feat: add download features to llm models

backend/internal/api/handlers/admin.go

@@ -1,6 +1,7 @@
 package handlers
 
 import (
+	"context"
 	"fmt"
 	"net/http"
 
@@ -330,6 +331,118 @@ func (h *Handler) GetDefaultSystemPrompt(c *gin.Context) {
 	httputil.OK(c, gin.H{"prompt": ai.DefaultSystemPrompt})
 }
 
+// ── AI Roles ───────────────────────────────────────────────────────────────
+
+func (h *Handler) GetAIRoles(c *gin.Context) {
+	roles := []string{"summary", "report", "filter"}
+	resp := gin.H{}
+	for _, role := range roles {
+		providerID, _ := h.repo.GetSetting("ai_role_" + role + "_provider")
+		model, _ := h.repo.GetSetting("ai_role_" + role + "_model")
+		resp[role] = gin.H{"provider_id": providerID, "model": model}
+	}
+	httputil.OK(c, resp)
+}
+
+type updateAIRoleRequest struct {
+	ProviderID string `json:"provider_id"`
+	Model      string `json:"model"`
+}
+
+func (h *Handler) UpdateAIRole(c *gin.Context) {
+	role := c.Param("role")
+	if role != "summary" && role != "report" && role != "filter" {
+		httputil.BadRequest(c, fmt.Errorf("invalid role: must be summary, report, or filter"))
+		return
+	}
+	var req updateAIRoleRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		httputil.BadRequest(c, err)
+		return
+	}
+	if err := h.repo.SetRoleProvider(role, req.ProviderID, req.Model); err != nil {
+		httputil.InternalError(c, err)
+		return
+	}
+	httputil.OK(c, gin.H{"ok": true})
+}
+
+// ── Ollama Model Management ────────────────────────────────────────────────
+
+func (h *Handler) getOllamaManager() (*ai.OllamaProvider, error) {
+	providers, err := h.repo.ListAIProviders()
+	if err != nil {
+		return nil, err
+	}
+	endpoint := ""
+	for _, p := range providers {
+		if p.Name == "ollama" {
+			endpoint = p.Endpoint
+			break
+		}
+	}
+	if endpoint == "" {
+		endpoint = "http://ollama:11434"
+	}
+	return ai.NewOllamaManager(endpoint), nil
+}
+
+func (h *Handler) ListOllamaModels(c *gin.Context) {
+	mgr, err := h.getOllamaManager()
+	if err != nil {
+		httputil.InternalError(c, err)
+		return
+	}
+	models, err := mgr.ListModelsDetailed(c.Request.Context())
+	if err != nil {
+		httputil.InternalError(c, err)
+		return
+	}
+	if models == nil {
+		models = []ai.OllamaModelInfo{}
+	}
+	httputil.OK(c, models)
+}
+
+type pullModelRequest struct {
+	Name string `json:"name" binding:"required"`
+}
+
+func (h *Handler) PullOllamaModel(c *gin.Context) {
+	var req pullModelRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		httputil.BadRequest(c, err)
+		return
+	}
+	mgr, err := h.getOllamaManager()
+	if err != nil {
+		httputil.InternalError(c, err)
+		return
+	}
+	go func() {
+		if err := mgr.PullModel(context.Background(), req.Name); err != nil {
+			fmt.Printf("[ollama] pull %s failed: %v\n", req.Name, err)
+		} else {
+			fmt.Printf("[ollama] pull %s completed\n", req.Name)
+		}
+	}()
+	c.JSON(202, gin.H{"ok": true, "message": "pull started"})
+}
+
+func (h *Handler) DeleteOllamaModel(c *gin.Context) {
+	name := c.Param("name")
+	mgr, err := h.getOllamaManager()
+	if err != nil {
+		httputil.InternalError(c, err)
+		return
+	}
+	if err := mgr.DeleteModel(c.Request.Context(), name); err != nil {
+		httputil.InternalError(c, err)
+		return
+	}
+	httputil.NoContent(c)
+}
+
 // ── Admin Users ────────────────────────────────────────────────────────────
 
 func (h *Handler) ListUsers(c *gin.Context) {