From 22f429e01bc1cfcf63359ec1cb775c3dc07908ec Mon Sep 17 00:00:00 2001
From: Jos de Jong <wjosdejong@gmail.com>
Date: Wed, 2 Sep 2020 20:24:11 +0200
Subject: [PATCH] Implement transform wizard (WIP)

---
 src/components/modals/Modal.scss             |   3 +-
 src/components/modals/TransformModal.scss    |   6 +-
 src/components/modals/TransformModal.svelte  |  13 ++
 src/components/modals/TransformWizard.scss   |  36 +++++
 src/components/modals/TransformWizard.svelte | 133 +++++++++++++++++++
 src/logic/jsCreateQuery.js                   |  47 +++++++
 6 files changed, 235 insertions(+), 3 deletions(-)
 create mode 100644 src/components/modals/TransformWizard.scss
 create mode 100644 src/components/modals/TransformWizard.svelte
 create mode 100644 src/logic/jsCreateQuery.js

diff --git a/src/components/modals/Modal.scss b/src/components/modals/Modal.scss
index f20d71e..5d284ce 100644
--- a/src/components/modals/Modal.scss
+++ b/src/components/modals/Modal.scss
@@ -10,6 +10,7 @@
 
   font-family: $font-family;
   font-size: $font-size;
+  color: $black;
   
   .contents {
     padding: 20px;
@@ -27,5 +28,5 @@
 // custom styling for the modal. 
 // FIXME: not neat to override global styles!
 :global(.bg .window-wrap) {
-  margin-top: 10rem;
+  margin-top: 8rem;
 }
diff --git a/src/components/modals/TransformModal.scss b/src/components/modals/TransformModal.scss
index cc4cf3a..a893221 100644
--- a/src/components/modals/TransformModal.scss
+++ b/src/components/modals/TransformModal.scss
@@ -4,7 +4,7 @@
 .jsoneditor-modal.transform {
 
   .description {
-    padding-bottom: $padding;
+    color: $dark-gray;
 
     code {
       background: $background-gray;
@@ -15,7 +15,8 @@
 
   label {
     font-weight: bold;
-    padding: $padding/2 0;
+    padding-top: $padding * 2;
+    padding-bottom: $padding / 2;
     display: block;
   }
 
@@ -31,6 +32,7 @@
     padding: $padding / 2;
     font-family: $font-family-mono;
     font-size: $font-size-mono;
+    color: $black;
   }
 
   textarea.preview {
diff --git a/src/components/modals/TransformModal.svelte b/src/components/modals/TransformModal.svelte
index 5af48e7..0b9776f 100644
--- a/src/components/modals/TransformModal.svelte
+++ b/src/components/modals/TransformModal.svelte
@@ -8,6 +8,7 @@
   import { transformModalState } from './transformModalState.js'
   import { DEBOUNCE_DELAY, MAX_PREVIEW_CHARACTERS } from '../../constants.js'
   import { truncate } from '../../utils/stringUtils.js'
+  import TransformWizard from './TransformWizard.svelte'
   import * as _ from 'lodash-es'
   import { getIn } from '../../utils/immutabilityHelpers.js'
 
@@ -34,6 +35,11 @@
     return queryFn(json)
   }
 
+  function updateQuery (newQuery) {
+    console.log('updated query by wizard', newQuery)
+    query = newQuery
+  }
+
   function previewTransform(json, query) {
     try {
       const jsonTransformed = evalTransform(json, query)
@@ -96,6 +102,13 @@
       <code>_.pick</code>, <code>_.uniq</code>, <code>_.get</code>, etcetera.
     </div>
 
+    <label>Wizard</label>
+    {#if Array.isArray(json)}
+      <TransformWizard json={json} onQuery={updateQuery} />
+    {:else}
+      (Only available for arrays, not for objects)
+    {/if}
+    
     <label>Query</label>
     <textarea class="query" bind:value={query} />
 
diff --git a/src/components/modals/TransformWizard.scss b/src/components/modals/TransformWizard.scss
new file mode 100644
index 0000000..1c91dea
--- /dev/null
+++ b/src/components/modals/TransformWizard.scss
@@ -0,0 +1,36 @@
+@import '../../styles.scss';
+
+table.transform-wizard {
+  border-collapse: collapse;
+  border-spacing: 0;
+  width: 100%;
+
+  tr {
+    th {
+      font-weight: normal;
+      text-align: left;
+    }
+  
+    td {
+      .horizontal {
+        width: 100%;
+        display: flex;
+        flex-direction: row;
+  
+        .selectContainer.filter-field {
+          flex: 4;
+          margin-right: $padding;
+        }
+        
+        .selectContainer.filter-relation {
+          flex: 1;
+          margin-right: $padding;
+        }
+        
+        .filter-value {
+          flex: 4;
+        }
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/src/components/modals/TransformWizard.svelte b/src/components/modals/TransformWizard.svelte
new file mode 100644
index 0000000..c31274a
--- /dev/null
+++ b/src/components/modals/TransformWizard.svelte
@@ -0,0 +1,133 @@
+<svelte:options immutable={true} />
+
+<script>
+  import Select from 'svelte-select'
+  import { getNestedPaths } from '../../utils/arrayUtils.js'
+  import { stringifyPath } from '../../utils/pathUtils.js'
+  import { createQuery } from '../../logic/jsCreateQuery.js'
+  import { isEqual } from 'lodash-es'
+
+  export let json
+  export let onQuery
+
+  // fields
+  let filterField = undefined
+  let filterRelation = undefined
+  let filterValue = undefined
+  let sortField = undefined
+  let sortDirection = undefined
+  let pickFields = undefined
+
+  // options
+  $: jsonIsArray = Array.isArray(json)
+  $: paths = jsonIsArray ? getNestedPaths(json) : undefined
+  $: fieldOptions = paths ? paths.map(pathToOption) : undefined
+
+  const filterRelationOptions = ['==', '!=', '<', '<=', '>', '>='].map(relation => ({ 
+    value: relation, 
+    label: relation
+  }))
+
+  const sortDirectionOptions = [
+    { value: 'asc', label: 'ascending' },
+    { value: 'desc', label: 'descending' },
+  ]
+
+  function pathToOption (path) {
+    return { 
+        value: path, 
+        label: stringifyPath(path) 
+    }
+  }
+
+  let queryOptions = {}
+  $: {
+    const newQueryOptions = {}
+
+    if (filterField && filterRelation && filterValue) {
+      newQueryOptions.filter = {
+        field: filterField.value,
+        relation: filterRelation.value,
+        value: filterValue
+      }
+    }
+
+    if (sortField && sortDirection) {
+      newQueryOptions.sort = {
+        field: sortField.value,
+        direction: sortDirection.value
+      }
+    }
+
+    if (pickFields) {
+      newQueryOptions.projection = {
+        fields: pickFields.map(item => item.value)
+      }
+    }
+
+    if (!isEqual(newQueryOptions, queryOptions)) {
+      queryOptions = newQueryOptions
+      const query = createQuery(json, queryOptions)
+      
+      console.log('query updated', query, queryOptions)
+
+      onQuery(query)
+    }
+  }
+</script>
+
+<table class="transform-wizard">
+  <tr>
+    <th>Filter</th>
+    <td>
+      <div class='horizontal'>
+        <Select
+          containerClasses='filter-field'
+          items={fieldOptions} 
+          bind:selectedValue={filterField} 
+        />
+        <Select
+          containerClasses='filter-relation'
+          items={filterRelationOptions} 
+          bind:selectedValue={filterRelation} 
+        />
+        <input
+          class='filter-value'
+          bind:value={filterValue} 
+        />
+      </div>
+    </td>
+  </tr>
+  <tr>
+    <th>Sort</th>
+    <td>
+      <div class='horizontal'>
+        <Select
+          containerClasses='sort-field'
+          items={fieldOptions} 
+          bind:selectedValue={sortField} 
+        />
+        <Select
+          containerClasses='sort-direction'
+          items={sortDirectionOptions} 
+          bind:selectedValue={sortDirection} 
+        />
+      </div>
+    </td>
+  </tr>
+  <tr>
+    <th>Pick</th>
+    <td>
+      <div class='horizontal'>
+        <Select
+          containerClasses='pick-fields'
+          items={fieldOptions}
+          isMulti
+          bind:selectedValue={pickFields} 
+        />
+      </div>
+    </td>
+  </tr>
+</table>
+
+<style src="./TransformWizard.scss"></style>
diff --git a/src/logic/jsCreateQuery.js b/src/logic/jsCreateQuery.js
new file mode 100644
index 0000000..754831f
--- /dev/null
+++ b/src/logic/jsCreateQuery.js
@@ -0,0 +1,47 @@
+import { last } from 'lodash-es'
+
+export function createQuery (json, queryOptions) {
+  console.log('createQuery', queryOptions)
+
+  const { filter, sort, projection } = queryOptions
+  const queryParts = []
+
+  if (filter) {
+    // Note that the comparisons embrace type coercion,
+    // so a filter value like '5' (text) will match numbers like 5 too.
+    const getActualValue = filter.field.length > 0
+      ? `item => _.get(item, ${JSON.stringify(filter.field)})`
+      : 'item => item'
+    queryParts.push(`  data = data.filter(${getActualValue} ${filter.relation} '${filter.value}')\n`)
+  }
+
+  if (sort) {
+    // The '@' field name is a special case,
+    // which means that the field itself is selected.
+    // For example when we have an array containing numbers.
+    if (sort.field !== '@') {
+      queryParts.push(`  data = _.orderBy(data, '${sort.field}', '${sort.direction}')\n`)
+    } else {
+      queryParts.push(`  data = _.sortBy(data, '${sort.direction}')\n`)
+    }
+  }
+
+  if (projection) {
+    // It is possible to make a util function "pickFlat"
+    // and use that when building the query to make it more readable.
+    if (projection.fields.length > 1) {
+      const fields = projection.fields.map(field => {
+        const name = last(field)
+        return `    ${JSON.stringify(name)}: _.get(item, ${JSON.stringify(field)})`
+      })
+      queryParts.push(`  data = data.map(item => ({\n${fields.join(',\n')}})\n  )\n`)
+    } else {
+      const field = projection.fields[0]
+      queryParts.push(`  data = data.map(item => _.get(item, ${JSON.stringify(field)}))\n`)
+    }
+  }
+
+  queryParts.push('  return data\n')
+
+  return `function query (data) {\n${queryParts.join('')}}`
+}