feat: improved template-based system prompt

notetaker/Models/Settings.swift

@@ -6,7 +6,23 @@ struct Settings: Codable {
     var userBlurb: String
     var systemPrompt: String
     
-    static let defaultSystemPrompt = "Generate concise meeting notes from the transcript and any additional notes provided. Focus on key points, action items, and decisions made."
+    static let defaultSystemPrompt: String = {
+        guard let url = Bundle.main.url(forResource: "DefaultSystemPrompt", withExtension: "txt"),
+              let content = try? String(contentsOf: url) else {
+            assertionFailure("DefaultSystemPrompt.txt missing from bundle")
+            return ""
+        }
+        return content
+    }()
+    
+    // Required variables for the template
+    static let requiredVariables: Set<String> = [
+        "meeting_title",
+        "meeting_date", 
+        "transcript",
+        "user_blurb",
+        "user_notes"
+    ]
     
     init(deepgramKey: String = "",
          openAIKey: String = "",
@@ -17,4 +33,40 @@ struct Settings: Codable {
         self.userBlurb = userBlurb
         self.systemPrompt = systemPrompt
     }
+    
+    // MARK: - Template Methods
+    
+    /// Extracts all template variables from a system prompt string
+    static func extractTemplateVariables(from template: String) -> Set<String> {
+        let pattern = #"\{\{(\w+)\}\}"#
+        let regex = try! NSRegularExpression(pattern: pattern, options: [])
+        let matches = regex.matches(in: template, options: [], range: NSRange(location: 0, length: template.count))
+        
+        var variables: Set<String> = []
+        for match in matches {
+            if let range = Range(match.range(at: 1), in: template) {
+                variables.insert(String(template[range]))
+            }
+        }
+        return variables
+    }
+    
+    /// Validates that all required variables are present in the system prompt
+    func validateSystemPrompt() -> (isValid: Bool, missingVariables: Set<String>) {
+        let presentVariables = Settings.extractTemplateVariables(from: systemPrompt)
+        let missingVariables = Settings.requiredVariables.subtracting(presentVariables)
+        return (isValid: missingVariables.isEmpty, missingVariables: missingVariables)
+    }
+    
+    /// Replaces template variables in the system prompt with actual values
+    static func processTemplate(_ template: String, with variables: [String: String]) -> String {
+        var result = template
+        
+        for (key, value) in variables {
+            let placeholder = "{{\(key)}}"
+            result = result.replacingOccurrences(of: placeholder, with: value)
+        }
+        
+        return result
+    }
 }