using UnityEngine;
using System.Collections;
using System.IO;
using Unity.Collections;
using UnityEngine.Rendering;

/// <summary>
/// Sauvegarde deux vues personnalisées pour le PDF.
///
/// Bouton 1 → SaveView1()  → pdfview1.jpg  (remplace la vue scène principale)
/// Bouton 2 → SaveView2()  → pdfview2.jpg  (vue supplémentaire dans le PDF)
///
/// Si les fichiers existent lors de la génération PDF, PDFCreation les utilise
/// au lieu de faire une capture automatique.
///
/// Dossier : Application.persistentDataPath/PDFViews/
/// </summary>
public class PDFViewSaver : MonoBehaviour
{
    // ─── Constantes ──────────────────────────────────────────────────────────
    private const string FOLDER       = "PDFViews";
    private const int    CAPTURE_W    = 1280;
    private const int    CAPTURE_H    = 750;
    private const int    JPEG_QUALITY = 85;

    // ─── Chemin des fichiers (statique — accessible par PDFCreation) ─────────

    // Sous Windows : dossier fixe "F:/PDF CLIENTS/Views" ; sinon repli sur persistentDataPath/PDFViews.
    public static string BaseFolder =>
        (Application.platform == RuntimePlatform.WindowsPlayer ||
         Application.platform == RuntimePlatform.WindowsEditor)
        ? @"F:/PDF CLIENTS/Views"
        : Path.Combine(Application.persistentDataPath, FOLDER);

    public static string GetViewPath(int index) =>
        Path.Combine(BaseFolder, $"pdfview{index}.jpg");

    public static bool ViewExists(int index) => File.Exists(GetViewPath(index));

    // ─── Boutons ─────────────────────────────────────────────────────────────

    /// <summary>Bouton 1 — Sauvegarde la vue actuelle comme pdfview1.jpg</summary>
    public void SaveView1() => StartCoroutine(SaveViewCoroutine(1));

    /// <summary>Bouton 2 — Sauvegarde la vue actuelle comme pdfview2.jpg</summary>
    public void SaveView2() => StartCoroutine(SaveViewCoroutine(2));

    // ─── Interne ─────────────────────────────────────────────────────────────

    private RenderTexture _captureRT;

    private IEnumerator SaveViewCoroutine(int index)
    {
        WaitCircle.Setting(true, $"Sauvegarde vue PDF {index}...");

        bool wasHD = _G.HD;
        if (!wasHD) DASH.HDsetBTNcolor(true);

        yield return new WaitForSeconds(0.5f);

        Camera cam = Camera.main;
        if (cam == null)
        {
            Debug.LogError("[PDFViewSaver] Camera.main introuvable");
            WaitCircle.Setting(false, "");
            yield break;
        }

        // Capture dans une RenderTexture
        var rt        = new RenderTexture(CAPTURE_W, CAPTURE_H, 24);
        var savedRT   = cam.targetTexture;
        cam.targetTexture = rt;
        cam.Render();
        cam.targetTexture = savedRT;

        // Flip vertical (même convention que PDFCreation.CaptureToRenderTexture)
        _captureRT = new RenderTexture(CAPTURE_W, CAPTURE_H, 24);
        Graphics.Blit(rt, _captureRT, new Vector2(1f, -1f), new Vector2(0f, 1f));
        rt.Release();
        Destroy(rt);

        if (!wasHD) DASH.HDsetBTNcolor(false);

        // Lecture GPU asynchrone → sauvegarde
        AsyncGPUReadback.Request(_captureRT, 0, TextureFormat.RGBA32,
            req => OnReadbackDone(req, index));
    }

    private void OnReadbackDone(AsyncGPUReadbackRequest req, int index)
    {
        var format  = _captureRT.graphicsFormat;
        uint width  = (uint)_captureRT.width;
        uint height = (uint)_captureRT.height;
        _captureRT.Release();
        Destroy(_captureRT);
        _captureRT = null;

        if (req.hasError)
        {
            Debug.LogError($"[PDFViewSaver] Erreur GPU readback (vue {index})");
            WaitCircle.Setting(false, "");
            return;
        }

        // Second flip (identique à PDFCreation.RequestFlip)
        NativeArray<byte> raw  = req.GetData<byte>();
        int w = (int)width;
        int h = (int)height;
        var tex       = new Texture2D(w, h, TextureFormat.RGBA32, false);
        var processed = tex.GetRawTextureData<byte>();

        for (int i = 0; i < raw.Length; i += 4)
        {
            int pixel      = i / 4;
            int x          = pixel % w;
            int y          = pixel / w;
            int flippedIdx = (x + (h - 1 - y) * w) * 4;
            processed[i]     = raw[flippedIdx];
            processed[i + 1] = raw[flippedIdx + 1];
            processed[i + 2] = raw[flippedIdx + 2];
            processed[i + 3] = raw[flippedIdx + 3];
        }

        // Encoder en JPEG
        byte[] jpg = ImageConversion.EncodeArrayToJPG(
            processed.ToArray(), format, width, height, 0, JPEG_QUALITY);

        // Créer le dossier et sauvegarder
        string dir  = BaseFolder;
        Directory.CreateDirectory(dir);
        string path = GetViewPath(index);
        File.WriteAllBytes(path, jpg);

        Destroy(tex);

        Debug.Log($"✅ [PDFViewSaver] Vue {index} sauvegardée ({jpg.Length / 1024} KB)\n→ {path}");
        WaitCircle.Setting(false, "");
    }
}