From c52bd93256a4124e7399204ff67a9c0145d5f578 Mon Sep 17 00:00:00 2001
From: Jonathan Delgado <hi@jon.soy>
Date: Wed, 12 Oct 2022 02:31:31 -0300
Subject: [PATCH] feat: initial commit

---
 README.md |  23 +++++++++++
 ndate.ts  | 116 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 139 insertions(+)
 create mode 100644 README.md
 create mode 100644 ndate.ts

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..15b20db
--- /dev/null
+++ b/README.md
@@ -0,0 +1,23 @@
+# ndate script
+
+Date format to console.
+
+```shell
+Usage: ndate [-] [--zero] [--date-style <full|long|medium|short>] [--time-style <full|long|medium|short>]
+             [--local <locale>] [--json] [--date <date>] [--help] [-j] [-d <date>]
+             [-l <locale>] [-z] [-h]
+```
+
+Please install with deno:
+
+```shell
+deno install ndate.ts
+```
+
+Samples use:
+
+```shell
+ndate # Tuesday, October 11, 2022 at 5:59:37 PM Chile Summer Time
+ndate --local es-CL # martes, 11 de octubre de 2022, 17:59:14 hora de verano de Chile
+ndate --local en-CL # Tuesday, October 11, 2022 at 5:59:37 PM Chile Summer Time
+```
diff --git a/ndate.ts b/ndate.ts
new file mode 100644
index 0000000..981830d
--- /dev/null
+++ b/ndate.ts
@@ -0,0 +1,116 @@
+const dateStyles = ["full", "long", "medium", "short"] as const;
+const timeStyles = ["full", "long", "medium", "short"] as const;
+type DateStyle = (typeof dateStyles)[number];
+type TimeStyle = (typeof dateStyles)[number];
+const toDateStyle = (v: unknown): DateStyle | undefined => typeof v === "string" ? dateStyles.find(dateStyle => dateStyle.startsWith(v)) : undefined;
+const toTimeStyle = (v: unknown): DateStyle | undefined => typeof v === "string" ? timeStyles.find(timeStyle => timeStyle.startsWith(v)) : undefined;
+const dateParse = (val: string): Date => {
+    const d = new Date(val);
+    if (Number.isNaN(Number(d))) {
+        throw new Error(`the ${Deno.inspect(val)} time stamp no valid`);
+    }
+    return d;
+}
+
+let dateStyle: DateStyle = 'full';
+let timeStyle: TimeStyle = 'full';
+let newLine = true;
+let local: string | undefined;
+let date = new Date();
+let json = false;
+let stdinRedeable = false;
+let showHelp = false;
+
+const transformOptions: Record<string, (next: () => string | undefined) => void> = {
+    '-': () => { stdinRedeable = true },
+    '--zero': () => { newLine = false; },
+    '--date-style': (next) => { dateStyle = toDateStyle(next()) ?? 'full' },
+    '--time-style': (next) => { timeStyle = toTimeStyle(next()) ?? 'full' },
+    '--local': (next) => { local = next() },
+    '--json': () => { json = true },
+    '--date': (next) => {
+        const v = next();
+        if (v) {
+            date = dateParse(v);
+        }
+    },
+    '--help': () => { showHelp = true },
+    get "-j"() { return this['--json'] },
+    get "-d"() { return this["--date"] },
+    get "-l"() { return this["--local"] },
+    get "-z"() { return this["--zero"] },
+    get "-h"() { return this["--help"] },
+};
+
+const optionsLabels: Record<string, undefined | { label?: string }> = {
+    '--date-style': { label: `<${dateStyles.join('|')}>` },
+    '--time-style': { label: `<${timeStyles.join('|')}>` },
+    '--local': { label: `<locale>` },
+    '--date': { label: `<date>` },
+    get "-j"() { return this['--json'] },
+    get "-d"() { return this["--date"] },
+    get "-l"() { return this["--local"] },
+    get "-z"() { return this["--zero"] },
+    get "-h"() { return this["--help"] },
+};
+
+for (
+    let argsCursor = Deno.args[Symbol.iterator](),
+    { value: arg, done } = argsCursor.next();
+    !done;
+    { value: arg, done } = argsCursor.next()
+) {
+    const next = (): string | undefined => argsCursor.next().value;
+    if (typeof arg === "string" && arg in transformOptions) { transformOptions[arg](next); }
+}
+
+const run = async () => {
+    if (showHelp) {
+        const items = Object.keys(transformOptions)
+            .map(item => {
+                const label = optionsLabels[item]?.label;
+                return label ? `[${item} ${label}]` : `[${item}]`;
+            });
+
+        const textUsage = `Usage: ndate`;
+
+        const lines: string[] = [];
+        let currentLine: string | undefined;
+        for (const item of items) {
+            if (!currentLine) {
+                currentLine = lines.length ? `${' '.repeat(textUsage.length)}` : `${textUsage}`;
+            }
+
+            currentLine = `${currentLine} ${item}`;
+            if (currentLine.length > 80) {
+                lines.push(currentLine);
+                currentLine = undefined;
+            }
+        }
+
+        if (currentLine) lines.push(currentLine);
+
+        for (const line of lines) {
+            console.log(line);
+        }
+
+        return;
+    }
+
+    if (stdinRedeable) {
+        const buff = new Uint8Array(256);
+        await Deno.stdin.read(buff);
+        const text = new TextDecoder().decode(buff.subarray(0, buff.findIndex(p => p === 0))).trim();
+        date = dateParse(text);
+    }
+
+    const dateStr = json ? date.toJSON() : date.toLocaleString(local, { dateStyle, timeStyle });
+
+    Deno.stdout.write(new TextEncoder().encode(dateStr))
+
+    if (newLine) Deno.stdout.write(
+        new TextEncoder().encode(`\n`)
+    )
+}
+
+await run();