#[cfg(feature = "mkl")]
extern crate intel_mkl_src;

#[cfg(feature = "accelerate")]
extern crate accelerate_src;

use anyhow::{Error as E, Result};
use clap::Parser;

use candle::{DType, Device, Tensor};
use candle_nn::VarBuilder;
use candle_transformers::{generation::LogitsProcessor, models::moondream};
use tokenizers::Tokenizer;

struct TextGeneration {
    model: moondream::Model,
    device: Device,
    tokenizer: Tokenizer,
    logits_processor: LogitsProcessor,
    repeat_penalty: f32,
    repeat_last_n: usize,
    verbose_prompt: bool,
}

impl TextGeneration {
    #[allow(clippy::too_many_arguments)]
    fn new(
        model: moondream::Model,
        tokenizer: Tokenizer,
        seed: u64,
        temp: Option<f64>,
        top_p: Option<f64>,
        repeat_penalty: f32,
        repeat_last_n: usize,
        verbose_prompt: bool,
        device: &Device,
    ) -> Self {
        let logits_processor = LogitsProcessor::new(seed, temp, top_p);
        Self {
            model,
            tokenizer,
            logits_processor,
            repeat_penalty,
            repeat_last_n,
            verbose_prompt,
            device: device.clone(),
        }
    }

    fn run(&mut self, prompt: &str, image_embeds: &Tensor, sample_len: usize) -> Result<()> {
        use std::io::Write;
        println!("starting the inference loop");
        let tokens = self.tokenizer.encode(prompt, true).map_err(E::msg)?;
        if tokens.is_empty() {
            anyhow::bail!("Empty prompts are not supported in the Moondream model.")
        }
        if self.verbose_prompt {
            for (token, id) in tokens.get_tokens().iter().zip(tokens.get_ids().iter()) {
                let token = token.replace('▁', " ").replace("<0x0A>", "\n");
                println!("{id:7} -> '{token}'");
            }
        }

        let mut tokens = tokens.get_ids().to_vec();
        let mut generated_tokens = 0usize;

        let eos_token = match self.tokenizer.get_vocab(true).get("END") {
            Some(token) => *token,
            None => anyhow::bail!("cannot find the EOS token"),
        };

        let start_gen = std::time::Instant::now();
        for index in 0..sample_len {
            let context_size = if index > 0 { 1 } else { tokens.len() };
            let ctxt = &tokens[tokens.len().saturating_sub(context_size)..];
            let input = Tensor::new(ctxt, &self.device)?.unsqueeze(0)?;
            let logits = if index > 0 {
                self.model.text_model.forward(&input)?
            } else {
                self.model
                    .text_model
                    .forward_with_img(&input, image_embeds)?
            };
            let logits = logits.squeeze(0)?.to_dtype(DType::F32)?;
            let logits = if self.repeat_penalty == 1. {
                logits
            } else {
                let start_at = tokens.len().saturating_sub(self.repeat_last_n);
                candle_transformers::utils::apply_repeat_penalty(
                    &logits,
                    self.repeat_penalty,
                    &tokens[start_at..],
                )?
            };
            let next_token = self.logits_processor.sample(&logits)?;
            tokens.push(next_token);
            generated_tokens += 1;
            if next_token == eos_token {
                break;
            }
            let token = self.tokenizer.decode(&[next_token], true).map_err(E::msg)?;
            print!("{token}");
            std::io::stdout().flush()?;
        }

        let dt = start_gen.elapsed();
        println!(
            "\n{generated_tokens} tokens generated ({:.2} token/s)",
            generated_tokens as f64 / dt.as_secs_f64()
        );

        Ok(())
    }
}

#[derive(Parser)]
struct Args {
    /// Run on CPU rather than on GPU.
    #[arg(long)]
    cpu: bool,

    /// Enable tracing (generates a trace-timestamp.json file).
    #[arg(long)]
    tracing: bool,

    /// Display the token for the specified prompt.
    #[arg(long)]
    verbose_prompt: bool,

    #[arg(long)]
    prompt: String,

    #[arg(long)]
    image: String,

    /// The temperature used to generate samples.
    #[arg(long)]
    temperature: Option<f64>,

    /// Nucleus sampling probability cutoff.
    #[arg(long)]
    top_p: Option<f64>,

    /// The seed to use when generating random samples.
    #[arg(long, default_value_t = 299792458)]
    seed: u64,

    #[arg(long, default_value_t = 5000)]
    sample_len: usize,

    /// Penalty to be applied for repeating tokens, 1. means no penalty.
    #[arg(long, default_value_t = 1.0)]
    repeat_penalty: f32,

    /// The context size to consider for the repeat penalty.
    #[arg(long, default_value_t = 64)]
    repeat_last_n: usize,

    #[arg(long, default_value = "vikhyatk/moondream2")]
    model_id: String,

    #[arg(long, default_value = "main")]
    revision: String,

    #[arg(long)]
    model_file: Option<String>,

    #[arg(long)]
    tokenizer_file: Option<String>,
}

/// Loads an image from disk using the image crate, this returns a tensor with shape
/// (3, 378, 378).
pub fn load_image<P: AsRef<std::path::Path>>(p: P) -> candle::Result<Tensor> {
    let img = image::io::Reader::open(p)?
        .decode()
        .map_err(candle::Error::wrap)?
        .resize_to_fill(378, 378, image::imageops::FilterType::Triangle); // Adjusted to 378x378
    let img = img.to_rgb8();
    let data = img.into_raw();
    let data = Tensor::from_vec(data, (378, 378, 3), &Device::Cpu)?.permute((2, 0, 1))?;
    let mean = Tensor::new(&[0.5f32, 0.5, 0.5], &Device::Cpu)?.reshape((3, 1, 1))?;
    let std = Tensor::new(&[0.5f32, 0.5, 0.5], &Device::Cpu)?.reshape((3, 1, 1))?;
    (data.to_dtype(candle::DType::F32)? / 255.)?
        .broadcast_sub(&mean)?
        .broadcast_div(&std)
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    use tracing_chrome::ChromeLayerBuilder;
    use tracing_subscriber::prelude::*;

    let args = Args::parse();

    let _guard = if args.tracing {
        let (chrome_layer, guard) = ChromeLayerBuilder::new().build();
        tracing_subscriber::registry().with(chrome_layer).init();
        Some(guard)
    } else {
        None
    };
    println!(
        "avx: {}, neon: {}, simd128: {}, f16c: {}",
        candle::utils::with_avx(),
        candle::utils::with_neon(),
        candle::utils::with_simd128(),
        candle::utils::with_f16c()
    );
    println!(
        "temp: {:.2} repeat-penalty: {:.2} repeat-last-n: {}",
        args.temperature.unwrap_or(0.),
        args.repeat_penalty,
        args.repeat_last_n
    );

    let start = std::time::Instant::now();
    let api = hf_hub::api::tokio::Api::new()?;
    let repo = api.repo(hf_hub::Repo::with_revision(
        args.model_id,
        hf_hub::RepoType::Model,
        args.revision,
    ));
    let model_file = match args.model_file {
        Some(m) => m.into(),
        None => repo.get("model.safetensors").await?,
    };
    let tokenizer = match args.tokenizer_file {
        Some(m) => m.into(),
        None => repo.get("tokenizer.json").await?,
    };
    println!("retrieved the files in {:?}", start.elapsed());
    let tokenizer = Tokenizer::from_file(tokenizer).map_err(E::msg)?;

    let start = std::time::Instant::now();
    let device = candle_examples::device(args.cpu)?;
    let vb = unsafe { VarBuilder::from_mmaped_safetensors(&[model_file], DType::F32, &device)? };
    let config = moondream::Config::v2();
    let model = moondream::Model::new(&config, vb)?;
    println!("loaded the model in {:?}", start.elapsed());

    let start = std::time::Instant::now();
    let image = load_image(args.image)?.to_device(&device)?;
    let image_embeds = image.unsqueeze(0)?;
    let image_embeds = image_embeds.apply(model.vision_encoder())?;
    println!(
        "loaded and encoded the image {image:?} in {:?}",
        start.elapsed()
    );

    let prompt = format!("\n\nQuestion: {0}\n\nAnswer:", args.prompt);

    let mut pipeline = TextGeneration::new(
        model,
        tokenizer,
        args.seed,
        args.temperature,
        args.top_p,
        args.repeat_penalty,
        args.repeat_last_n,
        args.verbose_prompt,
        &device,
    );
    pipeline.run(&prompt, &image_embeds, args.sample_len)?;

    Ok(())
}