From 1e8f7d366267e83f3de35088c3291bb05ea3d749 Mon Sep 17 00:00:00 2001
From: stuzer05 <stuzer05@stuzer.link>
Date: Thu, 14 Mar 2024 11:10:56 +0200
Subject: [PATCH] #10 Add Go JSON to struct tool (#11)

Closes #10

Reviewed-on: https://gitea.stuzer.link/stuzer05/random-web-tools/pulls/11
Co-authored-by: stuzer05 <stuzer05@stuzer.link>
Co-committed-by: stuzer05 <stuzer05@stuzer.link>
---
 src/components/Sidebar.vue   |   3 +
 src/router/index.js          |   9 +
 src/views/GoJSONToStruct.vue | 501 +++++++++++++++++++++++++++++++++++
 3 files changed, 513 insertions(+)
 create mode 100644 src/views/GoJSONToStruct.vue

diff --git a/src/components/Sidebar.vue b/src/components/Sidebar.vue
index 3fa17e0..babf75e 100644
--- a/src/components/Sidebar.vue
+++ b/src/components/Sidebar.vue
@@ -42,6 +42,9 @@ export default {
         'str_to_php_array': 'Str to PHP array',
         'php_array_to_json': 'PHP array to Json',
       },
+      'GO': {
+        'go_json_to_struct': 'JSON to Go struct',
+      },
       'JSON': {
         'json_formatter': 'JSON formatter',
       },
diff --git a/src/router/index.js b/src/router/index.js
index 838b29a..e3dbe3e 100644
--- a/src/router/index.js
+++ b/src/router/index.js
@@ -75,6 +75,15 @@ const router = createRouter({
 			component: () => import('../views/JSONFormatter.vue'),
 		},
 
+		/**
+		 * Golang
+		 */
+		{
+			path: '/go_json_to_struct',
+			name: 'go_json_to_struct',
+			component: () => import('../views/GoJSONToStruct.vue'),
+		},
+
 		/**
 		 * SQL manipulation
 		 */
diff --git a/src/views/GoJSONToStruct.vue b/src/views/GoJSONToStruct.vue
new file mode 100644
index 0000000..489c703
--- /dev/null
+++ b/src/views/GoJSONToStruct.vue
@@ -0,0 +1,501 @@
+<template>
+  <h2 class="tool-title">Go JSON to struct</h2>
+  <hr class="mt-5 mb-5">
+
+  <div class="input-group">
+    <label for="data">Data</label>
+    <textarea id="data" v-model="toolData.data" v-on:keyup="result"></textarea>
+  </div>
+
+  <div class="input-group">
+    <div>
+      <input id="flatten" name="flatten" v-model="toolData.flatten" v-on:change="result" type="checkbox"> <label for="flatten">inline type definitions</label>
+    </div>
+    <div>
+      <input id="omitempty" name="omitempty" v-model="toolData.omitempty" v-on:change="result" type="checkbox"> <label for="omitempty">omitempty</label>
+    </div>
+  </div>
+
+  <hr class="mt-5 mb-5">
+
+  <div class="input-group">
+    <label for="result">Result</label>
+    <MonacoEditor name="result" language="json" :value="toolResult"></MonacoEditor>
+  </div>
+</template>
+
+<script>
+import MonacoEditor from "@/components/MonacoEditor.vue";
+
+// https://github.com/mholt/json-to-go
+function jsonToGo(json, typename, flatten = true, example = false, allOmitempty = false) {
+  let data;
+  let scope;
+  let go = "";
+  let tabs = 0;
+
+  const seen = {};
+  const stack = [];
+  let accumulator = "";
+  let innerTabs = 0;
+  let parent = "";
+
+  try
+  {
+    data = JSON.parse(json.replace(/(:\s*\[?\s*-?\d*)\.0/g, "$1.1")); // hack that forces floats to stay as floats
+    scope = data;
+  }
+  catch (e)
+  {
+    return {
+      go: "",
+      error: e.message
+    };
+  }
+
+  typename = format(typename || "AutoGenerated");
+  append(`type ${typename} `);
+
+  parseScope(scope);
+
+  return {
+    go: flatten
+      ? go += accumulator
+      : go
+  };
+
+
+  function parseScope(scope, depth = 0)
+  {
+    if (typeof scope === "object" && scope !== null)
+    {
+      if (Array.isArray(scope))
+      {
+        let sliceType;
+        const scopeLength = scope.length;
+
+        for (let i = 0; i < scopeLength; i++)
+        {
+          const thisType = goType(scope[i]);
+          if (!sliceType)
+            sliceType = thisType;
+          else if (sliceType != thisType)
+          {
+            sliceType = mostSpecificPossibleGoType(thisType, sliceType);
+            if (sliceType == "any")
+              break;
+          }
+        }
+
+        const slice = flatten && ["struct", "slice"].includes(sliceType)
+          ? `[]${parent}`
+          : `[]`;
+
+        if (flatten && depth >= 2)
+          appender(slice);
+        else
+          append(slice)
+        if (sliceType == "struct") {
+          const allFields = {};
+
+          // for each field counts how many times appears
+          for (let i = 0; i < scopeLength; i++)
+          {
+            const keys = Object.keys(scope[i])
+            for (let k in keys)
+            {
+              let keyname = keys[k];
+              if (!(keyname in allFields)) {
+                allFields[keyname] = {
+                  value: scope[i][keyname],
+                  count: 0
+                }
+              }
+              else {
+                const existingValue = allFields[keyname].value;
+                const currentValue = scope[i][keyname];
+
+                if (compareObjects(existingValue, currentValue)) {
+                  const comparisonResult = compareObjectKeys(
+                    Object.keys(currentValue),
+                    Object.keys(existingValue)
+                  )
+                  if (!comparisonResult) {
+                    keyname = `${keyname}_${uuidv4()}`;
+                    allFields[keyname] = {
+                      value: currentValue,
+                      count: 0
+                    };
+                  }
+                }
+              }
+              allFields[keyname].count++;
+            }
+          }
+
+          // create a common struct with all fields found in the current array
+          // omitempty dict indicates if a field is optional
+          const keys = Object.keys(allFields), struct = {}, omitempty = {};
+          for (let k in keys)
+          {
+            const keyname = keys[k], elem = allFields[keyname];
+
+            struct[keyname] = elem.value;
+            omitempty[keyname] = elem.count != scopeLength;
+          }
+          parseStruct(depth + 1, innerTabs, struct, omitempty); // finally parse the struct !!
+        }
+        else if (sliceType == "slice") {
+          parseScope(scope[0], depth)
+        }
+        else {
+          if (flatten && depth >= 2) {
+            appender(sliceType || "any");
+          } else {
+            append(sliceType || "any");
+          }
+        }
+      }
+      else
+      {
+        if (flatten) {
+          if (depth >= 2){
+            appender(parent)
+          }
+          else {
+            append(parent)
+          }
+        }
+        parseStruct(depth + 1, innerTabs, scope);
+      }
+    }
+    else {
+      if (flatten && depth >= 2){
+        appender(goType(scope));
+      }
+      else {
+        append(goType(scope));
+      }
+    }
+  }
+
+  function parseStruct(depth, innerTabs, scope, omitempty)
+  {
+    if (flatten) {
+      stack.push(
+        depth >= 2
+          ? "\n"
+          : ""
+      )
+    }
+
+    const seenTypeNames = [];
+
+    if (flatten && depth >= 2)
+    {
+      const parentType = `type ${parent}`;
+      const scopeKeys = formatScopeKeys(Object.keys(scope));
+
+      // this can only handle two duplicate items
+      // future improvement will handle the case where there could
+      // three or more duplicate keys with different values
+      if (parent in seen && compareObjectKeys(scopeKeys, seen[parent])) {
+        stack.pop();
+        return
+      }
+      seen[parent] = scopeKeys;
+
+      appender(`${parentType} struct {\n`);
+      ++innerTabs;
+      const keys = Object.keys(scope);
+      for (let i in keys)
+      {
+        const keyname = getOriginalName(keys[i]);
+        indenter(innerTabs)
+        const typename = uniqueTypeName(format(keyname), seenTypeNames)
+        seenTypeNames.push(typename)
+
+        appender(typename+" ");
+        parent = typename
+        parseScope(scope[keys[i]], depth);
+        appender(' `json:"'+keyname);
+        if (allOmitempty || (omitempty && omitempty[keys[i]] === true))
+        {
+          appender(',omitempty');
+        }
+        appender('"`\n');
+      }
+      indenter(--innerTabs);
+      appender("}");
+    }
+    else
+    {
+      append("struct {\n");
+      ++tabs;
+      const keys = Object.keys(scope);
+      for (let i in keys)
+      {
+        const keyname = getOriginalName(keys[i]);
+        indent(tabs);
+        const typename = uniqueTypeName(format(keyname), seenTypeNames)
+        seenTypeNames.push(typename)
+        append(typename+" ");
+        parent = typename
+        parseScope(scope[keys[i]], depth);
+        append(' `json:"'+keyname);
+        if (allOmitempty || (omitempty && omitempty[keys[i]] === true))
+        {
+          append(',omitempty');
+        }
+        if (example && scope[keys[i]] !== "" && typeof scope[keys[i]] !== "object")
+        {
+          append('" example:"'+scope[keys[i]])
+        }
+        append('"`\n');
+      }
+      indent(--tabs);
+      append("}");
+    }
+    if (flatten)
+      accumulator += stack.pop();
+  }
+
+  function indent(tabs)
+  {
+    for (let i = 0; i < tabs; i++)
+      go += '\t';
+  }
+
+  function append(str)
+  {
+    go += str;
+  }
+
+  function indenter(tabs)
+  {
+    for (let i = 0; i < tabs; i++)
+      stack[stack.length - 1] += '\t';
+  }
+
+  function appender(str)
+  {
+    stack[stack.length - 1] += str;
+  }
+
+  // Generate a unique name to avoid duplicate struct field names.
+  // This function appends a number at the end of the field name.
+  function uniqueTypeName(name, seen) {
+    if (seen.indexOf(name) === -1) {
+      return name;
+    }
+
+    let i = 0;
+    while (true) {
+      let newName = name + i.toString();
+      if (seen.indexOf(newName) === -1) {
+        return newName;
+      }
+
+      i++;
+    }
+  }
+
+  // Sanitizes and formats a string to make an appropriate identifier in Go
+  function format(str)
+  {
+    str = formatNumber(str);
+
+    let sanitized = toProperCase(str).replace(/[^a-z0-9]/ig, "")
+    if (!sanitized) {
+      return "NAMING_FAILED";
+    }
+
+    // After sanitizing the remaining characters can start with a number.
+    // Run the sanitized string again trough formatNumber to make sure the identifier is Num[0-9] or Zero_... instead of 1.
+    return formatNumber(sanitized)
+  }
+
+  // Adds a prefix to a number to make an appropriate identifier in Go
+  function formatNumber(str) {
+    if (!str)
+      return "";
+    else if (str.match(/^\d+$/))
+      str = "Num" + str;
+    else if (str.charAt(0).match(/\d/))
+    {
+      const numbers = {'0': "Zero_", '1': "One_", '2': "Two_", '3': "Three_",
+        '4': "Four_", '5': "Five_", '6': "Six_", '7': "Seven_",
+        '8': "Eight_", '9': "Nine_"};
+      str = numbers[str.charAt(0)] + str.substr(1);
+    }
+
+    return str;
+  }
+
+  // Determines the most appropriate Go type
+  function goType(val)
+  {
+    if (val === null)
+      return "any";
+
+    switch (typeof val)
+    {
+      case "string":
+        if (/^\d{4}-\d\d-\d\dT\d\d:\d\d:\d\d(\.\d+)?(\+\d\d:\d\d|Z)$/.test(val))
+          return "time.Time";
+        else
+          return "string";
+      case "number":
+        if (val % 1 === 0)
+        {
+          if (val > -2147483648 && val < 2147483647)
+            return "int";
+          else
+            return "int64";
+        }
+        else
+          return "float64";
+      case "boolean":
+        return "bool";
+      case "object":
+        if (Array.isArray(val))
+          return "slice";
+        return "struct";
+      default:
+        return "any";
+    }
+  }
+
+  // Given two types, returns the more specific of the two
+  function mostSpecificPossibleGoType(typ1, typ2)
+  {
+    if (typ1.substr(0, 5) == "float"
+      && typ2.substr(0, 3) == "int")
+      return typ1;
+    else if (typ1.substr(0, 3) == "int"
+      && typ2.substr(0, 5) == "float")
+      return typ2;
+    else
+      return "any";
+  }
+
+  // Proper cases a string according to Go conventions
+  function toProperCase(str)
+  {
+    // ensure that the SCREAMING_SNAKE_CASE is converted to snake_case
+    if (str.match(/^[_A-Z0-9]+$/)) {
+      str = str.toLowerCase();
+    }
+
+    // https://github.com/golang/lint/blob/5614ed5bae6fb75893070bdc0996a68765fdd275/lint.go#L771-L810
+    const commonInitialisms = [
+      "ACL", "API", "ASCII", "CPU", "CSS", "DNS", "EOF", "GUID", "HTML", "HTTP",
+      "HTTPS", "ID", "IP", "JSON", "LHS", "QPS", "RAM", "RHS", "RPC", "SLA",
+      "SMTP", "SQL", "SSH", "TCP", "TLS", "TTL", "UDP", "UI", "UID", "UUID",
+      "URI", "URL", "UTF8", "VM", "XML", "XMPP", "XSRF", "XSS"
+    ];
+
+    return str.replace(/(^|[^a-zA-Z])([a-z]+)/g, function(unused, sep, frag)
+    {
+      if (commonInitialisms.indexOf(frag.toUpperCase()) >= 0)
+        return sep + frag.toUpperCase();
+      else
+        return sep + frag[0].toUpperCase() + frag.substr(1).toLowerCase();
+    }).replace(/([A-Z])([a-z]+)/g, function(unused, sep, frag)
+    {
+      if (commonInitialisms.indexOf(sep + frag.toUpperCase()) >= 0)
+        return (sep + frag).toUpperCase();
+      else
+        return sep + frag;
+    });
+  }
+
+  function uuidv4() {
+    return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
+      var r = Math.random() * 16 | 0, v = c == 'x' ? r : (r & 0x3 | 0x8);
+      return v.toString(16);
+    });
+  }
+
+  function getOriginalName(unique) {
+    const reLiteralUUID = /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i
+    const uuidLength = 36;
+
+    if (unique.length >= uuidLength) {
+      const tail = unique.substr(-uuidLength);
+      if (reLiteralUUID.test(tail)) {
+        return unique.slice(0, -1 * (uuidLength + 1))
+      }
+    }
+    return unique
+  }
+
+  function compareObjects(objectA, objectB) {
+    const object = "[object Object]";
+    return Object.prototype.toString.call(objectA) === object
+      && Object.prototype.toString.call(objectB) === object;
+  }
+
+  function compareObjectKeys(itemAKeys, itemBKeys) {
+    const lengthA = itemAKeys.length;
+    const lengthB = itemBKeys.length;
+
+    // nothing to compare, probably identical
+    if (lengthA == 0 && lengthB == 0)
+      return true;
+
+    // duh
+    if (lengthA != lengthB)
+      return false;
+
+    for (let item of itemAKeys) {
+      if (!itemBKeys.includes(item))
+        return false;
+    }
+    return true;
+  }
+
+  function formatScopeKeys(keys) {
+    for (let i in keys) {
+      keys[i] = format(keys[i]);
+    }
+    return keys
+  }
+}
+
+export default {
+  components: {
+    MonacoEditor
+  },
+  data() {
+    return {
+      toolData: {
+        data: '',
+        flatten: false,
+        omitempty: false,
+      },
+      toolResult: '',
+    };
+  },
+  methods: {
+    result() {
+      if (!this.toolData.data.length) {
+        this.toolResult = '';
+        return;
+      }
+
+      const json = jsonToGo(this.toolData.data, "", this.toolData.flatten, false, this.toolData.omitempty);
+      if (json.error?.length) {
+        this.toolResult = 'invalid json';
+        return;
+      }
+
+      this.toolResult = json.go;
+    }
+  },
+}
+</script>
+
+<style lang="scss">
+
+</style>
\ No newline at end of file