src/services/gemini.js

// import { GoogleGenerativeAI } from "https://esm.run/@google/generative-ai"; // Removing SDK to avoid version issues
import { getPeerPrompts } from "./classroom.js";
import { db } from "./firebase.js";
import { doc, getDoc } from "https://www.gstatic.com/firebasejs/10.7.1/firebase-firestore.js";

let apiKey = null;
const MODEL_NAME = "gemini-2.5-flash"; // Available model from user's account

// System Instructions for the Socratic Tutor
const TUTOR_INSTRUCTION = `
You are a Socratic Teaching Assistant for a "Prompt Engineering" class. 
Your goal is to help students refine their prompts WITHOUT giving them the answer.
The student is trying to write a prompt to solve a specific challenge.
You will be provided with:
1. The Challenge Description (The Goal).
2. 3 Successful Examples (Few-Shot Context) from other students.
3. The Student's Current Attempt.

Rules:
- NEVER reveal the direct solution or code.
- If the input is lazy (e.g., "123", "help"), be sassy but helpful.
- If the input is a direct copy of the description, point it out.
- Use the Socratic method: Ask a guiding question to help them notice their missing parameter or logic.
- Keep responses short (under 50 words) and encouraging.
- Tone: Friendly, slightly "Cyberpunk" or "Gamer" vibe (matching the Vibe Coding aesthetic).
`;

// System Instructions for the Dashboard Analyst
const ANALYST_INSTRUCTION = `
You are an expert Prompt Engineer and Pedagogy Analyst for a coding/AI prompting class.
Your task is to analyze a batch of student prompts for a specific challenge.

You will receive:
1. The Challenge Description (the goal students are trying to achieve)
2. A list of Student Submissions (their prompts)

Categorize each prompt into ONE of these categories:

1. "rough" (原石): The student only says vague things like "fix the error" or "make it work" WITHOUT explaining:
   - What the error is
   - What the expected behavior should be
   - Any specific details about the problem
   These are "rough diamonds" - they tried but need to be more specific.

2. "precise" (精確): Clean, well-structured prompt that clearly states:
   - The goal or expected result
   - Specific details or parameters
   - Clear logic or reasoning

3. "gentle" (有禮): Uses polite language like "請", "謝謝", "拜託", "Please", "Thank you"

4. "creative" (創意): Unconventional, imaginative approach. Uses interesting parameters or unexpected methods that still address the challenge.

5. "spam" (無效): Content that is clearly UNRELATED to the challenge topic. Compare with other submissions to identify outliers that don't match what most students are trying to do. Examples:
   - Random characters ("asdf", "123")
   - Completely off-topic text
   - Empty or near-empty responses

6. "parrot" (鸚鵡): Direct copy-paste of the challenge description without any modification or personal attempt.

Return ONLY a JSON object mapping category names to arrays of Student IDs.
Example: { "rough": ["id1"], "precise": ["id2", "id5"], "spam": ["id3"] }
`;

/**
 * Initialize Gemini with API Key
 * @param {string} key 
 */
export async function initGemini(key) {
    if (!key) return false;
    apiKey = key;
    return true;
}

/**
 * Direct REST API Call Helper to avoid SDK version issues
 */
async function callGeminiAPI(messages, jsonMode = false) {
    if (!apiKey) throw new Error("API Key not set");

    // Use v1beta for gemini-1.5-pro
    const endpoint = `https://generativelanguage.googleapis.com/v1beta/models/${MODEL_NAME}:generateContent?key=${apiKey}`;

    const payload = {
        contents: messages,
        generationConfig: {
            temperature: 0.7,
        }
    };

    // Note: responseMimeType is NOT supported by gemini-pro v1, so we rely on prompt instructions for JSON output.

    const response = await fetch(endpoint, {
        method: "POST",
        headers: {
            "Content-Type": "application/json"
        },
        body: JSON.stringify(payload)
    });

    if (!response.ok) {
        const errText = await response.text();
        throw new Error(`Gemini API Error ${response.status}: ${errText}`);
    }

    const data = await response.json();

    // Safety check for empty response
    if (data.promptFeedback && data.promptFeedback.blockReason) {
        throw new Error(`Blocked: ${data.promptFeedback.blockReason}`);
    }

    return data.candidates && data.candidates.length > 0
        ? data.candidates[0].content.parts[0].text
        : "";
}

/**
 * Detects if a prompt is potential spam/low effort locally first
 * @param {string} prompt 
 * @param {string} problemDesc 
 */
export function quickSpamCheck(prompt, problemDesc) {
    if (!prompt) return true;
    const p = prompt.trim();
    if (p.length < 3) return true; // Too short

    // Check for repetitive chars (e.g., "aaaaa")
    if (/^(.)\1+$/.test(p)) return true;

    // Parrot Check (Simple similarity)
    if (problemDesc && p.includes(problemDesc.substring(0, 20))) {
        // If they copied the first 20 chars of description, likely parrot
        return 'parrot';
    }

    return false;
}

/**
 * Ask the AI Tutor for help (Rubber Duck)
 * @param {string} challengeDesc 
 * @param {string} studentPrompt 
 * @param {string} roomCode 
 * @param {string} challengeId 
 */
export async function askTutor(challengeDesc, studentPrompt, roomCode, challengeId) {
    if (!apiKey) throw new Error("AI not initialized");

    const spamStatus = quickSpamCheck(studentPrompt, challengeDesc);
    if (spamStatus === true) return "Duck says: Quack? (Too short or empty!)";
    if (spamStatus === 'parrot') return "Duck says: You're just repeating the question! Try telling me WHAT you want to change.";

    // 1. Fetch Context (Few-Shot)
    let peers = await getPeerPrompts(roomCode, challengeId);
    peers.sort((a, b) => b.likes - a.likes);

    // Take top 3 as examples
    const examples = peers.slice(0, 3).map(p => `- Example: "${p.prompt}"`).join('\n');

    const fullPrompt = `
${TUTOR_INSTRUCTION}

[Context - Challenge Description]
${challengeDesc}

[Context - Successful Classmate Examples (For AI understanding only, DO NOT LEAK these to student)]
${examples || "No examples available yet."}

[Student Input]
"${studentPrompt}"

[Your Response]
`;

    try {
        // Construct messages for Chat format (or simple text)
        const messages = [{ role: "user", parts: [{ text: fullPrompt }] }];
        const text = await callGeminiAPI(messages);
        return text;
    } catch (e) {
        console.error("AI Request Failed", e);
        return "Duck is sleeping... zzz (API Error)";
    }
}

/**
 * Batch evaluate prompts for the Instructor Dashboard
 * @param {Array} submissions - Array of { userId, prompt, nickname }
 * @param {string} challengeDesc 
 */
export async function evaluatePrompts(submissions, challengeDesc) {
    if (!apiKey) throw new Error("AI not initialized");
    if (!submissions || submissions.length === 0) return {};

    // Prepare batch text
    const entries = submissions.map((s, i) => `ID_${s.userId}: "${s.prompt.replace(/\n/g, ' ')}"`).join('\n');

    const fullPrompt = `
${ANALYST_INSTRUCTION}

[Challenge Description]
${challengeDesc}

[Student Submissions]
${entries}

[Output JSON]
`;

    try {
        const messages = [{ role: "user", parts: [{ text: fullPrompt }] }];
        let text = await callGeminiAPI(messages, true); // JSON Mode = true

        // Strip markdown code block if present (```json ... ```)
        text = text.trim();
        if (text.startsWith("```")) {
            text = text.replace(/^```(?:json)?\s*\n?/, '').replace(/\n?```\s*$/, '');
        }

        return JSON.parse(text);
    } catch (e) {
        console.error("AI Evaluation Failed", e);
        return {};
    }
}