Added support for global config files

go.mod

@@ -4,4 +4,7 @@ go 1.20
 
 require github.com/arran4/golang-ical v0.0.0-20230213232137-07c6aad5e4f0
 
-require github.com/BurntSushi/toml v1.2.1
+require (
+	github.com/BurntSushi/toml v1.2.1
+	github.com/mitchellh/go-homedir v1.1.0
+)

go.sum

@@ -9,6 +9,8 @@ github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/mitchellh/go-homedir v1.1.0 h1:lukF9ziXFxDFPkA1vsr5zpc1XuPDn/wFntq5mG+4E0Y=
+github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=

main.go

@@ -1,7 +1,9 @@
 package main
 
 import (
+	"errors"
 	"fmt"
+	"io/fs"
 	"log"
 	"net/http"
 	"os"
@@ -12,6 +14,7 @@ import (
 	"github.com/NickyBoy89/assign-notify/selection"
 	"github.com/NickyBoy89/assign-notify/timeline"
 	ics "github.com/arran4/golang-ical"
+	"github.com/mitchellh/go-homedir"
 )
 
 func ConstructCalendarUrl(
@@ -29,7 +32,11 @@ func ConstructCalendarUrl(
 	)
 }
 
-const ConfigFileName = "config.toml"
+// ConfigFileLocations is a list of every place that the config file could be located
+// The items are explored in-order, and tildes are expanded to the user's home directory
+var ConfigFileLocations = []string{
+	"~/.config/assign-notify/config.toml",
+}
 
 type Config struct {
 	MoodleRoot string `toml:"moodle_root"`
@@ -39,14 +46,37 @@ type Config struct {
 
 func main() {
 	// Load the config
+	var configFileLocation string
+	for _, path := range ConfigFileLocations {
+		location, err := homedir.Expand(path)
+		if err != nil {
+			log.Fatalf("Unable to get home directory: %s", err)
+		}
+
+		if _, err := os.Stat(location); err == nil {
+			configFileLocation = location
+		} else {
+			// If there actually was an error, and the file wasn't just missing
+			// Otherwise, check the next file in the list
+			if !errors.Is(err, fs.ErrNotExist) {
+				log.Fatalf("Error accessing config file at %s: %s", location, err)
+			}
+		}
+	}
+
+	// No configuration was found
+	if configFileLocation == "" {
+		log.Fatalf("No configuration file found, looked in: %s", ConfigFileLocations)
+	}
+
 	var conf Config
-	confFile, err := os.Open(ConfigFileName)
+	confFile, err := os.Open(configFileLocation)
 	if err != nil {
-		log.Fatalf("Unable to open config %s: %s", ConfigFileName, err)
+		log.Fatalf("Unable to open config %s: %s", configFileLocation, err)
 	}
 
 	if _, err := toml.NewDecoder(confFile).Decode(&conf); err != nil {
-		log.Fatalf("Error decoding %s: %s", ConfigFileName, err)
+		log.Fatalf("Error decoding %s: %s", configFileLocation, err)
 	}
 	confFile.Close()