# VGGT with custom trained DPT/SDT checkpoint (LoRA)
import os
import sys
from typing import *
from pathlib import Path

import click
import torch
import torch.nn.functional as F
import torchvision.transforms as T
import torchvision.transforms.functional as TF

from moge.test.baseline import MGEBaselineInterface


class Baseline(MGEBaselineInterface):
    def __init__(self, repo_path: str, checkpoint: str, decoder: str, lora_rank: int, lora_alpha: int, num_tokens: int, device: Union[torch.device, str]):
        # Create from repo
        repo_path = os.path.abspath(repo_path)
        training_path = os.path.join(repo_path, 'training')
        if training_path not in sys.path:
            sys.path.insert(0, training_path)
        if repo_path not in sys.path:
            sys.path.insert(0, repo_path)
        if not Path(repo_path).exists():
            raise FileNotFoundError(f'Cannot find the VGGT repository at {repo_path}.')

        device = torch.device(device)

        # Build model based on decoder type
        if decoder == 'dpt':
            from vggt.models.vggt import VGGT
            model = VGGT(
                enable_camera=True,
                enable_depth=True,
                enable_point=False,
                enable_track=False,
            )
        elif decoder == 'sdt':
            from vggt.models.vggt_sdt import VGGT_SDT
            model = VGGT_SDT(
                enable_camera=True,
                enable_depth=True,
                enable_point=False,
                enable_track=False,
            )
        else:
            raise ValueError(f"Unknown decoder: {decoder}")

        # Apply LoRA
        from lora import apply_lora
        model = apply_lora(model, rank=lora_rank, alpha=lora_alpha)
        print(f"Applied LoRA (rank={lora_rank}, alpha={lora_alpha})")

        # Load checkpoint
        if not os.path.exists(checkpoint):
            raise FileNotFoundError(f'Cannot find checkpoint at {checkpoint}')

        ckpt = torch.load(checkpoint, map_location='cpu')
        if 'model' in ckpt:
            state_dict = ckpt['model']
        else:
            state_dict = ckpt

        # Remove 'module.' prefix if present
        state_dict = {k.replace('module.', ''): v for k, v in state_dict.items()}

        missing, unexpected = model.load_state_dict(state_dict, strict=False)
        print(f"Loaded checkpoint from {checkpoint}")
        if missing:
            print(f"Missing keys: {len(missing)}")
        if unexpected:
            print(f"Unexpected keys: {len(unexpected)}")

        model.to(device).eval()
        self.model = model
        self.num_tokens = num_tokens
        self.device = device

    @click.command()
    @click.option('--repo', 'repo_path', type=click.Path(), default='/home/ywan0794/vggt', help='Path to the VGGT repository.')
    @click.option('--checkpoint', type=click.Path(), required=True, help='Path to trained checkpoint.')
    @click.option('--decoder', type=click.Choice(['dpt', 'sdt']), default='dpt', help='Decoder type.')
    @click.option('--lora_rank', type=int, default=8, help='LoRA rank.')
    @click.option('--lora_alpha', type=int, default=16, help='LoRA alpha.')
    @click.option('--num_tokens', type=int, default=None, help='Number of tokens to use for the input image.')
    @click.option('--device', type=str, default='cuda', help='Device to use for inference.')
    @staticmethod
    def load(repo_path: str, checkpoint: str, decoder: str, lora_rank: int, lora_alpha: int, num_tokens: int, device: torch.device = 'cuda'):
        return Baseline(repo_path, checkpoint, decoder, lora_rank, lora_alpha, num_tokens, device)

    @torch.inference_mode()
    def infer(self, image: torch.Tensor, intrinsics: Optional[torch.Tensor] = None) -> Dict[str, torch.Tensor]:
        original_height, original_width = image.shape[-2:]

        if image.ndim == 3:
            image = image.unsqueeze(0)
            omit_batch_dim = True
        else:
            omit_batch_dim = False

        if self.num_tokens is None:
            resize_factor = 518 / min(original_height, original_width)
            expected_width = round(original_width * resize_factor / 14) * 14
            expected_height = round(original_height * resize_factor / 14) * 14
        else:
            aspect_ratio = original_width / original_height
            tokens_rows = round((self.num_tokens * aspect_ratio) ** 0.5)
            tokens_cols = round((self.num_tokens / aspect_ratio) ** 0.5)
            expected_width = tokens_cols * 14
            expected_height = tokens_rows * 14

        image = TF.resize(image, (expected_height, expected_width), interpolation=T.InterpolationMode.BICUBIC, antialias=True)

        # VGGT expects [0, 1] range, not ImageNet normalized
        image = image.to(self.device)

        # VGGT expects sequence of images: [B, S, 3, H, W]
        rgb_seq = image.unsqueeze(1).repeat(1, 2, 1, 1, 1)

        # Forward pass
        with torch.cuda.amp.autocast(dtype=torch.bfloat16):
            output = self.model(images=rgb_seq)

        # Extract depth from prediction
        # pred["depth"] shape: [B, S, H, W, 1]
        depth = output["depth"][0, 0, :, :, 0]

        # Convert depth to disparity
        disparity = 1.0 / (depth + 1e-6)

        disparity = F.interpolate(disparity[None, None], size=(original_height, original_width), mode='bilinear', align_corners=False, antialias=False)[0, 0]

        if omit_batch_dim:
            pass  # already squeezed

        return {
            'disparity_affine_invariant': disparity
        }