From 6d60ea15380bdaede26216918e0922edd701f1b5 Mon Sep 17 00:00:00 2001
From: Jef Roosens <roosensjef@gmail.com>
Date: Sun, 10 Apr 2022 16:17:50 +0200
Subject: [PATCH] Started writing cron expression parser [CI SKIP]

---
 Makefile                   |  4 +++
 src/cron/cron.v            | 27 ++++++++++++++++++-
 src/cron/expression.v      | 55 ++++++++++++++++++++++++++++++++++++++
 src/cron/expression_test.v |  5 ++++
 src/util.v                 |  1 +
 5 files changed, 91 insertions(+), 1 deletion(-)
 create mode 100644 src/cron/expression.v
 create mode 100644 src/cron/expression_test.v

diff --git a/Makefile b/Makefile
index 76ab7b58..9421fb6f 100644
--- a/Makefile
+++ b/Makefile
@@ -60,6 +60,10 @@ fmt:
 vet:
 	$(V) vet -W $(SRC_DIR)
 
+.PHONY: test
+test:
+	$(V) test $(SRC_DIR)
+
 # Build & patch the V compiler
 .PHONY: v
 v: v/v
diff --git a/src/cron/cron.v b/src/cron/cron.v
index ac584eb9..ccb8f9e6 100644
--- a/src/cron/cron.v
+++ b/src/cron/cron.v
@@ -1,7 +1,32 @@
 module cron
 
 import git
+import datatypes
+import time
+
+struct ScheduledBuild {
+	repo git.GitRepo
+	timestamp time.Time
+}
+
+fn (r1 ScheduledBuild) < (r2 ScheduledBuild) bool {
+	return r1.timestamp < r2.timestamp
+}
 
 pub fn cron(conf Config) ? {
-	repos_map := git.get_repos(conf.address, conf.api_key) ?
+	// mut queue := datatypes.MinHeap<ScheduledBuild>{}
+	// repos_map := git.get_repos(conf.address, conf.api_key) ?
+
+	// for _, repo in repos_map {
+	// 	scheduled := ScheduledBuild{
+	// 		repo: repo
+	// 		timestamp: 25
+	// 	}
+
+	// 	queue.insert(scheduled)
+	// }
+
+	// println(queue)
+	exp := "10/2 5 *"
+	println(parse_expression(exp) ?)
 }
diff --git a/src/cron/expression.v b/src/cron/expression.v
new file mode 100644
index 00000000..8dae499e
--- /dev/null
+++ b/src/cron/expression.v
@@ -0,0 +1,55 @@
+module cron
+
+import math
+
+struct CronExpression {
+	minutes []u32
+	hours []u32
+	days []u32
+}
+
+// parse_range parses a given string into a range of integers, if possible.
+fn parse_range(s string, min u32, max u32) ?[]u32 {
+	mut out := []u32{}
+	mut start := min
+	mut interval := u32(1)
+
+	if s != '*' {
+		exps := s.split('/')
+
+		if exps.len > 1 {
+			interval = exps[1].u32()
+		}
+		// Here, s solely consists of a number, so that's the only value we
+		// should return.
+		else{
+			return [exps[0].u32()]
+		}
+
+		if exps[0] != '*' {
+			start = math.max(exps[0].u32(), min)
+		}
+	}
+
+	for start <= max {
+		out << start
+		start += interval
+	}
+
+	return out
+}
+
+// min hour day month day-of-week
+fn parse_expression(exp string) ?CronExpression {
+	parts := exp.split(' ')
+
+	if parts.len != 3 {
+		return error("Expression must contain 5 space-separated parts.")
+	}
+
+	return CronExpression{
+		minutes: parse_range(parts[0], 0, 59) ?
+		hours: parse_range(parts[1], 0, 23) ?
+		days: parse_range(parts[2], 0, 31) ?
+	}
+}
diff --git a/src/cron/expression_test.v b/src/cron/expression_test.v
new file mode 100644
index 00000000..b3b7422a
--- /dev/null
+++ b/src/cron/expression_test.v
@@ -0,0 +1,5 @@
+module cron
+
+fn test_parse_star_range() {
+	assert parse_range('*', 0, 5) == [0, 1, 2, 3, 4, 5]
+}
diff --git a/src/util.v b/src/util.v
index 49c9d223..228f5845 100644
--- a/src/util.v
+++ b/src/util.v
@@ -44,6 +44,7 @@ pub fn reader_to_file(mut reader io.BufferedReader, length int, path string) ? {
 		for to_write > 0 {
 			// TODO don't just loop infinitely here
 			bytes_written := file.write(buf[bytes_read - to_write..bytes_read]) or { continue }
+			// file.flush()
 
 			to_write = to_write - bytes_written
 		}