Refactor collaborator add/remove to use API endpoints

Updated the logic for adding and removing project collaborators to use REST API endpoints instead of direct database calls. This simplifies the frontend code, improves error handling, and ensures collaborator lists are refreshed using API responses.

Author: DongDuong2001

app/dashboard/projects/page.tsx

@@ -243,63 +243,50 @@ export default function ProjectsPage() {
       setLoading(true)
       setError(null)
 
-      console.log('🔍 Searching for user with email:', collaboratorEmail)
-
-      // Find user by email (case-insensitive, trimmed)
-      const userProfile = await getProfileByEmail(collaboratorEmail)
-      
-      console.log('👤 User profile found:', userProfile)
-      
-      if (!userProfile) {
-        setError(`User not found with email: ${collaboratorEmail.trim()}. Please make sure they have signed up on the platform.`)
-        alert(`User not found: ${collaboratorEmail.trim()}\n\nPlease make sure:\n1. The email is correct\n2. The user has signed up on the platform\n3. Try searching by name using the dropdown`)
-        return
-      }
+      console.log('🔍 Adding collaborator with email:', collaboratorEmail)
+
+      // Use API endpoint to add collaborator
+      const response = await fetch(`/api/projects/${selectedProject.id}/collaborators`, {
+        method: 'POST',
+        headers: {
+          'Content-Type': 'application/json',
+        },
+        body: JSON.stringify({
+          email: collaboratorEmail.trim(),
+          role: 'viewer'
+        })
+      })
 
-      const currentUser = getCurrentUser()
-      if (collaboratorEmail.toLowerCase().trim() === currentUser?.email.toLowerCase().trim()) {
-        alert("You cannot add yourself as a collaborator.")
-        return
-      }
+      const data = await response.json()
 
-      // Check if already a collaborator
-      const collaborators = await getProjectCollaborators(selectedProject.id)
-      if (collaborators.some(c => c.user_id === userProfile.id)) {
-        alert("This user is already a collaborator.")
+      if (!response.ok) {
+        setError(data.error || "Failed to add collaborator")
+        alert(data.error || "Failed to add collaborator. Please try again.")
         return
       }
 
-      console.log('✅ Adding collaborator:', userProfile.email)
-
-      // Add collaborator
-      await addProjectCollaborator(
-        selectedProject.id, 
-        userProfile.id, 
-        'viewer',
-        currentUser?.id
-      )
+      console.log('✅ Collaborator added successfully')
 
       setCollaboratorEmail("")
       setUserSearchResults([])
       setShowUserSearch(false)
-      alert(`✅ Successfully added ${userProfile.name || userProfile.email} as a collaborator!`)
+      alert(`✅ Successfully added ${data.collaborator.profile.name || data.collaborator.profile.email} as a collaborator!`)
 
+      // Reload projects to show new collaborator
       await loadProjects()
 
-      // Reload selected project to show new collaborator
-      const updatedProjects = await getProjects(currentUser!.id)
-      const updated = updatedProjects.find((p: any) => p.id === selectedProject.id)
-      if (updated) {
-        const collaborators = await getProjectCollaborators(updated.id)
-        const collaboratorEmails = await Promise.all(
-          collaborators.map(async (c) => {
-            const profile = await getProfileByEmail(c.user_id)
-            return profile?.email || ''
-          })
-        )
+      // Update selected project
+      const collaboratorsResponse = await fetch(`/api/projects/${selectedProject.id}/collaborators`)
+      const collaboratorsData = await collaboratorsResponse.json()
+      
+      if (collaboratorsResponse.ok) {
+        const collaboratorEmails = collaboratorsData.collaborators
+          .map((c: any) => c.profiles?.email)
+          .filter((email: string | undefined): email is string => Boolean(email))
+        
         setSelectedProject({
           ...selectedProject,
-          collaborators: collaboratorEmails.filter(e => e)
+          collaborators: collaboratorEmails
         })
       }
     } catch (err) {
@@ -324,26 +311,33 @@ export default function ProjectsPage() {
         return
       }
 
-      // Remove collaborator
-      await removeProjectCollaborator(selectedProject.id, userProfile.id)
+      // Use API endpoint to remove collaborator
+      const response = await fetch(`/api/projects/${selectedProject.id}/collaborators?userId=${userProfile.id}`, {
+        method: 'DELETE'
+      })
+
+      const data = await response.json()
+
+      if (!response.ok) {
+        alert(data.error || "Failed to remove collaborator")
+        return
+      }
 
+      // Reload projects
       await loadProjects()
 
       // Update selected project
-      const currentUser = getCurrentUser()
-      const updatedProjects = await getProjects(currentUser!.id)
-      const updated = updatedProjects.find((p: any) => p.id === selectedProject.id)
-      if (updated) {
-        const collaborators = await getProjectCollaborators(updated.id)
-        const collaboratorEmails = await Promise.all(
-          collaborators.map(async (c) => {
-            const profile = await getProfileByEmail(c.user_id)
-            return profile?.email || ''
-          })
-        )
+      const collaboratorsResponse = await fetch(`/api/projects/${selectedProject.id}/collaborators`)
+      const collaboratorsData = await collaboratorsResponse.json()
+      
+      if (collaboratorsResponse.ok) {
+        const collaboratorEmails = collaboratorsData.collaborators
+          .map((c: any) => c.profiles?.email)
+          .filter((email: string | undefined): email is string => Boolean(email))
+        
         setSelectedProject({
           ...selectedProject,
-          collaborators: collaboratorEmails.filter(e => e)
+          collaborators: collaboratorEmails
         })
       }
     } catch (err) {