Merge pull request #29 from merschformann/merschformann/request-external-tzs

Adds support for explicit TZ conversion requests

Author: merschformann

README.md

@@ -37,7 +37,7 @@ Show arbitrary time:
 gotz 21
 ```
 
-![preview](material/screenshot/gotz-15.png)
+![preview](material/screenshot/gotz-15-1.png)
 
 Show arbitrary time using different timezone (index based):
 
@@ -47,6 +47,14 @@ gotz 15@2
 
 ![preview](material/screenshot/gotz-15-2.png)
 
+Show arbitrary time using different timezone (explicit TZ code):
+
+```bash
+gotz 15@Asia/Tokyo
+```
+
+![preview](material/screenshot/gotz-15-3.png)
+
 Time can be one of the following formats:
 
 ```txt

core/args.go

@@ -202,7 +202,7 @@ func ParseFlags(startConfig Config, appVersion string) (Config, time.Time, bool,
 	// Handle direct flags
 	if requestTime != "" {
 		// Parse time
-		rTime, err := parseRequestTime(startConfig, requestTime)
+		rTime, err := ParseRequestTime(startConfig, requestTime)
 		if err != nil {
 			return startConfig, rt, changed, err
 		}
@@ -216,7 +216,7 @@ func ParseFlags(startConfig Config, appVersion string) (Config, time.Time, bool,
 		// If last argument is a time, parse it
 		if len(lastArg) > 0 && lastArg[0] >= '0' && lastArg[0] <= '9' {
 			// Parse time
-			rTime, err := parseRequestTime(startConfig, lastArg)
+			rTime, err := ParseRequestTime(startConfig, lastArg)
 			if err != nil {
 				return startConfig, rt, changed, err
 			}
@@ -279,36 +279,46 @@ type inputTimeFormat struct {
 	TZInfo bool
 }
 
-// parseRequestTime parses a requested time in various formats. Furthermore, it
+// ParseRequestTime parses a requested time in various formats. Furthermore, it
 // reads an optional timezone index and uses its timezone instead of local.
-func parseRequestTime(config Config, t string) (time.Time, error) {
+func ParseRequestTime(config Config, t string) (time.Time, error) {
 	tzSeparator := "@"
 	tz := time.Local
 	// Check whether a different time zone than the local one was specified.
 	if strings.Contains(t, tzSeparator) {
 		// Split time and timezone
 		parts := strings.Split(t, tzSeparator)
 		if len(parts) != 2 {
-			return time.Time{}, fmt.Errorf("invalid time format: %s (should be <timezone-index>/<time>)", t)
+			return time.Time{}, fmt.Errorf("invalid time format: %s (should be <time>@<timezone-index> or <time>@<timezone-identifier>)", t)
 		}
-		// Parse timezone index
-		tzIndex, err := strconv.Atoi(parts[1])
-		if err != nil {
-			return time.Time{}, fmt.Errorf("invalid time format: %s (should be <timezone-index>/<time>)", t)
-		}
-		if tzIndex < 0 || tzIndex > len(config.Timezones) {
-			return time.Time{}, fmt.Errorf("invalid time format: %s (timezone-index out of range)", t)
-		}
-		t = parts[0]
-		// Get timezone at index (offset by one to account for 0 as local timezone)
-		if tzIndex > 0 {
-			tz, err = time.LoadLocation(config.Timezones[tzIndex-1].TZ)
+		if checkTimezoneLocation(parts[1]) {
+			// >>> Handle the explicitly given timezone
+			explicitTZ, err := time.LoadLocation(parts[1])
+			if err == nil {
+				// Use explicit timezone
+				tz = explicitTZ
+			}
+		} else {
+			// >>> Handle the timezone index referring to the configured TZs
+			tzIndex, err := strconv.Atoi(parts[1])
 			if err != nil {
-				return time.Time{}, fmt.Errorf("invalid timezone: %s (given index %d)",
-					config.Timezones[tzIndex-1].TZ,
-					tzIndex)
+				return time.Time{}, fmt.Errorf("invalid time format: %s (should be <time>@<timezone-index> or <time>@<timezone-identifier>)", t)
+			}
+			if tzIndex < 0 || tzIndex > len(config.Timezones) {
+				return time.Time{}, fmt.Errorf("invalid time format: %s (timezone-index out of range)", t)
+			}
+			// Get timezone at index (offset by one to account for 0 as local timezone)
+			if tzIndex > 0 {
+				tz, err = time.LoadLocation(config.Timezones[tzIndex-1].TZ)
+				if err != nil {
+					return time.Time{}, fmt.Errorf("invalid timezone: %s (given index %d)",
+						config.Timezones[tzIndex-1].TZ,
+						tzIndex)
+				}
 			}
 		}
+		// Keep time element
+		t = parts[0]
 	}
 	// Parse time
 	rt, err := parseTime(t, tz)

material/screenshot/gotz-15-1.png

@@ -0,0 +1,55 @@
+package core_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/merschformann/gotz/core"
+)
+
+func TestParseRequest(t *testing.T) {
+	defaultConfig := core.DefaultConfig()
+	londonTZ, _ := time.LoadLocation("Europe/London")
+	berlinTZ, _ := time.LoadLocation("Europe/Berlin")
+	// Define test cases
+	tests := []struct {
+		name     string
+		input    string
+		expected time.Time
+	}{
+		{
+			name:     "London",
+			input:    "1100@Europe/London",
+			expected: time.Date(2023, 10, 1, 11, 0, 0, 0, londonTZ),
+		},
+		{
+			name:     "Berlin",
+			input:    "7pm@Europe/Berlin",
+			expected: time.Date(2023, 10, 1, 19, 0, 0, 0, berlinTZ),
+		},
+		{
+			name:     "BerlinIndexed",
+			input:    "7pm@2",
+			expected: time.Date(2023, 10, 1, 19, 0, 0, 0, berlinTZ),
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			// Parse the request
+			parsedTime, err := core.ParseRequestTime(defaultConfig, test.input)
+			if err != nil {
+				t.Fatalf("Error parsing request: %v", err)
+			}
+			// Check if the parsed time matches the expected time (ignore the
+			// date)
+			if parsedTime.Hour() != test.expected.Hour() || parsedTime.Minute() != test.expected.Minute() {
+				t.Errorf("Expected %v, got %v", test.expected, parsedTime)
+			}
+			// Check if the timezone matches the expected timezone
+			if parsedTime.Location().String() != test.expected.Location().String() {
+				t.Errorf("Expected timezone %v, got %v", test.expected.Location(), parsedTime.Location())
+			}
+		})
+	}
+}