From 1be64beb0eaec6f8d7ae531e00c3fe8d47bce0b6 Mon Sep 17 00:00:00 2001
From: Bill Chen <Bill.Chen@live.com>
Date: Fri, 13 Aug 2021 21:38:49 +0800
Subject: [PATCH] feat: Select problem of today.

Change-Id: Id51718d1abeb0564c3e70c94e5698d79dc174f19
---
 lib/commands/show.js       | 16 ++++++++++++++++
 lib/core.js                | 15 +++++++++++++++
 lib/plugins/leetcode.cn.js | 28 ++++++++++++++++++++++++++++
 lib/plugins/leetcode.js    | 26 ++++++++++++++++++++++++++
 test/test_core.js          | 10 ++++++++++
 5 files changed, 95 insertions(+)

diff --git a/lib/commands/show.js b/lib/commands/show.js
index 93f643e..b71c53a 100644
--- a/lib/commands/show.js
+++ b/lib/commands/show.js
@@ -63,6 +63,12 @@ const cmd = {
         default:  false,
         describe: 'Set to true to disable endpoint\'s translation',
       })
+      .option('d', {
+        alias:    'daily',
+        type:     'boolean',
+        default:  false,
+        describe: 'Show question of the day.'
+      })
       .positional('keyword', {
         type:     'string',
         default:  '',
@@ -179,6 +185,16 @@ function showProblem(problem, argv) {
 
 cmd.handler = function(argv) {
   session.argv = argv;
+
+  if (argv.daily) {
+    // Show problem of the day.
+    core.getProblemOfToday(!argv.dontTranslate, function(e, problem) {
+      if (e) return log.fail(e);
+      showProblem(problem, argv);
+    })
+    return;
+  }
+
   if (argv.keyword.length > 0) {
     // show specific one
     core.getProblem(argv.keyword, !argv.dontTranslate, function(e, problem) {
diff --git a/lib/core.js b/lib/core.js
index c9df632..38352a6 100644
--- a/lib/core.js
+++ b/lib/core.js
@@ -99,6 +99,21 @@ core.getProblem = function(keyword, needTranslation, cb) {
   });
 };
 
+core.getProblemOfToday = function(needTranslation, cb) {
+  core.next.getProblemOfToday(needTranslation, function (e, problemSlug) {
+    if (e) return cb(e);
+    
+    core.getProblems(needTranslation, function(e, problems) {
+      if (e) return cb(e);
+      const problem = problems.find(function(x) {
+        return x.slug === problemSlug;
+      })
+      if (!problem) return cb('Problem not found!');
+      core.next.getProblem(problem, needTranslation, cb);
+    });
+  });
+}
+
 core.starProblem = function(problem, starred, cb) {
   if (problem.starred === starred) {
     log.debug('problem is already ' + (starred ? 'starred' : 'unstarred'));
diff --git a/lib/plugins/leetcode.cn.js b/lib/plugins/leetcode.cn.js
index 77639c7..ecc98a7 100644
--- a/lib/plugins/leetcode.cn.js
+++ b/lib/plugins/leetcode.cn.js
@@ -70,6 +70,34 @@ function checkError(e, resp, expectedStatus) {
   return e;
 }
 
+
+// Daily Challenge for leetcode-cn.com
+plugin.getProblemOfToday = function (needTranslation, cb) {
+  log.debug('running leetcode.getProblemOfToday...');
+  const opts = plugin.makeOpts(config.sys.urls.graphql);
+  opts.headers.Origin = config.sys.urls.base;
+  opts.headers.Referer = config.sys.urls.base;
+
+  opts.json = true;
+  opts.body = {
+    query:         'query questionOfToday { todayRecord { question { questionId questionTitleSlug }}}',
+    variables:     {},
+    operationName: 'questionOfToday'
+  };
+
+  const spin = h.spin('Getting problem of today...');
+  request.post(opts, function (e, resp, body) {
+    spin.stop();
+    e = plugin.checkError(e, resp, 200);
+    if (e) return cb(e);
+
+    const slug = body.data.todayRecord[0].question.questionTitleSlug;
+    log.debug('Daily problem:', slug);
+    return cb(null, slug);
+  });
+}
+
+
 // overloading getProblems here to make sure everything related 
 //   to listing out problems can have a chance to be translated. 
 // NOTE: Details of the problem is translated inside leetcode.js
diff --git a/lib/plugins/leetcode.js b/lib/plugins/leetcode.js
index 9e81014..ebefafe 100644
--- a/lib/plugins/leetcode.js
+++ b/lib/plugins/leetcode.js
@@ -77,6 +77,32 @@ plugin.getProblems = function (needTranslation, cb) {
   });
 };
 
+// Daily challenge for leetcode.com
+plugin.getProblemOfToday = function(needTranslation, cb) {
+  log.debug('running leetcode.getProblemOfToday...');
+  const opts = plugin.makeOpts(config.sys.urls.graphql);
+  opts.headers.Origin = config.sys.urls.base;
+  opts.headers.Referer = config.sys.urls.base;
+
+  opts.json = true;
+  opts.body = {
+    query:         'query questionOfToday { currentDailyCodingChallenge { questionOfToday { question { titleSlug } } } }',
+    variables:     {},
+    operationName: 'questionOfToday'
+  };
+
+  const spin = h.spin('Getting problem of today...');
+  request.post(opts, function (e, resp, body) {
+    spin.stop();
+    e = plugin.checkError(e, resp, 200);
+    if (e) return cb(e);
+
+    const slug = body.data.currentDailyCodingChallenge.questionOfToday.question.titleSlug;
+    log.debug('Daily problem:', slug);
+    return cb(null, slug);
+  });
+}
+
 plugin.getCategoryProblems = function(category, cb) {
   log.debug('running leetcode.getCategoryProblems: ' + category);
   const opts = plugin.makeOpts(config.sys.urls.problems.replace('$category', category));
diff --git a/test/test_core.js b/test/test_core.js
index 1c689f5..58c31a6 100644
--- a/test/test_core.js
+++ b/test/test_core.js
@@ -389,5 +389,15 @@ describe('core', function() {
         done();
       });
     });
+
+    it('should get problem of today ok', function(done) {
+      next.getProblemOfToday = (needT, cb) => {
+        cb(null, 'slug0');
+      }
+      core.getProblemOfToday(false, function(e, problem) {
+        assert.notExists(e);
+        done();
+      })
+    })
   }); // #getProblem
 });