"""argparse for inference.py."""

import argparse


def str_to_bool(s):
    if isinstance(s, bool):
        return s
    if isinstance(s, str):
        return s.lower() in ("true", "1", "yes")
    if isinstance(s, (int, float)):
        return bool(s)
    raise argparse.ArgumentTypeError(f"Expected true/false, got {s!r}")


_DEFAULT_PROMPT = (
    "Documentary-style imagery: a lively little dog stands still on a lush green lawn, "
    "filling the entire frame. The dog has brownish-yellow fur, with both ears perked up, "
    "and an expression that is focused and cheerful."
)


def build_parser() -> argparse.ArgumentParser:
    p = argparse.ArgumentParser(description="FLUX2 Foveated Image Generation")

    # Model
    p.add_argument("--model_id", type=str, default="black-forest-labs/FLUX.2-klein-base-4B",
                   help="HuggingFace model ID for FLUX2")
    p.add_argument("--lora_checkpoint", default=None, type=str, help="Path to LoRA .safetensors")
    p.add_argument("--dit_checkpoint", default=None, type=str, help="Path to full DiT checkpoint")

    # Generation
    p.add_argument("--height", type=int, default=1024)
    p.add_argument("--width", type=int, default=1024)
    p.add_argument("--num_inference_steps", type=int, default=50)
    p.add_argument("--guidance_scale", type=float, default=4.0)
    p.add_argument("--prompt", type=str, default=_DEFAULT_PROMPT)
    p.add_argument("--seed", type=int, default=0)
    p.add_argument("--decode_mode", type=str, default="direct", choices=["direct", "merge"])
    p.add_argument("--prediction_type", type=str, default="clean", choices=["clean", "flow", "refiner"])
    p.add_argument("--soft_foveation_blend", type=str_to_bool, default=False,
                   help="Use a Gaussian-falloff foveation mask boundary in merge decode")
    p.add_argument("--lr_downsample_factor", type=int, default=2, choices=[2, 4],
                   help="Spatial downsampling factor for LR periphery (2 = 4x fewer LR tokens, 4 = 16x)")

    # Output
    p.add_argument("--output_dir", type=str, default="./outputs/flux2_foveated")

    # Experiment selection
    p.add_argument("--experiment", type=str, default="ours",
                   choices=[
                       "high_res", "naive_mixed_res", "ours",
                       "circular_traj", "vary_radius",
                       "runtime", "foveation_trajectory_grid",
                       "user_study",
                   ])

    # Full / distributed eval
    p.add_argument("--full_eval", action="store_true", default=False)
    p.add_argument("--subset_idx", type=int, default=0)
    p.add_argument("--num_subsets", type=int, default=1)
    p.add_argument("--full_eval_mask", type=str, default="square",
                   choices=["square", "checkerboard", "circular"])
    p.add_argument("--prompt_dataset_path", type=str, help="Path to CSV with a 'prompt' column")
    p.add_argument("--num_prompts", type=int, default=None)

    # Foveation trajectory grid
    p.add_argument("--num_cols", type=int, default=4)
    p.add_argument("--foveation_trajectory_type", type=str, default="circular",
                   choices=["radius", "circular", "random_circular", "polygons",
                            "multi_circle", "grid", "spiral"])
    p.add_argument("--grid_rows", type=int, default=3)
    p.add_argument("--grid_cols", type=int, default=3)
    p.add_argument("--outline_width_frac", type=float, default=0.005)
    p.add_argument("--outline_color", type=str, default="255,0,0")
    p.add_argument("--foveation_outline", type=str_to_bool, default=False)
    p.add_argument("--prompt_ids", type=int, nargs="+", default=None,
                   help="Explicit CSV row indices for foveation_trajectory_grid")

    # Circular / vary_radius experiment knobs
    p.add_argument("--num_frames", type=int, default=100)
    p.add_argument("--orbit_radius", type=float, default=0.25)
    p.add_argument("--mask_radius", type=float, default=0.30,
                   help="Foveation radius (circular) or side ratio (square)")
    p.add_argument("--mask_shape", type=str, default="circular",
                   choices=["circular", "square"])

    return p