// xAI Grok Imagine — text-to-image + single/multi image editing
// Docs:
//   https://docs.x.ai/developers/model-capabilities/images/generation
//   https://docs.x.ai/developers/model-capabilities/images/editing
//   https://docs.x.ai/developers/model-capabilities/images/multi-image-editing
import { sizeToAspectRatio } from "./_base.js";
import { PROVIDER_MEDIA } from "../../providers/index.js";

const IMG_CFG = PROVIDER_MEDIA["xai"]?.imageConfig || {};
const GENERATIONS_URL = IMG_CFG.baseUrl || "https://api.x.ai/v1/images/generations";
const EDITS_URL = IMG_CFG.editsUrl || "https://api.x.ai/v1/images/edits";

const ASPECT_RATIOS = new Set([
  "auto",
  "1:1",
  "16:9",
  "9:16",
  "4:3",
  "3:2",
  "2:3",
  "9:19.5",
  "20:9",
]);

function hasEditInput(body) {
  if (!body || typeof body !== "object") return false;
  if (body.image) return true;
  return Array.isArray(body.images) && body.images.some(Boolean);
}

/** Normalize client image input → xAI image ref object */
function toXaiImageRef(input) {
  if (!input) return null;

  if (typeof input === "object") {
    // Already xAI-shaped or partial
    if (input.file_id) {
      return {
        type: input.type || "image_url",
        file_id: input.file_id,
        ...(input.url ? { url: input.url } : {}),
      };
    }
    if (input.url) {
      return { type: input.type || "image_url", url: input.url };
    }
    return null;
  }

  if (typeof input !== "string") return null;
  const trimmed = input.trim();
  if (!trimmed) return null;

  // Public URL or data URI
  if (/^https?:\/\//i.test(trimmed) || /^data:image\//i.test(trimmed)) {
    return { type: "image_url", url: trimmed };
  }

  // Raw base64 → data URI
  return { type: "image_url", url: `data:image/png;base64,${trimmed}` };
}

function collectImageRefs(body) {
  const refs = [];
  if (Array.isArray(body.images)) {
    for (const item of body.images) {
      const ref = toXaiImageRef(item);
      if (ref) refs.push(ref);
    }
  }
  if (body.image) {
    const ref = toXaiImageRef(body.image);
    if (ref) refs.push(ref);
  }
  // xAI multi-edit supports up to 3 source images
  return refs.slice(0, 3);
}

function resolveAspectRatio(body) {
  if (typeof body.aspect_ratio === "string" && body.aspect_ratio.trim()) {
    const ratio = body.aspect_ratio.trim();
    if (ASPECT_RATIOS.has(ratio)) return ratio;
    // Pass through unknown ratio strings (upstream will validate)
    return ratio;
  }
  // OpenAI-style size → aspect ratio (skip auto)
  if (body.size && body.size !== "auto") {
    return sizeToAspectRatio(body.size);
  }
  return undefined;
}

function resolveResolution(body) {
  if (typeof body.resolution !== "string") return undefined;
  const value = body.resolution.trim().toLowerCase();
  if (!value || value === "auto") return undefined;
  return value; // "1k" | "2k"
}

export default {
  buildUrl: (_model, _credentials, body) => (hasEditInput(body) ? EDITS_URL : GENERATIONS_URL),

  buildHeaders: (creds) => {
    const headers = { "Content-Type": "application/json", ...(IMG_CFG.headers || {}) };
    const key = creds?.apiKey || creds?.accessToken;
    if (key) headers["Authorization"] = `Bearer ${key}`;
    return headers;
  },

  buildBody: (model, body) => {
    const req = {
      model,
      prompt: body.prompt,
    };

    if (body.n != null) req.n = body.n;
    if (body.response_format) req.response_format = body.response_format;

    const aspectRatio = resolveAspectRatio(body);
    if (aspectRatio) req.aspect_ratio = aspectRatio;

    const resolution = resolveResolution(body);
    if (resolution) req.resolution = resolution;

    const refs = collectImageRefs(body);
    if (refs.length === 1) {
      req.image = refs[0];
    } else if (refs.length > 1) {
      req.images = refs;
    }

    return req;
  },

  // xAI already returns OpenAI-compatible { created, data: [{ url | b64_json }] }
  normalize: (responseBody) => responseBody,
};