From 085fcdb63efbb80dcf619e020f41a4f0a1ccecbb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20P=C4=99dzich?= <contact@maciejpedzi.ch>
Date: Thu, 8 Jun 2023 18:58:14 +0200
Subject: [PATCH] Create and use the useVote composable

---
 src/composables/useVote.ts | 122 +++++++++++++++++++++++++++++++++++++
 src/views/Vote.vue         |  27 +++-----
 2 files changed, 130 insertions(+), 19 deletions(-)
 create mode 100644 src/composables/useVote.ts

diff --git a/src/composables/useVote.ts b/src/composables/useVote.ts
new file mode 100644
index 0000000..f95f8ef
--- /dev/null
+++ b/src/composables/useVote.ts
@@ -0,0 +1,122 @@
+import { computed, reactive, ref, toRefs } from 'vue';
+import glicko2 from 'glicko2-lite';
+
+import photos from '@/photos.json';
+import { Database, Photo } from '@/models';
+import { randomNumber } from '@/utils/randomNumber';
+
+const db = reactive<Database>(
+  JSON.parse(localStorage.getItem('db') as string) || {
+    photos,
+    votes: []
+  }
+);
+
+const photosInCurrentVote = ref<Photo[]>([]);
+
+const photosForFirstPick = computed(() =>
+  db.photos.filter(({ fileName }) => {
+    const appearanceCount = db.votes.filter((vote) =>
+      vote.photos.includes(fileName)
+    ).length;
+
+    return appearanceCount !== db.photos.length - 1;
+  })
+);
+
+export function useVote() {
+  const pickPhotosForNewVote = () => {
+    const firstPick =
+      photosForFirstPick.value[
+        randomNumber(0, photosForFirstPick.value.length - 1)
+      ];
+
+    const photosForSecondPick = db.photos.filter(({ fileName }) => {
+      const votesWithFirstPick = db.votes.filter(({ photos }) =>
+        photos.includes(firstPick.fileName)
+      );
+
+      const fileNamesToExclude = [
+        ...new Set(votesWithFirstPick.flatMap(({ photos }) => photos))
+      ];
+
+      return !fileNamesToExclude.includes(fileName);
+    });
+
+    const secondPick =
+      photosForSecondPick[randomNumber(0, photosForSecondPick.length - 1)];
+
+    photosInCurrentVote.value.push(firstPick, secondPick);
+  };
+
+  const submitVote = (result: 0 | 0.5 | 1) => {
+    const fileNames = [...photosInCurrentVote.value].map(
+      ({ fileName }) => fileName
+    ) as [string, string];
+
+    db.votes.unshift({ photos: fileNames, result });
+    photosInCurrentVote.value = [];
+    pickPhotosForNewVote();
+  };
+
+  const updateRatings = () => {
+    const twelveMostRecentVotes = db.votes.slice(0, 12).reverse();
+
+    const votesGrouppedByPhotos = twelveMostRecentVotes.reduce((obj, vote) => {
+      const [firstPick, secondPick] = vote.photos;
+
+      const firstPhoto = db.photos.find(
+        ({ fileName }) => fileName === firstPick
+      )!;
+      const secondPhoto = db.photos.find(
+        ({ fileName }) => fileName === secondPick
+      )!;
+
+      const firstPhotoOpponentParams = [
+        secondPhoto.rating,
+        secondPhoto.rd,
+        vote.result
+      ] as [number, number, number];
+
+      const secondPhotoOpponentParams = [
+        firstPhoto.rating,
+        firstPhoto.rd,
+        1 - vote.result
+      ] as [number, number, number];
+
+      if (obj[firstPick]) {
+        obj[firstPick].push(firstPhotoOpponentParams);
+      } else {
+        obj[firstPick] = [firstPhotoOpponentParams];
+      }
+
+      if (obj[secondPick]) {
+        obj[secondPick].push(secondPhotoOpponentParams);
+      } else {
+        obj[secondPick] = [secondPhotoOpponentParams];
+      }
+
+      return obj;
+    }, {} as Record<string, [number, number, number][]>);
+
+    for (const [photoFileName, votes] of Object.entries(
+      votesGrouppedByPhotos
+    )) {
+      const photo = db.photos.find(
+        ({ fileName }) => fileName === photoFileName
+      )!;
+      const newRatingParams = glicko2(photo.rating, photo.rd, photo.vol, votes);
+
+      Object.assign(photo, newRatingParams);
+    }
+  };
+
+  return {
+    photosInCurrentVote,
+    photosForFirstPick,
+    createVote: pickPhotosForNewVote,
+    submitVote,
+    updateRatings,
+    ...toRefs(db)
+  };
+}
diff --git a/src/views/Vote.vue b/src/views/Vote.vue
index 1573177..1eb2588 100644
--- a/src/views/Vote.vue
+++ b/src/views/Vote.vue
@@ -1,18 +1,7 @@
 <script lang="ts" setup>
-import { computed, onMounted, ref } from 'vue';
+import { useVote } from '@/composables/useVote';
 
-import { useSnackbar } from '@/composables/useSnackbar';
-import { useRandomNumber } from '@/composables/useRandomNumber';
-
-import { Vote } from '@/models/vote';
-import { Photo } from '@/models/photo';
-import { PhotoAppearanceCount } from '@/models/photoAppearanceCount';
-
-const { showSnackbar } = useSnackbar();
-const randomNumber = useRandomNumber();
-
-const isLoading = ref(true);
-const photosInCurrentVote = ref<Photo[]>([]);
+const { photosInCurrentVote } = useVote();
 </script>
 
 <template>
@@ -29,22 +18,22 @@ const photosInCurrentVote = ref<Photo[]>([]);
     >
       <div
         v-for="(photo, index) in photosInCurrentVote"
-        :key="photo.$id"
+        :key="photo.fileName"
         class="d-flex flex-column align-center px-5 py-4"
       >
         <v-img
-          :src="photo.url"
+          :src="`/images/${photo.fileName}`"
           :alt="photo.altText"
-          max-width="480"
           :aspect-ratio="16 / 9"
+          max-width="480"
         />
         <p class="mt-2 text-h6">Photo {{ index + 1 }}</p>
       </div>
     </div>
     <div id="vote-btns" class="mb-4 d-flex justify-center flex-wrap">
-      <v-btn :disabled="isLoading" size="large">Photo 1</v-btn>
-      <v-btn :disabled="isLoading" size="large">Photo 2</v-btn>
-      <v-btn :disabled="isLoading" size="large">I can't decide</v-btn>
+      <v-btn size="large">Photo 1</v-btn>
+      <v-btn size="large">Photo 2</v-btn>
+      <v-btn size="large">I can't decide</v-btn>
     </div>
   </section>
 </template>