src/gemini_generator.py

import os
import random
from google import genai
from google.genai import types

class GeminiScriptGenerator:
    def __init__(self):
        # API Key from Environment
        self.api_key = os.environ.get("GEMINI_API_KEY")
        if not self.api_key:
            print("❌ GEMINI_API_KEY not found in environment variables.", flush=True)
            self.client = None
            return

        try:
            self.client = genai.Client(api_key=self.api_key)
            print("✅ Gemini Client Initialized (google-genai SDK)", flush=True)
        except Exception as e:
            print(f"❌ Failed to initialize Gemini Client: {e}", flush=True)
            self.client = None

    def generate_script(self):
        if not self.client:
            return None, "Error_No_Gemini_Client"

        # Topic Rotation
        topics = [
            "Dark Psychology: How People Control You Without Force",
            "The Psychology of Manipulation in Daily Life",
            "How Gaslighting Makes You Doubt Yourself",
            "Why Silent Treatment Is Psychological Control",
            "How Narcissists Use Praise and Punishment",
            "The Dark Psychology of Guilt Tripping",
            "How People Use Fear of Loss Against You",
            "The Psychology of Love Bombing",
            "How Toxic People Test Your Boundaries",
            "The Psychology of Emotional Blackmail",
            "Why Some People Always Play the Victim",
            "How Triangulation Creates Jealousy and Control",
            "The Psychology of Push-Pull Behavior",
            "How People Use Confusion to Control You",
            "Why Over-Explaining Makes You Easier to Control",
            "The Dark Psychology of Intermittent Reward",
            "How Fake Nice People Manipulate Trust",
            "The Psychology of Power in Relationships",
            "How Manipulators Make You Feel Responsible for Their Emotions",
            "Why Walking Away Breaks Manipulation",
            "Why Your 20s Decide Your Whole Life",
            "How to Build Discipline Without Motivation",
            "Why Most Students Waste Time Without Realizing It",
            "Dark Psychology Tricks People Use in Daily Life",
            "How to Read People's Intentions Through Small Behaviors",
            "Why Confidence Makes People Treat You Differently",
            "The Psychology of Focus in a Distracted World",
            "Why Some People Become Addicted to Comfort",
            "How to Stop Overthinking and Take Control",
            "The Hidden Psychology of Respect and Status",
            "Why Consistency Beats Talent Every Time",
            "How to Train Your Mind for Success"
        ]
        topic = random.choice(topics)
        print(f"🧠 Gemini Generating Script on Topic: {topic}...", flush=True)

        system_prompt = (
            "You are an expert YouTube script writer for an English self-improvement and psychology channel. "
            "Your writing feels intense, cinematic, smart, addictive, calm, sharp, and psychologically observant. "
            "You write like a smart creator talking directly to viewers, not like a teacher reading notes."
        )

        user_prompt = (
            f"TOPIC: {topic}\n\n"
            "Write a HIGH RETENTION YouTube script in natural English only.\n"
            "Requirements:\n"
            "1. VIDEO LENGTH TARGET: 8 minutes.\n"
            "2. Strong hook in the first 15 seconds. Do NOT say hello, welcome, or intro lines.\n"
            "3. Build curiosity fast using tension, questions, twists, and sharp observations.\n"
            "4. Explain ideas using realistic real-life examples: students, career, relationships, discipline, social behavior, phone addiction, comfort zone, status, confidence.\n"
            "5. Every 20-30 seconds must contain a hook, question, twist, or insight.\n"
            "6. Tone: calm, sharp, psychologically intense. Avoid cringe motivation lines and robotic explanations.\n"
            "7. Use short punchy lines. Keep pacing tight. No filler. Do NOT repeat points.\n"
            "8. Occasionally use dramatic pauses naturally, like: 'And this is where the game begins...', 'Most people never notice this...', 'That is not a coincidence.'\n"
            "9. End with a strong conclusion or uncomfortable question that makes the viewer think.\n"
            "10. After the spoken script, add title suggestions and thumbnail text ideas only.\n"
            "11. Do not add SEO keywords inside the script or after the script.\n"
            "12. Format clearly with these labels only: SCRIPT:, TITLE SUGGESTIONS:, THUMBNAIL TEXT IDEAS:.\n"
            "12. The SCRIPT section must be clean for TTS reading and should be around 1100-1300 words."
        )

        # List of models to try in order (Fastest -> Fallback)
        # These IDs are from ListModels output for this API key
        models_to_try = [
            "gemini-2.5-flash-preview-09-2025",  # Latest 2.5 Flash
            "gemini-flash-latest",                # Stable Flash alias
            "gemini-pro-latest",                  # Pro alias
        ]

        for model_id in models_to_try:
            try:
                print(f"🧠 Trying Gemini Model: {model_id}...", flush=True)

                # Flash Config (No Thinking Mode to save tokens/time)
                generate_content_config = types.GenerateContentConfig(
                    temperature=1.0, # High Creativity
                    max_output_tokens=4096, 
                    safety_settings=[
                        types.SafetySetting(category="HARM_CATEGORY_HARASSMENT", threshold="BLOCK_NONE"),
                        types.SafetySetting(category="HARM_CATEGORY_HATE_SPEECH", threshold="BLOCK_NONE"),
                        types.SafetySetting(category="HARM_CATEGORY_SEXUALLY_EXPLICIT", threshold="BLOCK_NONE"),
                        types.SafetySetting(category="HARM_CATEGORY_DANGEROUS_CONTENT", threshold="BLOCK_NONE"),
                        types.SafetySetting(category="HARM_CATEGORY_CIVIC_INTEGRITY", threshold="BLOCK_NONE"),
                    ],
                )
                
                contents = [
                    types.Content(
                        role="user",
                        parts=[
                            types.Part.from_text(text=f"{system_prompt}\n\n{user_prompt}"),
                        ],
                    ),
                ]

                # Collect full response
                full_text = ""
                for chunk in self.client.models.generate_content_stream(
                    model=model_id,
                    contents=contents,
                    config=generate_content_config,
                ):
                    if chunk.text:
                        full_text += chunk.text
                
                print(f"\n✅ Gemini Generation Complete ({model_id})!", flush=True)
                
                script_content = full_text.strip()
                
                # Validation
                if len(script_content) < 500:
                    print(f"⚠️ Generated script too short ({len(script_content)} chars)!", flush=True)
                    continue # Try next model
                
                # Log Full Script
                print(f"\n📜 FULL GEMINI SCRIPT ({len(script_content)} chars):\n" + "="*50 + f"\n{script_content}\n" + "="*50 + "\n", flush=True)

                return script_content, topic

            except Exception as e:
                print(f"⚠️ Model {model_id} failed: {e}", flush=True)
                continue # Try next model
        
        return None, "All_Gemini_Models_Failed"

if __name__ == "__main__":
    # Test
    gen = GeminiScriptGenerator()
    script, topic = gen.generate_script()
    print(f"Topic: {topic}")