From 798bbeb9bb84a81f8f07f944e2e28002b80305ca Mon Sep 17 00:00:00 2001
From: Dan Peterson <danp@danp.net>
Date: Sun, 14 Mar 2021 15:48:26 -0300
Subject: [PATCH] driver: support scanning more formats into time.Time

Fixes https://gitlab.com/cznic/sqlite/-/issues/46
---
 all_test.go | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 sqlite.go   | 23 ++++++++++++++++++++++-
 2 files changed, 73 insertions(+), 1 deletion(-)

diff --git a/all_test.go b/all_test.go
index e631e11..fd8d4a2 100644
--- a/all_test.go
+++ b/all_test.go
@@ -1127,6 +1127,57 @@ func TestTime(t *testing.T) {
 	}
 }
 
+// https://gitlab.com/cznic/sqlite/-/issues/46
+func TestTimeScan(t *testing.T) {
+	ref := time.Date(2021, 1, 2, 16, 39, 17, 123456789, time.UTC)
+
+	cases := []struct {
+		s string
+		w time.Time
+	}{
+		{s: "2021-01-02 12:39:17 -0400 ADT m=+00000", w: ref.Truncate(time.Second)},
+		{s: "2021-01-02 16:39:17 +0000 UTC m=+0.000000001", w: ref.Truncate(time.Second)},
+		{s: "2021-01-02 12:39:17.123456 -0400 ADT m=+00000", w: ref.Truncate(time.Microsecond)},
+		{s: "2021-01-02 16:39:17.123456 +0000 UTC m=+0.000000001", w: ref.Truncate(time.Microsecond)},
+		{s: "2021-01-02 16:39:17Z", w: ref.Truncate(time.Second)},
+		{s: "2021-01-02 16:39:17+00:00", w: ref.Truncate(time.Second)},
+		{s: "2021-01-02T16:39:17.123456+00:00", w: ref.Truncate(time.Microsecond)},
+		{s: "2021-01-02 16:39:17.123456+00:00", w: ref.Truncate(time.Microsecond)},
+		{s: "2021-01-02 12:39:17-04:00", w: ref.Truncate(time.Second)},
+		{s: "2021-01-02 16:39:17", w: ref.Truncate(time.Second)},
+		{s: "2021-01-02T16:39:17", w: ref.Truncate(time.Second)},
+		{s: "2021-01-02 16:39", w: ref.Truncate(time.Minute)},
+		{s: "2021-01-02T16:39", w: ref.Truncate(time.Minute)},
+		{s: "2021-01-02", w: ref.Truncate(24 * time.Hour)},
+	}
+
+	db, err := sql.Open(driverName, "file::memory:")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer db.Close()
+
+	for _, colType := range []string{"DATE", "DATETIME", "TIMESTAMP"} {
+		for _, tc := range cases {
+			if _, err := db.Exec("drop table if exists x; create table x (y " + colType + ")"); err != nil {
+				t.Fatal(err)
+			}
+			if _, err := db.Exec("insert into x (y) values (?)", tc.s); err != nil {
+				t.Fatal(err)
+			}
+
+			var got time.Time
+
+			if err := db.QueryRow("select y from x").Scan(&got); err != nil {
+				t.Fatal(err)
+			}
+			if !got.Equal(tc.w) {
+				t.Errorf("scan(%q as %q) = %s, want %s", tc.s, colType, got, tc.w)
+			}
+		}
+	}
+}
+
 // https://sqlite.org/lang_expr.html#varparam
 // https://gitlab.com/cznic/sqlite/-/issues/42
 func TestBinding(t *testing.T) {
diff --git a/sqlite.go b/sqlite.go
index 0b6e054..11bfde3 100644
--- a/sqlite.go
+++ b/sqlite.go
@@ -304,6 +304,19 @@ func (r *rows) Next(dest []driver.Value) (err error) {
 	}
 }
 
+// Inspired by mattn/go-sqlite3: https://github.com/mattn/go-sqlite3/blob/ab91e934/sqlite3.go#L210-L226
+//
+// These time.Parse formats handle formats 1 through 7 listed at https://www.sqlite.org/lang_datefunc.html.
+var parseTimeFormats = []string{
+	"2006-01-02 15:04:05.999999999-07:00",
+	"2006-01-02T15:04:05.999999999-07:00",
+	"2006-01-02 15:04:05.999999999",
+	"2006-01-02T15:04:05.999999999",
+	"2006-01-02 15:04",
+	"2006-01-02T15:04",
+	"2006-01-02",
+}
+
 // Attempt to parse s as a time. Return (s, false) if s is not
 // recognized as a valid time encoding.
 func (c *conn) parseTime(s string) (interface{}, bool) {
@@ -311,7 +324,15 @@ func (c *conn) parseTime(s string) (interface{}, bool) {
 		return v, true
 	}
 
-	// TODO Add URI select time storage format and handle more formats
+	ts := strings.TrimSuffix(s, "Z")
+
+	for _, f := range parseTimeFormats {
+		t, err := time.Parse(f, ts)
+		if err == nil {
+			return t, true
+		}
+	}
+
 	return s, false
 }