Make arc tasks print output in a unicode-aware and console-width-aware way

Summary:
Currently, we print `arc tasks` in a console-agnostic and unicode-unaware way, so:

  - Tasks with multibyte characters get aligned incorrectly (see T1831); and
  - narrow terminals plus long task names results in a broken display.

Test Plan: Ran `arc tasks`. Will post screenshots.

Reviewers: btrahan, vrana, Korvin

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T749, T1831

Differential Revision: https://secure.phabricator.com/D3568

src/workflow/ArcanistTasksWorkflow.php

@@ -87,14 +87,33 @@ EOTEXT
     $order = $this->getArgument('order');
     $limit = $this->getArgument('limit');
     $this->tasks = $this->loadManiphestTasks(
-      ($status == 'all'?'any':$status),
-      ($owner?$this->findOwnerPhid($owner):$this->getUserPHID()),
+      ($status == 'all' ? 'any' : $status),
+      ($owner ? $this->findOwnerPhid($owner) : $this->getUserPHID()),
       $order,
-      $limit
+      $limit);
+
+    $task_rows = array();
+    foreach ($this->tasks as $task) {
+      $output = array();
+
+      // Render the "T123" column.
+      $task_id = "T".$task['id'];
+      $formatted_task_id = phutil_console_format(
+        '**%s**',
+        $task_id);
+      $output['id'] = array(
+        'text' => $formatted_task_id,
+        'len'  => phutil_utf8_console_strlen($task_id),
       );
 
-    foreach ($this->tasks as $task) {
-      $tid = "T{$task['id']}";
+      // Render the "Title" column.
+      $formatted_title = rtrim($task['title']);
+      $output['title'] = array(
+        'text' => $formatted_title,
+        'len'  => phutil_utf8_console_strlen($formatted_title),
+      );
+
+      // Render the "Priority" column.
       switch ($task['priority']) {
         case 'Needs Triage':
           $color = 'magenta';
@@ -118,35 +137,83 @@ EOTEXT
           $color = 'white';
         break;
       }
-      $task_priority = $task['priority'];
-      $priority = phutil_console_format("<bg:{$color}> </bg>{$task_priority}");
-      $output[] = array(phutil_console_format("**{$tid}**"),
-                        $task['title'],
-                        $priority,
-                        ($task['status']?
-                          phutil_console_format("<bg:red> </bg>Closed"):
-                          phutil_console_format('<bg:green> </bg>Open'))
-                );
-    }
-    $this->render($output);
-  }
+      $formatted_priority = phutil_console_format(
+        "<bg:{$color}> </bg> %s",
+        $task['priority']);
+      $output['priority'] = array(
+        'text'  => $formatted_priority,
+        'len'   => phutil_utf8_console_strlen($task['priority']) + 2,
+      );
 
-  private function render($table) {
-    $column_length = array();
-    foreach ($table as $row) {
-      foreach ($row as $col => $cell) {
-        if (!isset($column_length[$col]))
-          $column_length[$col] = 0;
-        if (strlen($cell) > $column_length[$col])
-          $column_length[$col] = strlen($cell);
+      // Render the "Status" column.
+      if ($task['status']) {
+        $status_text = 'Closed';
+        $status_color = 'red';
+      } else {
+        $status_text = 'Open';
+        $status_color = 'green';
+      }
+      $formatted_status = phutil_console_format(
+        "<bg:{$status_color}> </bg> %s",
+        $status_text);
+      $output['status'] = array(
+        'text'  => $formatted_status,
+        'len'   => phutil_utf8_console_strlen('status') + 2,
+      );
+
+      $task_rows[] = $output;
+    }
+
+    // Find the longest string in each column.
+    $col_size = array();
+    foreach ($task_rows as $row) {
+      foreach ($row as $key => $col) {
+        if (empty($col_size[$key])) {
+          $col_size[$key] = 0;
+        }
+        $col_size[$key] = max($col_size[$key], $col['len']);
       }
     }
-    foreach ($table as $row) {
-      foreach ($row as $col => $cell) {
-        echo $cell.str_repeat(' ', $column_length[$col] - strlen($cell) + 4);
-      }
-      echo "\n";
+
+    // Determine the terminal width. If we can't figure it out, assume 80.
+    $width = nonempty(phutil_console_get_terminal_width(), 80);
+
+
+    // We're going to clip the titles so they'll all fit in one line on the
+    // terminal. Figure out where to clip them.
+    $padding_between_columns = 4;
+    $clip_title_at = max(
+      // Always show at least a little bit of text even if it will make the
+      // UI wrap, since it's useless if we don't show anything.
+      16,
+      $width -
+        ($col_size['id'] + $col_size['priority'] + $col_size['status'] +
+        ($padding_between_columns * 3)));
+    $col_size['title'] = min($col_size['title'], $clip_title_at);
+
+    foreach ($task_rows as $key => $cols) {
+      $new_title = phutil_utf8_shorten($cols['title']['text'], $clip_title_at);
+
+      $task_rows[$key]['title']['len'] = phutil_utf8_console_strlen($new_title);
+      $task_rows[$key]['title']['text'] = $new_title;
     }
+
+    $table = array();
+    foreach ($task_rows as $row) {
+      $trow = array();
+      foreach ($row as $col => $cell) {
+        $text = $cell['text'];
+        $pad_len = $col_size[$col] - $cell['len'];
+        if ($pad_len) {
+          $text .= str_repeat(' ', $pad_len);
+        }
+        $trow[] = $text;
+      }
+      $table[] = implode(str_repeat(' ', $padding_between_columns), $trow);
+    }
+    $table = implode("\n", $table)."\n";
+
+    echo $table;
   }
 
   private function findOwnerPhid($owner) {