Moved code around to conform best practices

11 files changed, 240 insertions, 0 deletions

diff --git a/pkg/config/config.go b/pkg/config/config.go
new file mode 100644
index 0000000..f97467a
--- /dev/null
+++ b/pkg/config/config.go
@@ -0,0 +1,55 @@
+package config
+
+import (
+	"net"
+	"os"
+	"regexp"
+
+	"gopkg.in/yaml.v3"
+)
+
+var validToken = regexp.MustCompile(`^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$`)
+
+type Config struct {
+	// Address is the hostname or ip the web server will listen to
+	Address string `yaml:"address",default:"127.0.0.1"`
+	Port    string `yaml:"port",default:"8080"`
+	// Token is the sncf api token
+	Token string `yaml:"token"`
+}
+
+func (c *Config) validate() error {
+	// address
+	if ip := net.ParseIP(c.Address); ip == nil {
+		if _, err := net.LookupIP(c.Address); err != nil {
+			return newInvalidAddressError(c.Address, err)
+		}
+	}
+	// port
+	if _, err := net.LookupPort("tcp", c.Port); err != nil {
+		return newInvalidPortError(c.Port, err)
+	}
+	// token
+	if ok := validToken.MatchString(c.Token); !ok {
+		return newInvalidTokenError(c.Token)
+	}
+	return nil
+}
+
+// LoadFile loads the c from a given file
+func LoadFile(path string) (*Config, error) {
+	var c *Config
+	f, errOpen := os.Open(path)
+	if errOpen != nil {
+		return nil, newOpenError(path, errOpen)
+	}
+	defer f.Close()
+	decoder := yaml.NewDecoder(f)
+	if err := decoder.Decode(&c); err != nil {
+		return nil, newDecodeError(path, err)
+	}
+	if err := c.validate(); err != nil {
+		return nil, err
+	}
+	return c, nil
+}
diff --git a/pkg/config/config_test.go b/pkg/config/config_test.go
new file mode 100644
index 0000000..3904b5d
--- /dev/null
+++ b/pkg/config/config_test.go
@@ -0,0 +1,54 @@
+package config
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestLoadFile(t *testing.T) {
+	// Minimal yaml file
+	minimalConfig := Config{
+		Address: "127.0.0.2",
+		Port:    "8082",
+		Token:   "12345678-9abc-def0-1234-56789abcdef0",
+	}
+
+	// Minimal yaml file with hostname resolving
+	minimalConfigWithResolving := Config{
+		Address: "localhost",
+		Port:    "8082",
+		Token:   "12345678-9abc-def0-1234-56789abcdef0",
+	}
+
+	// Test cases
+	testCases := []struct {
+		name          string
+		input         string
+		expected      *Config
+		expectedError interface{}
+	}{
+		{"Non existant file", "test_data/non-existant", nil, &OpenError{}},
+		{"Invalid file content", "test_data/invalid.yaml", nil, &DecodeError{}},
+		{"Invalid address should fail to load", "test_data/invalid_address.yaml", nil, &InvalidAddressError{}},
+		{"Unresolvable address should fail to load", "test_data/invalid_address_unresolvable.yaml", nil, &InvalidAddressError{}},
+		{"Invalid port should fail to load", "test_data/invalid_port.yaml", nil, &InvalidPortError{}},
+		{"Invalid token should fail to load", "test_data/invalid_token.yaml", nil, &InvalidTokenError{}},
+		{"Minimal config", "test_data/minimal.yaml", &minimalConfig, nil},
+		{"Minimal config with resolving", "test_data/minimal_with_hostname.yaml", &minimalConfigWithResolving, nil},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			valid, err := LoadFile(tc.input)
+			if tc.expectedError != nil {
+				require.Error(t, err)
+				assert.Equalf(t, reflect.TypeOf(err), reflect.TypeOf(tc.expectedError), "Invalid error type. Got %s but expected %s", reflect.TypeOf(err), reflect.TypeOf(tc.expectedError))
+			} else {
+				require.NoError(t, err)
+			}
+			assert.Equal(t, tc.expected, valid, "Invalid value")
+		})
+	}
+}
diff --git a/pkg/config/error.go b/pkg/config/error.go
new file mode 100644
index 0000000..c49b6a9
--- /dev/null
+++ b/pkg/config/error.go
@@ -0,0 +1,92 @@
+package config
+
+import "fmt"
+
+type ErrorType int
+
+// file open configuration file error
+type OpenError struct {
+	path string
+	err  error
+}
+
+func (e *OpenError) Error() string {
+	return fmt.Sprintf("Failed to open configuration file : %s", e.path)
+}
+func (e *OpenError) Unwrap() error { return e.err }
+
+func newOpenError(path string, err error) error {
+	return &OpenError{
+		path: path,
+		err:  err,
+	}
+}
+
+// Yaml configuration file decoding error
+type DecodeError struct {
+	path string
+	err  error
+}
+
+func (e *DecodeError) Error() string {
+	return fmt.Sprintf("Failed to decode configuration file : %s", e.path)
+}
+func (e *DecodeError) Unwrap() error { return e.err }
+
+func newDecodeError(path string, err error) error {
+	return &DecodeError{
+		path: path,
+		err:  err,
+	}
+}
+
+// Invalid address field error
+type InvalidAddressError struct {
+	address string
+	err     error
+}
+
+func (e *InvalidAddressError) Error() string {
+	return fmt.Sprintf("Invalid address %s : it must be a valid ipv4 address, ipv6 address, or resolvable name", e.address)
+}
+func (e *InvalidAddressError) Unwrap() error { return e.err }
+
+func newInvalidAddressError(address string, err error) error {
+	return &InvalidAddressError{
+		address: address,
+		err:     err,
+	}
+}
+
+// Invalid port field error
+type InvalidPortError struct {
+	port string
+	err  error
+}
+
+func (e *InvalidPortError) Error() string {
+	return fmt.Sprintf("Invalid port %s : it must be a valid port number or tcp service name", e.port)
+}
+func (e *InvalidPortError) Unwrap() error { return e.err }
+
+func newInvalidPortError(port string, err error) error {
+	return &InvalidPortError{
+		port: port,
+		err:  err,
+	}
+}
+
+// Invalid token field error
+type InvalidTokenError struct {
+	token string
+}
+
+func (e *InvalidTokenError) Error() string {
+	return fmt.Sprintf("Invalid token %s : it must be an hexadecimal string that lookslike 12345678-9abc-def0-1234-56789abcdef0", e.token)
+}
+
+func newInvalidTokenError(token string) error {
+	return &InvalidTokenError{
+		token: token,
+	}
+}
diff --git a/pkg/config/error_test.go b/pkg/config/error_test.go
new file mode 100644
index 0000000..f9807c1
--- /dev/null
+++ b/pkg/config/error_test.go
@@ -0,0 +1,20 @@
+package config
+
+import "testing"
+
+func TestErrorsCoverage(t *testing.T) {
+	openErr := OpenError{}
+	_ = openErr.Error()
+	_ = openErr.Unwrap()
+	decodeErr := DecodeError{}
+	_ = decodeErr.Error()
+	_ = decodeErr.Unwrap()
+	invalidAddressErr := InvalidAddressError{}
+	_ = invalidAddressErr.Error()
+	_ = invalidAddressErr.Unwrap()
+	invalidPortErr := InvalidPortError{}
+	_ = invalidPortErr.Error()
+	_ = invalidPortErr.Unwrap()
+	invalidTokenErr := InvalidTokenError{}
+	_ = invalidTokenErr.Error()
+}
diff --git a/pkg/config/test_data/invalid.yaml b/pkg/config/test_data/invalid.yaml
new file mode 100644
index 0000000..db1ddad
--- /dev/null
+++ b/pkg/config/test_data/invalid.yaml
@@ -0,0 +1 @@
+blargh(ads)
diff --git a/pkg/config/test_data/invalid_address.yaml b/pkg/config/test_data/invalid_address.yaml
new file mode 100644
index 0000000..e3682b2
--- /dev/null
+++ b/pkg/config/test_data/invalid_address.yaml
@@ -0,0 +1,3 @@
+address: "0.0.0.0.0"
+port: 8082
+token: 12345678-9abc-def0-1234-56789abcdef0
diff --git a/pkg/config/test_data/invalid_address_unresolvable.yaml b/pkg/config/test_data/invalid_address_unresolvable.yaml
new file mode 100644
index 0000000..d476093
--- /dev/null
+++ b/pkg/config/test_data/invalid_address_unresolvable.yaml
@@ -0,0 +1,3 @@
+address: "invalid"
+port: 8082
+token: 12345678-9abc-def0-1234-56789abcdef0
diff --git a/pkg/config/test_data/invalid_port.yaml b/pkg/config/test_data/invalid_port.yaml
new file mode 100644
index 0000000..2790b3f
--- /dev/null
+++ b/pkg/config/test_data/invalid_port.yaml
@@ -0,0 +1,3 @@
+address: localhost
+port: invalid
+token: 12345678-9abc-def0-1234-56789abcdef0
diff --git a/pkg/config/test_data/invalid_token.yaml b/pkg/config/test_data/invalid_token.yaml
new file mode 100644
index 0000000..6f9e297
--- /dev/null
+++ b/pkg/config/test_data/invalid_token.yaml
@@ -0,0 +1,3 @@
+address: 127.0.0.1
+port: 8080
+token: invalid
diff --git a/pkg/config/test_data/minimal.yaml b/pkg/config/test_data/minimal.yaml
new file mode 100644
index 0000000..2944645
--- /dev/null
+++ b/pkg/config/test_data/minimal.yaml
@@ -0,0 +1,3 @@
+address: 127.0.0.2
+port: 8082
+token: 12345678-9abc-def0-1234-56789abcdef0
diff --git a/pkg/config/test_data/minimal_with_hostname.yaml b/pkg/config/test_data/minimal_with_hostname.yaml
new file mode 100644
index 0000000..716b2d5
--- /dev/null
+++ b/pkg/config/test_data/minimal_with_hostname.yaml
@@ -0,0 +1,3 @@
+address: localhost
+port: 8082
+token: 12345678-9abc-def0-1234-56789abcdef0