path,
+	// even if quiet is passed. If the user wants the program to
+	// be quiet then path-only shouldn't be passed. If path-only
+	// is not passed & quiet is also not passed then print the
+	// response.
+	//
+	// Path is only printed when the media type is an image
+	// because res.HDURL is empty on non image media type.
+	if *apodPathOnly {
+		fmt.Println(res.HDURL)
+	} else if !*apodQuiet {
+		apod.Print(res)
+	}
+
+	// Proceed only if the command was set because if it was fetch
+	// then it's already finished & should exit now.
+	if os.Args[1] == "fetch" {
+		os.Exit(0)
+	}
+
+	// Try to set background only if the media type is an image.
+	// First it downloads the image to the cache directory and
+	// then tries to set it with feh. If the download fails then
+	// it exits with a non-zero exit code.
+	if res.MediaType != "image" {
+		os.Exit(0)
+	}
+	imgCacheDir := fmt.Sprintf("%s/%s", cacheDir, "background")
+	os.MkdirAll(imgCacheDir, os.ModePerm)
+	imgFile := fmt.Sprintf("%s/%s", imgCacheDir, reqInfo["date"])
+
+	// Check if the file is available locally, if it is
+	// then don't download it again and set it from disk
+	if _, err := os.Stat(imgFile); os.IsNotExist(err) {
+		err = background.Download(imgFile, res.HDURL)
+		chkErr(err)
+	} else {
+		chkErr(err)
+	}
+
+	err = background.Set(imgFile)
+	chkErr(err)
+}
diff --git a/cmd/cetus/bpod.go b/cmd/cetus/bpod.go
new file mode 100644
index 0000000..f308d47
--- /dev/null
+++ b/cmd/cetus/bpod.go
@@ -0,0 +1,135 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"time"
+
+	"framagit.org/andinus/cetus/pkg/background"
+	"framagit.org/andinus/cetus/pkg/bpod"
+)
+
+func execBPOD() {
+	// reqInfo holds all the parameters that needs to be sent with
+	// the request. GetJson() will pack apiKey & date in params
+	// map before sending it to another function. Adding params
+	// here will not change the behaviour of the function, changes
+	// have to be made in GetJson() too.
+	reqInfo := make(map[string]string)
+	reqInfo["api"] = string(*bpodAPI)
+
+	if *bpodRand {
+		reqInfo["random"] = "true"
+	}
+
+	cacheDir := fmt.Sprintf("%s/%s", getCacheDir(), "bpod")
+	os.MkdirAll(cacheDir, os.ModePerm)
+
+	// Check if the file is available locally, if it is then don't
+	// download it again and get it from disk.
+	//
+	// We don't know the bpod date because that will be there in
+	// response & we can't read the response without requesting
+	// it. So this will assume the bpod date to be today's date if
+	// *bpodRand is not set true. If *bpodRand is set true then we
+	// can't assume the date. Also this way too it can cause error
+	// if our assumed date doesn't matches date at the server.
+	var body string
+	var file string
+	var err error
+
+	if !*bpodRand {
+		// If not *bpodRand and the file exists then read from
+		// disk, if the file doesn't exist then get it and
+		// save it to disk.
+		file = fmt.Sprintf("%s/%s", cacheDir, time.Now().UTC().Format("2006-01-02"))
+		if _, err := os.Stat(file); err == nil {
+			data, err := ioutil.ReadFile(file)
+			chkErr(err)
+			body = string(data)
+		} else if os.IsNotExist(err) {
+			body, err = bpod.GetJson(reqInfo)
+			chkErr(err)
+
+			// Write body to the cache so that it can be
+			// read later
+			err = ioutil.WriteFile(file, []byte(body), 0644)
+			chkErr(err)
+		} else {
+			chkErr(err)
+		}
+	} else {
+		// If *bpodRand then get the file and save it to disk
+		// after unmarshal because we don't know the file name
+		// yet
+		body, err = bpod.GetJson(reqInfo)
+		chkErr(err)
+	}
+
+	// Unmarshal before dump because otherwise if we come across
+	// the date for the first time then it would just dump and
+	// exit without saving it to cache. This way we first save it
+	// to cache if *bpodRand is true.
+	res, err := bpod.UnmarshalJson(body)
+	chkErr(err)
+
+	// Correct format
+	res.Url = fmt.Sprintf("%s%s", "https://www.bing.com", res.Url)
+	dt, err := time.Parse("20060102", res.StartDate)
+	chkErr(err)
+	res.StartDate = dt.Format("2006-01-02")
+
+	file = fmt.Sprintf("%s/%s", cacheDir, res.StartDate)
+	if *bpodRand {
+		// Write body to the cache so that it can be read
+		// later
+		err = ioutil.WriteFile(file, []byte(body), 0644)
+		chkErr(err)
+	}
+
+	if *bpodDump {
+		fmt.Printf(body)
+		os.Exit(0)
+	}
+
+	// If path-only is passed then it will only print the path,
+	// even if quiet is passed. If the user wants the program to
+	// be quiet then path-only shouldn't be passed. If path-only
+	// is not passed & quiet is also not passed then print the
+	// response.
+	//
+	// Path is only printed when the media type is an image
+	// because res.HDURL is empty on non image media type.
+	if *bpodPathOnly {
+		fmt.Println(res.Url)
+	} else if !*bpodQuiet {
+		bpod.Print(res)
+	}
+
+	// Proceed only if the command was set because if it was fetch
+	// then it's already finished & should exit now.
+	if os.Args[1] == "fetch" {
+		os.Exit(0)
+	}
+
+	// Try to set background only if the media type is an image.
+	// First it downloads the image to the cache directory and
+	// then tries to set it with feh. If the download fails then
+	// it exits with a non-zero exit code.
+	imgCacheDir := fmt.Sprintf("%s/%s", cacheDir, "background")
+	os.MkdirAll(imgCacheDir, os.ModePerm)
+	imgFile := fmt.Sprintf("%s/%s", imgCacheDir, res.StartDate)
+
+	// Check if the file is available locally, if it is then don't
+	// download it again and set it from disk
+	if _, err := os.Stat(imgFile); os.IsNotExist(err) {
+		err = background.Download(imgFile, res.Url)
+		chkErr(err)
+	} else {
+		chkErr(err)
+	}
+
+	err = background.Set(imgFile)
+	chkErr(err)
+}
diff --git a/cmd/cetus/main.go b/cmd/cetus/main.go
index 2dec6fa..b039f7a 100644
--- a/cmd/cetus/main.go
+++ b/cmd/cetus/main.go
@@ -3,14 +3,9 @@ package main
 import (
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"math/rand"
 	"os"
 	"time"
-
-	"framagit.org/andinus/cetus/pkg/apod"
-	"framagit.org/andinus/cetus/pkg/background"
-	"framagit.org/andinus/cetus/pkg/bpod"
 )
 
 var (
@@ -140,228 +135,6 @@ func getCacheDir() string {
 	return cacheDir
 }
 
-func execAPOD() {
-	// reqInfo holds all the parameters that needs to be sent with
-	// the request. GetJson() will pack apiKey & date in params
-	// map before sending it to another function. Adding params
-	// here will not change the behaviour of the function, changes
-	// have to be made in GetJson() too.
-	reqInfo := make(map[string]string)
-	reqInfo["api"] = string(*apodAPI)
-	reqInfo["apiKey"] = string(*apodKey)
-	reqInfo["date"] = string(*apodDate)
-
-	if *apodRand {
-		reqInfo["date"] = apod.RandDate()
-	}
-
-	cacheDir := fmt.Sprintf("%s/%s", getCacheDir(), "apod")
-	os.MkdirAll(cacheDir, os.ModePerm)
-
-	// Check if the file is available locally, if it is then don't
-	// download it again and get it from disk
-	var body string
-	file := fmt.Sprintf("%s/%s", cacheDir, reqInfo["date"])
-	if _, err := os.Stat(file); err == nil {
-		data, err := ioutil.ReadFile(file)
-		chkErr(err)
-		body = string(data)
-	} else if os.IsNotExist(err) {
-		body, err = apod.GetJson(reqInfo)
-		chkErr(err)
-
-		// Write body to the cache so that it can be read
-		// later
-		err = ioutil.WriteFile(file, []byte(body), 0644)
-		chkErr(err)
-	} else {
-		chkErr(err)
-	}
-
-	if *apodDump {
-		fmt.Printf(body)
-		os.Exit(0)
-	}
-
-	res := apod.Res{}
-	err := apod.UnmarshalJson(&res, body)
-	chkErr(err)
-
-	// res.Msg will be returned when there is error on user input
-	// or the api server.
-	if len(res.Msg) != 0 {
-		fmt.Printf("Message: %s", res.Msg)
-		os.Exit(1)
-	}
-
-	// If path-only is passed then it will only print the path,
-	// even if quiet is passed. If the user wants the program to
-	// be quiet then path-only shouldn't be passed. If path-only
-	// is not passed & quiet is also not passed then print the
-	// response.
-	//
-	// Path is only printed when the media type is an image
-	// because res.HDURL is empty on non image media type.
-	if *apodPathOnly {
-		fmt.Println(res.HDURL)
-	} else if !*apodQuiet {
-		apod.Print(res)
-	}
-
-	// Proceed only if the command was set because if it was fetch
-	// then it's already finished & should exit now.
-	if os.Args[1] == "fetch" {
-		os.Exit(0)
-	}
-
-	// Try to set background only if the media type is an image.
-	// First it downloads the image to the cache directory and
-	// then tries to set it with feh. If the download fails then
-	// it exits with a non-zero exit code.
-	if res.MediaType != "image" {
-		os.Exit(0)
-	}
-	imgCacheDir := fmt.Sprintf("%s/%s", cacheDir, "background")
-	os.MkdirAll(imgCacheDir, os.ModePerm)
-	imgFile := fmt.Sprintf("%s/%s", imgCacheDir, reqInfo["date"])
-
-	// Check if the file is available locally, if it is
-	// then don't download it again and set it from disk
-	if _, err := os.Stat(imgFile); os.IsNotExist(err) {
-		err = background.Download(imgFile, res.HDURL)
-		chkErr(err)
-	} else {
-		chkErr(err)
-	}
-
-	err = background.Set(imgFile)
-	chkErr(err)
-}
-
-func execBPOD() {
-	// reqInfo holds all the parameters that needs to be sent with
-	// the request. GetJson() will pack apiKey & date in params
-	// map before sending it to another function. Adding params
-	// here will not change the behaviour of the function, changes
-	// have to be made in GetJson() too.
-	reqInfo := make(map[string]string)
-	reqInfo["api"] = string(*bpodAPI)
-
-	if *bpodRand {
-		reqInfo["random"] = "true"
-	}
-
-	cacheDir := fmt.Sprintf("%s/%s", getCacheDir(), "bpod")
-	os.MkdirAll(cacheDir, os.ModePerm)
-
-	// Check if the file is available locally, if it is then don't
-	// download it again and get it from disk.
-	//
-	// We don't know the bpod date because that will be there in
-	// response & we can't read the response without requesting
-	// it. So this will assume the bpod date to be today's date if
-	// *bpodRand is not set true. If *bpodRand is set true then we
-	// can't assume the date. Also this way too it can cause error
-	// if our assumed date doesn't matches date at the server.
-	var body string
-	var file string
-	var err error
-
-	if !*bpodRand {
-		// If not *bpodRand and the file exists then read from
-		// disk, if the file doesn't exist then get it and
-		// save it to disk.
-		file = fmt.Sprintf("%s/%s", cacheDir, time.Now().UTC().Format("2006-01-02"))
-		if _, err := os.Stat(file); err == nil {
-			data, err := ioutil.ReadFile(file)
-			chkErr(err)
-			body = string(data)
-		} else if os.IsNotExist(err) {
-			body, err = bpod.GetJson(reqInfo)
-			chkErr(err)
-
-			// Write body to the cache so that it can be
-			// read later
-			err = ioutil.WriteFile(file, []byte(body), 0644)
-			chkErr(err)
-		} else {
-			chkErr(err)
-		}
-	} else {
-		// If *bpodRand then get the file and save it to disk
-		// after unmarshal because we don't know the file name
-		// yet
-		body, err = bpod.GetJson(reqInfo)
-		chkErr(err)
-	}
-
-	// Unmarshal before dump because otherwise if we come across
-	// the date for the first time then it would just dump and
-	// exit without saving it to cache. This way we first save it
-	// to cache if *bpodRand is true.
-	res, err := bpod.UnmarshalJson(body)
-	chkErr(err)
-
-	// Correct format
-	res.Url = fmt.Sprintf("%s%s", "https://www.bing.com", res.Url)
-	dt, err := time.Parse("20060102", res.StartDate)
-	chkErr(err)
-	res.StartDate = dt.Format("2006-01-02")
-
-	file = fmt.Sprintf("%s/%s", cacheDir, res.StartDate)
-	if *bpodRand {
-		// Write body to the cache so that it can be read
-		// later
-		err = ioutil.WriteFile(file, []byte(body), 0644)
-		chkErr(err)
-	}
-
-	if *bpodDump {
-		fmt.Printf(body)
-		os.Exit(0)
-	}
-
-	// If path-only is passed then it will only print the path,
-	// even if quiet is passed. If the user wants the program to
-	// be quiet then path-only shouldn't be passed. If path-only
-	// is not passed & quiet is also not passed then print the
-	// response.
-	//
-	// Path is only printed when the media type is an image
-	// because res.HDURL is empty on non image media type.
-	if *bpodPathOnly {
-		fmt.Println(res.Url)
-	} else if !*bpodQuiet {
-		bpod.Print(res)
-	}
-
-	// Proceed only if the command was set because if it was fetch
-	// then it's already finished & should exit now.
-	if os.Args[1] == "fetch" {
-		os.Exit(0)
-	}
-
-	// Try to set background only if the media type is an image.
-	// First it downloads the image to the cache directory and
-	// then tries to set it with feh. If the download fails then
-	// it exits with a non-zero exit code.
-	imgCacheDir := fmt.Sprintf("%s/%s", cacheDir, "background")
-	os.MkdirAll(imgCacheDir, os.ModePerm)
-	imgFile := fmt.Sprintf("%s/%s", imgCacheDir, res.StartDate)
-
-	// Check if the file is available locally, if it is then don't
-	// download it again and set it from disk
-	if _, err := os.Stat(imgFile); os.IsNotExist(err) {
-		err = background.Download(imgFile, res.Url)
-		chkErr(err)
-	} else {
-		chkErr(err)
-	}
-
-	err = background.Set(imgFile)
-	chkErr(err)
-}
-
 func chkErr(err error) {
 	if err != nil {
 		fmt.Println(err)
diff --git a/pkg/background/set.go b/pkg/background/set.go
index 2badc48..0f7333d 100644
--- a/pkg/background/set.go
+++ b/pkg/background/set.go
@@ -8,6 +8,7 @@ import (
 
 // Set calls feh to set the background
 func Set(path string) error {
+	var err error
 	switch os.Getenv("XDG_CURRENT_DESKTOP") {
 	case "GNOME", "Unity", "Pantheon":
 		path = fmt.Sprintf("%s%s", "file://", path)