Merge pull request 'Add vieter schedule command' (#201) from Chewing_Bever/vieter:schedule-cli into dev

Reviewed-on: vieter/vieter#201

src/console/schedule/schedule.v

@@ -0,0 +1,30 @@
+module schedule
+
+import cli
+import cron.expression { parse_expression }
+import time
+
+// cmd returns the cli submodule for previewing a cron schedule.
+pub fn cmd() cli.Command {
+	return cli.Command{
+		name: 'schedule'
+		usage: 'schedule'
+		description: 'Preview the behavior of a cron schedule.'
+		flags: [
+			cli.Flag{
+				name: 'count'
+				description: 'How many scheduled times to show.'
+				flag: cli.FlagType.int
+				default_value: ['5']
+			},
+		]
+		execute: fn (cmd cli.Command) ? {
+			ce := parse_expression(cmd.args.join(' '))?
+			count := cmd.flags.get_int('count')?
+
+			for t in ce.next_n(time.now(), count)? {
+				println(t)
+			}
+		}
+	}
+}

src/cron/expression/expression.v

@@ -121,6 +121,20 @@ pub fn (ce &CronExpression) next_from_now() ?time.Time {
 	return ce.next(time.now())
 }
 
+// next_n returns the n next occurences of the expression, given a starting
+// time.
+pub fn (ce &CronExpression) next_n(ref time.Time, n int) ?[]time.Time {
+	mut times := []time.Time{cap: n}
+
+	times << ce.next(ref)?
+
+	for i in 1 .. n {
+		times << ce.next(times[i - 1])?
+	}
+
+	return times
+}
+
 // parse_range parses a given string into a range of sorted integers, if
 // possible.
 fn parse_range(s string, min int, max int, mut bitv []bool) ? {

src/main.v

@@ -5,6 +5,7 @@ import server
 import cli
 import console.git
 import console.logs
+import console.schedule
 import cron
 
 fn main() {
@@ -27,6 +28,7 @@ fn main() {
 			git.cmd(),
 			cron.cmd(),
 			logs.cmd(),
+			schedule.cmd(),
 		]
 	}
 	app.setup()