From a11f528227925be325b3fa8154038c2275d93fc3 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 16 Mar 2026 07:58:47 +0000
Subject: [PATCH 1/5] Initial plan


From 7e062541dff794f5a5583af43e7ecf82a24459b2 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 16 Mar 2026 08:04:06 +0000
Subject: [PATCH 2/5] =?UTF-8?q?Add=20WebAssembly=20browser=20build=20and?=
 =?UTF-8?q?=20static=20web=20UI=20for=20OpenAPI=203.0=20=E2=86=92=20Swagge?=
 =?UTF-8?q?r=202.0=20conversion?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Co-authored-by: c6-dev <31777460+c6-dev@users.noreply.github.com>
---
 README.md           |   6 +
 code/Converter.cpp  |  13 ++-
 code/Converter.h    |   2 +
 wasm/CMakeLists.txt |  38 ++++++
 wasm/README.md      |  63 ++++++++++
 wasm/index.html     | 279 ++++++++++++++++++++++++++++++++++++++++++++
 wasm/wasm_entry.cpp |  12 ++
 7 files changed, 411 insertions(+), 2 deletions(-)
 create mode 100644 wasm/CMakeLists.txt
 create mode 100644 wasm/README.md
 create mode 100644 wasm/index.html
 create mode 100644 wasm/wasm_entry.cpp

diff --git a/README.md b/README.md
index 0cde4d7..47e2257 100644
--- a/README.md
+++ b/README.md
@@ -14,3 +14,9 @@ Loosely based on [api-spec-converter](https://github.com/LucyBot-Inc/api-spec-co
 
 Uses [yaml-cpp](https://github.com/jbeder/yaml-cpp).  
 Built using Visual Studio 2022.
+
+### Web Version
+
+A browser-based version is available that runs the conversion entirely client-side via WebAssembly (no server required). It can be hosted on GitHub Pages or any static file host.
+
+See [`wasm/README.md`](wasm/README.md) for build instructions.
diff --git a/code/Converter.cpp b/code/Converter.cpp
index fb0327c..af563af 100644
--- a/code/Converter.cpp
+++ b/code/Converter.cpp
@@ -530,8 +530,7 @@ void Converter::ConvertSecurityDefinitions() {
     input["components"].remove("securitySchemes");
 }
 
-std::string Converter::Convert(const std::string& source) {
-    input = YAML::LoadFile(source);
+std::string Converter::RunConversion() {
     if (input["components"]) {
         components = YAML::Clone(input["components"]);
     }
@@ -567,4 +566,14 @@ std::string Converter::Convert(const std::string& source) {
     std::string str = "swagger: \"2.0\"\n";
     str += out.c_str();
     return str;
+}
+
+std::string Converter::Convert(const std::string& source) {
+    input = YAML::LoadFile(source);
+    return RunConversion();
+}
+
+std::string Converter::ConvertString(const std::string& yamlContent) {
+    input = YAML::Load(yamlContent);
+    return RunConversion();
 }
\ No newline at end of file
diff --git a/code/Converter.h b/code/Converter.h
index c539e35..06e1f84 100644
--- a/code/Converter.h
+++ b/code/Converter.h
@@ -7,7 +7,9 @@
 class Converter {
 public:
     std::string Convert(const std::string& source);
+    std::string ConvertString(const std::string& yamlContent);
 private:
+    std::string RunConversion();
     YAML::Node input;
     YAML::Node components;
     void ConvertInfos();
diff --git a/wasm/CMakeLists.txt b/wasm/CMakeLists.txt
new file mode 100644
index 0000000..61ace02
--- /dev/null
+++ b/wasm/CMakeLists.txt
@@ -0,0 +1,38 @@
+cmake_minimum_required(VERSION 3.15)
+project(openapi-downgrader-wasm)
+
+include(FetchContent)
+
+FetchContent_Declare(
+    yaml-cpp
+    GIT_REPOSITORY https://github.com/jbeder/yaml-cpp.git
+    GIT_TAG        0.8.0
+)
+set(YAML_CPP_BUILD_TESTS OFF CACHE BOOL "" FORCE)
+set(YAML_CPP_BUILD_TOOLS OFF CACHE BOOL "" FORCE)
+set(YAML_CPP_BUILD_CONTRIB OFF CACHE BOOL "" FORCE)
+FetchContent_MakeAvailable(yaml-cpp)
+
+add_executable(downgrader
+    ../code/Converter.cpp
+    ../code/Util.cpp
+    wasm_entry.cpp
+)
+
+target_include_directories(downgrader PRIVATE ../include)
+target_link_libraries(downgrader PRIVATE yaml-cpp)
+
+set_target_properties(downgrader PROPERTIES
+    OUTPUT_NAME "downgrader"
+    SUFFIX ".js"
+)
+
+target_link_options(downgrader PRIVATE
+    --bind
+    -O2
+    -sWASM=1
+    -sALLOW_MEMORY_GROWTH=1
+    -sMODULARIZE=1
+    -sEXPORT_NAME=createModule
+    -sENVIRONMENT=web
+)
diff --git a/wasm/README.md b/wasm/README.md
new file mode 100644
index 0000000..60c2adf
--- /dev/null
+++ b/wasm/README.md
@@ -0,0 +1,63 @@
+# openapi-downgrader — WebAssembly / Browser Build
+
+This directory contains everything needed to build and run the OpenAPI 3.0 → Swagger 2.0 converter **entirely in the browser** using WebAssembly (Emscripten).
+
+## Prerequisites
+
+- [Emscripten SDK](https://emscripten.org/docs/getting_started/downloads.html) (`emcc`/`em++` on your PATH)
+- CMake >= 3.15
+- Git (used by CMake `FetchContent` to download yaml-cpp)
+- Python 3 (for the local dev server)
+
+### Install Emscripten SDK
+
+```bash
+git clone https://github.com/emscripten-core/emsdk.git
+cd emsdk
+./emsdk install latest
+./emsdk activate latest
+source ./emsdk_env.sh   # add to your shell profile for persistence
+```
+
+## Build
+
+Run the following commands from the **repository root**:
+
+```bash
+mkdir build-wasm
+cd build-wasm
+emcmake cmake ../wasm
+cmake --build . -- -j$(nproc)
+```
+
+This will produce `downgrader.js` and `downgrader.wasm` in the `build-wasm/` directory.
+
+After a successful build, copy (or symlink) those two files next to `wasm/index.html`:
+
+```bash
+cp build-wasm/downgrader.js  wasm/
+cp build-wasm/downgrader.wasm wasm/
+```
+
+## Serve locally
+
+Browsers require a proper HTTP server to load `.wasm` files (the `file://` protocol does not work):
+
+```bash
+cd wasm
+python3 -m http.server 8080
+```
+
+Then open <http://localhost:8080> in your browser.
+
+## GitHub Pages hosting
+
+1. After building, commit `wasm/index.html`, `wasm/downgrader.js`, and `wasm/downgrader.wasm` to your repository.
+2. Enable **GitHub Pages** in the repository settings, pointing at the branch/folder that contains the `wasm/` directory (or move the files to `docs/`).
+3. GitHub Pages serves static files with the correct MIME types for `.wasm`, so no extra configuration is needed.
+
+## Notes
+
+- yaml-cpp is fetched automatically by CMake `FetchContent` during configure — no manual download required.
+- The prebuilt `.lib` files in `lib/` are Windows-only and are **not** used by the Wasm build.
+- The conversion runs 100 % client-side; no data is sent to any server.
diff --git a/wasm/index.html b/wasm/index.html
new file mode 100644
index 0000000..f56f698
--- /dev/null
+++ b/wasm/index.html
@@ -0,0 +1,279 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8" />
+  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+  <title>OpenAPI 3.0 → Swagger 2.0 Converter</title>
+  <style>
+    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
+
+    body {
+      font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
+      background: #f5f6fa;
+      color: #333;
+      min-height: 100vh;
+      padding: 1.5rem;
+    }
+
+    header {
+      text-align: center;
+      margin-bottom: 1.5rem;
+    }
+
+    header h1 {
+      font-size: 1.6rem;
+      font-weight: 700;
+    }
+
+    header p {
+      margin-top: 0.4rem;
+      color: #666;
+      font-size: 0.9rem;
+    }
+
+    #loading-banner {
+      background: #fff3cd;
+      border: 1px solid #ffc107;
+      border-radius: 6px;
+      padding: 0.6rem 1rem;
+      margin-bottom: 1rem;
+      font-size: 0.9rem;
+      text-align: center;
+    }
+
+    #loading-banner.hidden { display: none; }
+
+    #error-banner {
+      background: #fdecea;
+      border: 1px solid #f44336;
+      border-radius: 6px;
+      padding: 0.6rem 1rem;
+      margin-bottom: 1rem;
+      font-size: 0.9rem;
+      white-space: pre-wrap;
+      word-break: break-word;
+    }
+
+    #error-banner.hidden { display: none; }
+
+    .grid {
+      display: grid;
+      grid-template-columns: 1fr 1fr;
+      gap: 1.25rem;
+    }
+
+    @media (max-width: 700px) {
+      .grid { grid-template-columns: 1fr; }
+    }
+
+    .panel {
+      background: #fff;
+      border-radius: 8px;
+      box-shadow: 0 1px 4px rgba(0,0,0,0.08);
+      padding: 1rem;
+      display: flex;
+      flex-direction: column;
+      gap: 0.6rem;
+    }
+
+    .panel label {
+      font-weight: 600;
+      font-size: 0.9rem;
+    }
+
+    textarea {
+      width: 100%;
+      height: 380px;
+      font-family: 'Menlo', 'Consolas', monospace;
+      font-size: 0.8rem;
+      border: 1px solid #ddd;
+      border-radius: 6px;
+      padding: 0.6rem;
+      resize: vertical;
+      background: #fafafa;
+    }
+
+    textarea:focus { outline: none; border-color: #4a90e2; }
+
+    .btn-row {
+      display: flex;
+      flex-wrap: wrap;
+      gap: 0.5rem;
+    }
+
+    button, label.file-btn {
+      cursor: pointer;
+      border: none;
+      border-radius: 6px;
+      padding: 0.5rem 1rem;
+      font-size: 0.85rem;
+      font-weight: 600;
+      transition: opacity 0.15s;
+    }
+
+    button:hover, label.file-btn:hover { opacity: 0.85; }
+    button:disabled { opacity: 0.45; cursor: not-allowed; }
+
+    #convert-btn {
+      background: #4a90e2;
+      color: #fff;
+      flex: 1;
+    }
+
+    label.file-btn {
+      background: #e8f0fe;
+      color: #1a56db;
+      display: inline-block;
+    }
+
+    #download-btn {
+      background: #22c55e;
+      color: #fff;
+    }
+
+    #copy-btn {
+      background: #e8f0fe;
+      color: #1a56db;
+    }
+
+    #file-input { display: none; }
+  </style>
+</head>
+<body>
+
+  <header>
+    <h1>OpenAPI 3.0 → Swagger 2.0 Converter</h1>
+    <p>Conversion runs entirely in your browser — no data is uploaded anywhere.</p>
+  </header>
+
+  <div id="loading-banner">⏳ Loading WebAssembly module…</div>
+  <div id="error-banner" class="hidden"></div>
+
+  <div class="grid">
+    <!-- Input panel -->
+    <div class="panel">
+      <label for="input-area">OpenAPI 3.0 input</label>
+      <div class="btn-row">
+        <label class="file-btn" for="file-input">📂 Upload file</label>
+        <input type="file" id="file-input" accept=".yaml,.yml,.json" />
+      </div>
+      <textarea id="input-area" placeholder="Paste OpenAPI 3.0 YAML or JSON here, or upload a file above…" spellcheck="false"></textarea>
+      <div class="btn-row">
+        <button id="convert-btn" disabled>Convert →</button>
+      </div>
+    </div>
+
+    <!-- Output panel -->
+    <div class="panel">
+      <label for="output-area">Swagger 2.0 output</label>
+      <textarea id="output-area" readonly placeholder="Converted Swagger 2.0 YAML will appear here…" spellcheck="false"></textarea>
+      <div class="btn-row">
+        <button id="download-btn" disabled>⬇ Download .yaml</button>
+        <button id="copy-btn" disabled>📋 Copy to clipboard</button>
+      </div>
+    </div>
+  </div>
+
+  <script src="downgrader.js"></script>
+  <script>
+    const loadingBanner = document.getElementById('loading-banner');
+    const errorBanner   = document.getElementById('error-banner');
+    const convertBtn    = document.getElementById('convert-btn');
+    const downloadBtn   = document.getElementById('download-btn');
+    const copyBtn       = document.getElementById('copy-btn');
+    const inputArea     = document.getElementById('input-area');
+    const outputArea    = document.getElementById('output-area');
+    const fileInput     = document.getElementById('file-input');
+
+    let wasmModule = null;
+
+    function showError(msg) {
+      errorBanner.textContent = msg;
+      errorBanner.classList.remove('hidden');
+    }
+
+    function clearError() {
+      errorBanner.textContent = '';
+      errorBanner.classList.add('hidden');
+    }
+
+    // Initialise the Wasm module
+    createModule().then(function(mod) {
+      wasmModule = mod;
+      loadingBanner.classList.add('hidden');
+      convertBtn.disabled = false;
+    }).catch(function(err) {
+      loadingBanner.classList.add('hidden');
+      showError('Failed to load WebAssembly module: ' + (err && err.message ? err.message : String(err)));
+    });
+
+    // File upload
+    fileInput.addEventListener('change', function() {
+      const file = fileInput.files[0];
+      if (!file) return;
+      const reader = new FileReader();
+      reader.onload = function(e) {
+        inputArea.value = e.target.result;
+        clearError();
+      };
+      reader.onerror = function() { showError('Failed to read file.'); };
+      reader.readAsText(file);
+      // Reset so the same file can be re-uploaded
+      fileInput.value = '';
+    });
+
+    // Convert
+    convertBtn.addEventListener('click', function() {
+      clearError();
+      outputArea.value = '';
+      downloadBtn.disabled = true;
+      copyBtn.disabled = true;
+
+      const yaml = inputArea.value.trim();
+      if (!yaml) {
+        showError('Please paste or upload an OpenAPI 3.0 spec first.');
+        return;
+      }
+
+      try {
+        const result = wasmModule.convert(yaml);
+        outputArea.value = result;
+        downloadBtn.disabled = false;
+        copyBtn.disabled = false;
+      } catch (err) {
+        showError('Conversion error: ' + (err && err.message ? err.message : String(err)));
+      }
+    });
+
+    // Download
+    downloadBtn.addEventListener('click', function() {
+      const content = outputArea.value;
+      if (!content) return;
+      const blob = new Blob([content], { type: 'application/yaml' });
+      const url  = URL.createObjectURL(blob);
+      const a    = document.createElement('a');
+      a.href     = url;
+      a.download = 'swagger2.yaml';
+      a.click();
+      URL.revokeObjectURL(url);
+    });
+
+    // Copy to clipboard
+    copyBtn.addEventListener('click', function() {
+      const content = outputArea.value;
+      if (!content) return;
+      if (navigator.clipboard && navigator.clipboard.writeText) {
+        navigator.clipboard.writeText(content).then(function() {
+          const original = copyBtn.textContent;
+          copyBtn.textContent = '✅ Copied!';
+          setTimeout(function() { copyBtn.textContent = original; }, 1500);
+        }).catch(function() {
+          showError('Clipboard write failed. Please copy the output manually.');
+        });
+      } else {
+        showError('Clipboard API not available in this browser. Please select and copy the output manually.');
+      }
+    });
+  </script>
+</body>
+</html>
diff --git a/wasm/wasm_entry.cpp b/wasm/wasm_entry.cpp
new file mode 100644
index 0000000..bb52f46
--- /dev/null
+++ b/wasm/wasm_entry.cpp
@@ -0,0 +1,12 @@
+#include "../code/Converter.h"
+#include <emscripten/bind.h>
+#include <stdexcept>
+
+std::string convert(std::string yamlInput) {
+    Converter converter;
+    return converter.ConvertString(yamlInput);
+}
+
+EMSCRIPTEN_BINDINGS(openapi_downgrader) {
+    emscripten::function("convert", &convert);
+}

From c8d5db5ab400ae0f03278c69c9d5f93b1e6bd251 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 16 Mar 2026 08:13:24 +0000
Subject: [PATCH 3/5] Add GitHub Actions workflow to build the WebAssembly
 version

Co-authored-by: c6-dev <31777460+c6-dev@users.noreply.github.com>
---
 .github/workflows/build-wasm.yml | 75 ++++++++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)
 create mode 100644 .github/workflows/build-wasm.yml

diff --git a/.github/workflows/build-wasm.yml b/.github/workflows/build-wasm.yml
new file mode 100644
index 0000000..1ea6602
--- /dev/null
+++ b/.github/workflows/build-wasm.yml
@@ -0,0 +1,75 @@
+name: Build WebAssembly
+
+on:
+  push:
+    branches: [main, master]
+    paths:
+      - 'code/**'
+      - 'wasm/**'
+  pull_request:
+    paths:
+      - 'code/**'
+      - 'wasm/**'
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    name: Build Wasm
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Emscripten SDK
+        uses: mymindstorm/setup-emsdk@v14
+
+      - name: Configure (emcmake cmake)
+        run: emcmake cmake -S wasm -B build-wasm
+
+      - name: Build
+        run: cmake --build build-wasm -j$(nproc)
+
+      - name: Prepare distribution files
+        run: |
+          mkdir -p dist
+          cp wasm/index.html        dist/
+          cp build-wasm/downgrader.js   dist/
+          cp build-wasm/downgrader.wasm dist/
+
+      - name: Upload build artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: wasm-dist
+          path: dist/
+          if-no-files-found: error
+
+  deploy:
+    name: Deploy to GitHub Pages
+    needs: build
+    if: github.event_name == 'push' && (github.ref == 'refs/heads/main' || github.ref == 'refs/heads/master')
+    runs-on: ubuntu-latest
+    permissions:
+      pages: write
+      id-token: write
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+
+    steps:
+      - name: Download build artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: wasm-dist
+          path: dist/
+
+      - name: Upload Pages artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: dist/
+
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4

From c1eb5ad0a50c5b7d191dc3747733e90dcc38f277 Mon Sep 17 00:00:00 2001
From: c6 <31777460+c6-dev@users.noreply.github.com>
Date: Mon, 16 Mar 2026 13:57:34 +0400
Subject: [PATCH 4/5] Rename header include from converter.h to Converter.h

---
 code/Converter.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/code/Converter.cpp b/code/Converter.cpp
index af563af..a250cd5 100644
--- a/code/Converter.cpp
+++ b/code/Converter.cpp
@@ -1,4 +1,4 @@
-#include "converter.h"
+#include "Converter.h"
 #include "Util.h"
 #include <iostream>
 #include <regex>
@@ -576,4 +576,4 @@ std::string Converter::Convert(const std::string& source) {
 std::string Converter::ConvertString(const std::string& yamlContent) {
     input = YAML::Load(yamlContent);
     return RunConversion();
-}
\ No newline at end of file
+}

From 9ae8bac7af67faaeed66710cb8d8bcfafbf8dd2a Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 16 Mar 2026 10:09:11 +0000
Subject: [PATCH 5/5] Fix panel height misalignment in index.html

Co-authored-by: c6-dev <31777460+c6-dev@users.noreply.github.com>
---
 wasm/index.html | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/wasm/index.html b/wasm/index.html
index f56f698..69cd927 100644
--- a/wasm/index.html
+++ b/wasm/index.html
@@ -76,7 +76,15 @@
       gap: 0.6rem;
     }
 
-    .panel label {
+    .panel-header {
+      display: flex;
+      align-items: center;
+      justify-content: space-between;
+      gap: 0.5rem;
+      min-height: calc(0.85rem * 1.2 + 1rem); /* matches button height (padding + line-height) */
+    }
+
+    .panel-header label {
       font-weight: 600;
       font-size: 0.9rem;
     }
@@ -152,8 +160,8 @@ <h1>OpenAPI 3.0 → Swagger 2.0 Converter</h1>
   <div class="grid">
     <!-- Input panel -->
     <div class="panel">
-      <label for="input-area">OpenAPI 3.0 input</label>
-      <div class="btn-row">
+      <div class="panel-header">
+        <label for="input-area">OpenAPI 3.0 input</label>
         <label class="file-btn" for="file-input">📂 Upload file</label>
         <input type="file" id="file-input" accept=".yaml,.yml,.json" />
       </div>
@@ -165,7 +173,9 @@ <h1>OpenAPI 3.0 → Swagger 2.0 Converter</h1>
 
     <!-- Output panel -->
     <div class="panel">
-      <label for="output-area">Swagger 2.0 output</label>
+      <div class="panel-header">
+        <label for="output-area">Swagger 2.0 output</label>
+      </div>
       <textarea id="output-area" readonly placeholder="Converted Swagger 2.0 YAML will appear here…" spellcheck="false"></textarea>
       <div class="btn-row">
         <button id="download-btn" disabled>⬇ Download .yaml</button>