feat: re-integrate Java download UI into new component architecture

- Add Java download functionality to settings store
- Add JavaDownloadInfo type definition
- Add Download Java button and modal to SettingsView
- Support JRE/JDK selection with version picker
- Maintain integration with Adoptium API backend

3 files changed, 149 insertions, 1 deletions

diff --git a/ui/src/components/SettingsView.svelte b/ui/src/components/SettingsView.svelte
index 86bcce1..d409784 100644
--- a/ui/src/components/SettingsView.svelte
+++ b/ui/src/components/SettingsView.svelte
@@ -183,6 +183,12 @@
                 >
                 {settingsState.isDetectingJava ? "Detecting..." : "Auto Detect"}
                 </button>
+                <button
+                onclick={() => settingsState.openJavaDownloadModal()}
+                class="bg-indigo-600 hover:bg-indigo-500 text-white px-4 py-2 rounded-xl transition-colors whitespace-nowrap text-sm font-medium"
+                >
+                Download Java
+                </button>
             </div>
         </div>
       
@@ -297,3 +303,74 @@
     </div>
   </div>
 </div>
+
+<!-- Java Download Modal -->
+{#if settingsState.showJavaDownloadModal}
+  <div class="fixed inset-0 z-[100] flex items-center justify-center backdrop-blur-sm bg-black/70">
+    <div class="bg-zinc-900 rounded-2xl border border-white/10 p-8 max-w-md w-full mx-4 shadow-2xl">
+      <h3 class="text-2xl font-bold mb-6 text-white">Download Java</h3>
+      
+      <div class="space-y-6">
+        <!-- Java Version Selection -->
+        <div>
+          <label class="block text-sm font-medium text-white/70 mb-2">Java Version</label>
+          <select
+            bind:value={settingsState.selectedJavaVersion}
+            class="bg-black/40 text-white w-full px-4 py-3 rounded-xl border border-white/10 focus:border-indigo-500/50 outline-none"
+          >
+            {#each settingsState.availableJavaVersions as version}
+              <option value={version}>Java {version}</option>
+            {/each}
+          </select>
+        </div>
+
+        <!-- Image Type Selection -->
+        <div>
+          <label class="block text-sm font-medium text-white/70 mb-2">Image Type</label>
+          <div class="grid grid-cols-2 gap-3">
+            <button
+              onclick={() => settingsState.selectedImageType = "jre"}
+              class="px-4 py-3 rounded-xl border transition-all {settingsState.selectedImageType === 'jre' ? 'bg-indigo-500/20 border-indigo-500/50 text-white' : 'bg-black/20 border-white/10 text-white/60 hover:bg-white/5'}"
+            >
+              JRE
+            </button>
+            <button
+              onclick={() => settingsState.selectedImageType = "jdk"}
+              class="px-4 py-3 rounded-xl border transition-all {settingsState.selectedImageType === 'jdk' ? 'bg-indigo-500/20 border-indigo-500/50 text-white' : 'bg-black/20 border-white/10 text-white/60 hover:bg-white/5'}"
+            >
+              JDK
+            </button>
+          </div>
+          <p class="text-xs text-white/40 mt-2">
+            JRE: Runtime only (smaller). JDK: Includes development tools.
+          </p>
+        </div>
+
+        <!-- Status -->
+        {#if settingsState.javaDownloadStatus}
+          <div class="bg-black/40 border border-white/10 rounded-xl p-4 text-sm text-white/80">
+            {settingsState.javaDownloadStatus}
+          </div>
+        {/if}
+
+        <!-- Actions -->
+        <div class="flex gap-3 pt-2">
+          <button
+            onclick={() => settingsState.closeJavaDownloadModal()}
+            disabled={settingsState.isDownloadingJava}
+            class="flex-1 bg-white/10 hover:bg-white/20 disabled:opacity-50 text-white px-4 py-3 rounded-xl border border-white/5 transition-colors font-medium"
+          >
+            Cancel
+          </button>
+          <button
+            onclick={() => settingsState.downloadJava()}
+            disabled={settingsState.isDownloadingJava}
+            class="flex-1 bg-indigo-600 hover:bg-indigo-500 disabled:opacity-50 text-white px-4 py-3 rounded-xl transition-colors font-medium"
+          >
+            {settingsState.isDownloadingJava ? "Downloading..." : "Download & Install"}
+          </button>
+        </div>
+      </div>
+    </div>
+  </div>
+{/if}
diff --git a/ui/src/stores/settings.svelte.ts b/ui/src/stores/settings.svelte.ts
index b67cdc3..34b6b4c 100644
--- a/ui/src/stores/settings.svelte.ts
+++ b/ui/src/stores/settings.svelte.ts
@@ -1,5 +1,5 @@
 import { invoke } from "@tauri-apps/api/core";
-import type { LauncherConfig, JavaInstallation } from "../types";
+import type { LauncherConfig, JavaInstallation, JavaDownloadInfo } from "../types";
 import { uiState } from "./ui.svelte";
 
 export class SettingsState {
@@ -17,6 +17,14 @@ export class SettingsState {
   });
   javaInstallations = $state<JavaInstallation[]>([]);
   isDetectingJava = $state(false);
+  
+  // Java download state
+  showJavaDownloadModal = $state(false);
+  availableJavaVersions = $state<number[]>([]);
+  selectedJavaVersion = $state(21);
+  selectedImageType = $state<"jre" | "jdk">("jre");
+  isDownloadingJava = $state(false);
+  javaDownloadStatus = $state("");
 
   async loadSettings() {
     try {
@@ -62,6 +70,59 @@ export class SettingsState {
   selectJava(path: string) {
     this.settings.java_path = path;
   }
+
+  async openJavaDownloadModal() {
+    this.showJavaDownloadModal = true;
+    this.javaDownloadStatus = "";
+    try {
+      this.availableJavaVersions = await invoke("fetch_available_java_versions");
+      // Default selection logic
+      if (this.availableJavaVersions.includes(21)) {
+        this.selectedJavaVersion = 21;
+      } else if (this.availableJavaVersions.includes(17)) {
+        this.selectedJavaVersion = 17;
+      } else if (this.availableJavaVersions.length > 0) {
+        this.selectedJavaVersion = this.availableJavaVersions[this.availableJavaVersions.length - 1];
+      }
+    } catch (e) {
+      console.error("Failed to fetch available Java versions:", e);
+      this.javaDownloadStatus = "Error fetching Java versions: " + e;
+    }
+  }
+
+  closeJavaDownloadModal() {
+    if (!this.isDownloadingJava) {
+      this.showJavaDownloadModal = false;
+    }
+  }
+
+  async downloadJava() {
+    this.isDownloadingJava = true;
+    this.javaDownloadStatus = `Downloading Java ${this.selectedJavaVersion} ${this.selectedImageType.toUpperCase()}...`;
+    
+    try {
+      const result: JavaInstallation = await invoke("download_adoptium_java", {
+        majorVersion: this.selectedJavaVersion,
+        imageType: this.selectedImageType,
+        customPath: null,
+      });
+      
+      this.javaDownloadStatus = `Java ${this.selectedJavaVersion} installed at ${result.path}`;
+      this.settings.java_path = result.path;
+      
+      await this.detectJava();
+      
+      setTimeout(() => {
+        this.showJavaDownloadModal = false;
+        uiState.setStatus(`Java ${this.selectedJavaVersion} is ready to use!`);
+      }, 1500);
+    } catch (e) {
+      console.error("Failed to download Java:", e);
+      this.javaDownloadStatus = "Download failed: " + e;
+    } finally {
+      this.isDownloadingJava = false;
+    }
+  }
 }
 
 export const settingsState = new SettingsState();
diff --git a/ui/src/types/index.ts b/ui/src/types/index.ts
index 7e2cc67..f92cbf2 100644
--- a/ui/src/types/index.ts
+++ b/ui/src/types/index.ts
@@ -43,6 +43,16 @@ export interface JavaInstallation {
   is_64bit: boolean;
 }
 
+export interface JavaDownloadInfo {
+  version: string;
+  release_name: string;
+  download_url: string;
+  file_name: string;
+  file_size: number;
+  checksum: string | null;
+  image_type: string;
+}
+
 // ==================== Fabric Types ====================
 
 export interface FabricGameVersion {