use super::photo::Photo;
use crate::constants::{PHOTO_BASE_XY, PHOTO_FULLSIZE_XY, PHOTO_THUMBNAIL_XY};
use crate::error::DichroismError;
use crate::result::Result;
use base64::decode;
use image::imageops::FilterType;
use image::GenericImageView;
use once_cell::sync::Lazy;
use regex::Regex;

static DATA_URI_RE: Lazy<Regex> = Lazy::new(|| {
    Regex::new("^data:image/(png|jpeg);base64,(?P<data>.+)")
        .expect("Couldn't parse data URI Regex.")
});

pub struct PhotoSet {
    pub original: Photo,  // original, just for safe-keeping
    pub fullsize: Photo,  // full-size, "zoomed" view
    pub base: Photo,      // basic viewing
    pub thumbnail: Photo, // tiny, square thumbnail
}

impl PhotoSet {
    pub fn from_photos(original: Photo, fullsize: Photo, base: Photo, thumbnail: Photo) -> Self {
        Self {
            original,
            fullsize,
            base,
            thumbnail,
        }
    }

    pub fn from_data_uri(uri: &str) -> Result<Self> {
        let data = DATA_URI_RE
            .captures(uri)
            .ok_or(DichroismError::UriDataExtract)?
            .name("data")
            .ok_or(DichroismError::UriDataExtract)?
            .as_str();
        let original = image::load_from_memory(&decode(data)?)?;
        let fullsize = original.resize(PHOTO_FULLSIZE_XY, PHOTO_FULLSIZE_XY, FilterType::Lanczos3);
        let base = original.resize(PHOTO_BASE_XY, PHOTO_BASE_XY, FilterType::Lanczos3);

        let (width, height) = original.dimensions();
        let thumbnail = if width > height {
            let offset = (width - height) / 2;
            original.crop_imm(offset, 0, width - offset * 2, height)
        } else {
            let offset = (height - width) / 2;
            original.crop_imm(0, offset, width, height - offset * 2)
        }
        .resize(PHOTO_THUMBNAIL_XY, PHOTO_THUMBNAIL_XY, FilterType::Lanczos3);

        Ok(Self {
            original: Photo::from_image(&original)?,
            fullsize: Photo::from_image(&fullsize)?,
            base: Photo::from_image(&base)?,
            thumbnail: Photo::from_image(&thumbnail)?,
        })
    }
}