const OLLAMA_API_URL = process.env.OLLAMA_API_URL;
const OLLAMA_API_KEY = process.env.OLLAMA_API_KEY;

async function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

async function callOllama(prompt, model = "gemma3:4b", retries = 3) {
  let attempt = 0;
  while (attempt < retries) {
    try {
      const response = await fetch(OLLAMA_API_URL, {
        method: "POST",
        headers: {
          "Authorization": `Bearer ${OLLAMA_API_KEY}`,
          "Content-Type": "application/json",
        },
        body: JSON.stringify({
          model,
          messages: [{ role: "user", content: prompt }],
        }),
      });

      if (!response.ok) {
        throw new Error(`Ollama API request failed: ${response.status} ${response.statusText}`);
      }

      const data = await response.json();
      const text = data.choices?.[0]?.message?.content;
      if (!text) throw new Error("No response from Ollama");
      return text;

    } catch (err) {
      attempt++;
      console.warn(`⚠️ Ollama call failed (attempt ${attempt}/${retries}): ${err.message}`);
      if (attempt >= retries) throw err;
      await sleep(1000 * attempt); // exponential backoff
    }
  }
}

/**
 * Three-pass dungeon generation with full resiliency and JSON retry
 */
export async function generateDungeon() {
  console.log("🏗️  Starting dungeon generation...");

  let draft, refined, jsonText;

  // Draft Pass
  try {
    console.log("📝 Draft pass...");
    const draftPrompt = `
Generate a Dungeons & Dragons one-page dungeon concept.
Include a title, flavor text, hooks, rumors, rooms, encounters, treasure, and NPCs.
Output in readable text (not JSON). Focus on interesting ideas and adventure hooks.
`;
    draft = await callOllama(draftPrompt);
    console.log("✅ Draft pass complete.");
  } catch (err) {
    console.error("❌ Draft pass failed:", err);
    throw new Error("Dungeon generation failed at draft step");
  }

  // Refine Pass
  try {
    console.log("🔧 Refine pass...");
    const refinePrompt = `
Here is a draft dungeon description:

${draft}

Please carefully proofread this dungeon and improve it for professionalism and clarity:
- Fix any spelling, grammar, or phrasing issues
- Flesh out any vague or unclear descriptions
- Add richer flavor text to rooms, encounters, and NPCs
- Ensure all hooks, rumors, and treasures are compelling and well-explained
- Make the dungeon read as a polished, professional one-page adventure

Keep the output as readable text format, not JSON.
`;
    refined = await callOllama(refinePrompt);
    console.log("✅ Refine pass complete.");
  } catch (err) {
    console.warn("⚠️ Refine pass failed, using draft as fallback:", err.message);
    refined = draft;
  }

  // JSON Pass with retries
  const jsonPrompt = `
Convert the following improved dungeon description into strictly valid JSON.
Use the following fields:
- title
- flavor
- map (just a placeholder string like "map.png")
- hooks (array of strings)
- rumors (array of strings)
- rooms (array of objects with "name" and "description")
- encounters (array of objects with "name" and "details")
- treasure (array of strings)
- npcs (array of objects with "name" and "trait")
Do not include any commentary, only output valid JSON.

Dungeon description:
${refined}
`;

  const maxJsonRetries = 3;
  for (let attempt = 1; attempt <= maxJsonRetries; attempt++) {
    try {
      console.log(`📦 JSON pass (attempt ${attempt}/${maxJsonRetries})...`);
      jsonText = await callOllama(jsonPrompt);
      const cleaned = jsonText.replace(/```json|```/g, "").trim();
      const result = JSON.parse(cleaned);
      console.log("🎉 Dungeon generation complete!");
      return result;
    } catch (err) {
      console.warn(`⚠️ JSON parse failed (attempt ${attempt}/${maxJsonRetries}): ${err.message}`);
      if (attempt === maxJsonRetries) {
        console.error("❌ JSON pass ultimately failed. Raw output:", jsonText);
        throw new Error("Dungeon generation failed at JSON step");
      }
      await sleep(1000 * attempt);
    }
  }
}