use std::{fs::metadata, io::Write, path::Path};

use byteorder::{BigEndian, WriteBytesExt};
use hex::FromHex;
use image::DynamicImage;
use itertools::Itertools;
use md5::Digest;
use serde::{Deserialize, Deserializer, Serialize, Serializer};
use zerocopy::IntoBytes;

use crate::{
  RawImage, RawImageData, RawlerError, Result,
  decoders::{RawDecodeParams, RawMetadata, cr2::Cr2Format, cr3::Cr3Format, dng::DngFormat, iiq::IiqFormat, nef::NefFormat, pef::PefFormat, tfr::TfrFormat},
  formats::tiff::Rational,
  formats::tiff::SRational,
  imgop::{Rect, develop::RawDevelop},
  rawimage::{BlackLevel, WhiteLevel},
  rawsource::RawSource,
};

#[derive(Debug, Clone, PartialEq)]
pub struct Md5Digest {
  digest: md5::Digest,
}

impl From<md5::Digest> for Md5Digest {
  fn from(digest: md5::Digest) -> Self {
    Self { digest }
  }
}

impl Serialize for Md5Digest {
  fn serialize<S>(&self, serializer: S) -> std::result::Result<S::Ok, S::Error>
  where
    S: Serializer,
  {
    let s = format!("{:x}", self.digest);
    serializer.serialize_str(&s)
  }
}

impl<'de> Deserialize<'de> for Md5Digest {
  fn deserialize<D>(deserializer: D) -> std::result::Result<Md5Digest, D::Error>
  where
    D: Deserializer<'de>,
  {
    use serde::de::Error;
    let s = String::deserialize(deserializer)?;
    if s.len() != 32 {
      Err(D::Error::custom(format!("Invalid digest value: {}", s)))
    } else {
      Ok(Md5Digest {
        digest: Digest(<[u8; 16]>::from_hex(s).map_err(D::Error::custom)?),
      })
    }
  }
}

#[derive(Debug, Clone, PartialEq, Default, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct FileMetadata {
  file_size: u64,
  file_name: String,
  digest: Option<Md5Digest>,
}

#[derive(Debug, Clone, PartialEq, Default, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct AnalyzerMetadata {
  pub raw_params: RawParams,
  pub raw_metadata: RawMetadata,
}

#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
#[allow(clippy::large_enum_variant)]
pub enum AnalyzerData {
  FileStructure(FormatDump),
  Metadata(AnalyzerMetadata),
  RawParams(RawParams),
}

#[derive(Debug, Clone, PartialEq, Default, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct AnalyzerResult {
  pub file: FileMetadata,
  pub data: Option<AnalyzerData>,
}

#[derive(Debug, Clone, PartialEq, Default, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct CaptureInfo {
  pub make: String,
  pub model: String,
  pub exposure_time: Option<Rational>,
  pub shutter_speed: Option<SRational>,
  pub exposure_bias: Option<SRational>,
  pub lens_make: Option<String>,
  pub lens_model: Option<String>,
  pub lens_spec: Option<[Rational; 4]>,
}
#[derive(Debug, Clone, PartialEq, Default, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct RawParams {
  pub raw_width: usize,
  pub raw_height: usize,
  pub bit_depth: usize,
  pub crop_area: Option<Rect>,
  pub active_area: Option<Rect>,
  pub blacklevels: BlackLevel,
  pub whitelevels: WhiteLevel,
  pub wb_coeffs: (Option<f32>, Option<f32>, Option<f32>, Option<f32>),
}

impl From<&RawImage> for RawParams {
  fn from(rawimage: &RawImage) -> Self {
    Self {
      raw_width: rawimage.width,
      raw_height: rawimage.height,
      bit_depth: rawimage.bps,
      crop_area: rawimage.crop_area,
      active_area: rawimage.active_area,
      blacklevels: rawimage.blacklevel.clone(),
      whitelevels: rawimage.whitelevel.clone(),
      wb_coeffs: rawimage
        .wb_coeffs
        .iter()
        .map(|c| if c.is_nan() { None } else { Some(*c) })
        .collect_tuple()
        .unwrap(),
    }
  }
}

#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
#[allow(clippy::large_enum_variant)]
pub enum FormatDump {
  Cr3(Cr3Format),
  Cr2(Cr2Format),
  Pef(PefFormat),
  Iiq(IiqFormat),
  Tfr(TfrFormat),
  Nef(NefFormat),
  Dng(DngFormat),
}

fn file_metadata<P: AsRef<Path>>(path: P, rawfile: &RawSource) -> Result<FileMetadata> {
  let fs_meta = metadata(&path).map_err(|e| RawlerError::with_io_error("read metadata", &path, e))?;
  let digest = rawfile.digest();
  Ok(FileMetadata {
    file_name: path.as_ref().file_name().unwrap().to_string_lossy().to_string(),
    file_size: fs_meta.len(),
    digest: Some(digest.into()),
  })
}

pub fn analyze_metadata<P: AsRef<Path>>(path: P) -> Result<AnalyzerResult> {
  //let input = BufReader::new(File::open(&path).map_err(|e| RawlerError::with_io_error("load into buffer", &path, e))?);
  let rawfile = RawSource::new(path.as_ref())?;
  let decoder = crate::get_decoder(&rawfile)?;
  let rawimage = decoder.raw_image(&rawfile, &RawDecodeParams::default(), true)?;

  let mut result = AnalyzerResult {
    file: file_metadata(path, &rawfile)?,
    ..Default::default()
  };

  let md = decoder.raw_metadata(&rawfile, &RawDecodeParams::default())?;
  result.data = Some(AnalyzerData::Metadata(AnalyzerMetadata {
    raw_params: RawParams::from(&rawimage),
    raw_metadata: md,
  }));
  Ok(result)
}

pub fn analyze_file_structure<P: AsRef<Path>>(path: P) -> Result<AnalyzerResult> {
  let rawfile = RawSource::new(path.as_ref())?;
  let decoder = crate::get_decoder(&rawfile)?;

  let result = AnalyzerResult {
    file: file_metadata(path, &rawfile)?,
    data: Some(AnalyzerData::FileStructure(decoder.format_dump())),
  };
  Ok(result)
}

pub fn extract_raw_pixels<P: AsRef<Path>>(path: P, params: &RawDecodeParams) -> Result<RawImage> {
  let rawfile = RawSource::new(path.as_ref())?;
  let decoder = crate::get_decoder(&rawfile)?;
  let rawimage = decoder.raw_image(&rawfile, params, false)?;
  Ok(rawimage)
}

pub fn raw_pixels_digest<P: AsRef<Path>>(path: P, params: &RawDecodeParams) -> Result<[u8; 16]> {
  let rawimage = extract_raw_pixels(path, params)?;
  let byte_buf = match &rawimage.data {
    RawImageData::Integer(items) => items.as_slice().as_bytes(),
    RawImageData::Float(items) => items.as_slice().as_bytes(),
  };
  Ok(md5::compute(byte_buf).into())
}

pub fn extract_full_pixels<P: AsRef<Path>>(path: P, params: &RawDecodeParams) -> Result<DynamicImage> {
  let rawfile = RawSource::new(path.as_ref())?;
  let decoder = crate::get_decoder(&rawfile)?;
  match decoder.full_image(&rawfile, params)? {
    Some(preview) => Ok(preview),
    None => Err("Unable to extract full image from RAW".into()),
  }
}

pub fn extract_preview_pixels<P: AsRef<Path>>(path: P, params: &RawDecodeParams) -> Result<DynamicImage> {
  let rawfile = RawSource::new(path.as_ref())?;
  let decoder = crate::get_decoder(&rawfile)?;
  match decoder.preview_image(&rawfile, params)? {
    Some(preview) => Ok(preview),
    None => match decoder.full_image(&rawfile, params)? {
      Some(preview) => Ok(preview),
      None => Err("Unable to extract preview image from RAW".into()),
    },
  }
}

pub fn extract_thumbnail_pixels<P: AsRef<Path>>(path: P, params: &RawDecodeParams) -> Result<DynamicImage> {
  let rawfile = RawSource::new(path.as_ref())?;
  let decoder = crate::get_decoder(&rawfile)?;
  match decoder.thumbnail_image(&rawfile, params)? {
    Some(thumbnail) => Ok(thumbnail),
    None => match decoder.preview_image(&rawfile, params)? {
      Some(thumbnail) => Ok(thumbnail),
      None => match decoder.full_image(&rawfile, params)? {
        Some(thumbnail) => Ok(thumbnail),
        None => Err("Unable to extract thumbnail image from RAW".into()),
      },
    },
  }
}

pub fn raw_to_srgb<P: AsRef<Path>>(path: P, params: &RawDecodeParams) -> Result<DynamicImage> {
  let rawfile = RawSource::new(path.as_ref())?;
  // Get decoder or return
  let decoder = crate::get_decoder(&rawfile)?;
  //decoder.decode_metadata(&mut rawfile)?;
  let rawimage = decoder.raw_image(&rawfile, params, false)?;
  let dev = RawDevelop::default();
  assert_eq!(rawimage.cpp, 1);
  Ok(dev.develop_intermediate(&rawimage)?.to_dynamic_image().unwrap())
}

/// Dump raw pixel data as PGM
pub fn raw_as_pgm(width: usize, height: usize, buf: &[u16], writer: &mut dyn Write) -> std::io::Result<()> {
  let header = format!("P5 {} {} {}\n", width, height, 65535);
  writer.write_all(header.as_bytes())?;
  for px in buf {
    writer.write_u16::<BigEndian>(*px)?;
  }
  Ok(())
}

/// Dump  pixel data as PGM
pub fn rgb8_as_ppm8(width: usize, height: usize, buf: &[u8], writer: &mut dyn Write) -> std::io::Result<()> {
  let header = format!("P6 {} {} {}\n", width, height, u8::MAX);
  writer.write_all(header.as_bytes())?;
  writer.write_all(buf)?;
  Ok(())
}

/// Dump raw pixel data as PPM
pub fn raw_as_ppm16(width: usize, height: usize, buf: &[u16], writer: &mut dyn Write) -> std::io::Result<()> {
  let header = format!("P6 {} {} {}\n", width, height, 65535);
  writer.write_all(header.as_bytes())?;
  for px in buf {
    writer.write_u16::<BigEndian>(*px)?;
  }
  Ok(())
}