use teloxide::prelude::*;
use teloxide::{
    net::Download,
    requests::{Requester,MultipartRequest},
    types::{MessageEntity, MessageEntityKind},
    payloads::SendPhoto,
    Bot,
};
use image::{DynamicImage,GenericImageView};
use std::io::Cursor;
use tokio::io::BufStream;
use crate::telegram_utils::*;

const TOLERANCE: i16 = 10;
const PERCENT_ACEPTANCE: u8 = 5;
const WHITE : u8 = 160;
const WHITE_ACEPTANCE: u8 = 40;

fn check_percent(img: DynamicImage) -> (u8,u8) {
    let mut cont = 0;
    let mut cont_wite = 0;
    for pixel in img.pixels() {
        let diference_rg:i16 = (pixel.2[0] as i16 - pixel.2[1] as i16).abs();
        let diference_gb:i16 = (pixel.2[1] as i16 - pixel.2[2] as i16).abs();
        let diference_br:i16 = (pixel.2[0] as i16 - pixel.2[2] as i16).abs();
        let diference_pixel = diference_rg + diference_gb + diference_br;
        if pixel.2[0] > WHITE && pixel.2[1] > WHITE && pixel.2[2] > WHITE {
            cont_wite+=1
        }
        if diference_pixel > TOLERANCE {
            cont += 1;
        }
    }
    let percent = ((cont as f64 /(img.width() * img.height()) as f64)*100.0) as u8;
    let white = ((cont_wite as f64 /(img.width() * img.height()) as f64)*100.0) as u8;
    (percent,white)
}

pub fn append_text(new_msg: MultipartRequest<SendPhoto>, old_msg: Message) -> MultipartRequest<SendPhoto> {
    match old_msg.caption() {
        Some(caption) => {
            let mut msg_from = get_alias(&old_msg);
            msg_from.push_str(": ");
            msg_from = String::from("Mensaje de ") + &msg_from;
            let from_offset = msg_from.encode_utf16().count();
            //new_msg.caption(caption).caption_entities(generate_entity_spoiler(caption.len())).has_spoiler(true)
            new_msg.caption(msg_from + caption).caption_entities(generate_captions(old_msg.caption_entities().unwrap().to_vec(),caption.encode_utf16().count(), from_offset))
        },
        None => new_msg,
    }
}

pub fn generate_captions(captions: Vec<MessageEntity>, len: usize, offset: usize) -> Vec<MessageEntity> {
    let mut ret = Vec::new();
    let mut last_hole = 0;
    for mut cap in captions {
        match cap.kind {
            MessageEntityKind::TextMention { user: ref User } => {
                if cap.offset == 0 {
                    last_hole = cap.length;
                }else if cap.offset >= last_hole {
                    ret.push(MessageEntity::spoiler(last_hole+offset,cap.offset-last_hole));
                    last_hole = cap.offset + cap.length;
                }
                cap.offset += offset;
                ret.push(cap.clone());
            },
            _ => continue,
        }
    }
    if last_hole < len {
        ret.push(MessageEntity::spoiler(last_hole+offset,len - last_hole));
    }
    ret
}
pub async fn check_image(msg: Message, bot: Bot) -> anyhow::Result<()> {
    match msg.photo() {
        Some(s) => {
            let mut percent = 0;
            let mut white = 0;
            let mut id : Option<(String, u32)> = None;
            let mut failed = true;
            for p in s {
                let file = bot.get_file(p.file.id.clone()).await?;
                let empty_memory: Vec<u8> = Vec::new();
                let cursor = Cursor::new(empty_memory);
                let mut reader = BufStream::new(cursor);
                bot.download_file(&file.path, &mut reader).await?;
                let raw = reader.into_inner().into_inner().leak();
                match image::load_from_memory(raw) {
                    Ok(img) => {
                        failed = false;
                        let img_percent = check_percent(img);
                        if img_percent.0 >= percent {
                            percent = img_percent.0;
                            white = img_percent.1;
                            id = match id {
                                Some(i) => {
                                    if i.1 > p.width {
                                        Some((p.clone().file.id, p.clone().width))
                                    } else {
                                        Some(i)
                                    }
                                },
                                None => Some((p.clone().file.id, p.clone().width)),
                            }
                        }
                    },
                    Err(_e) => continue,
                }
            }
            if !failed && percent < PERCENT_ACEPTANCE && white > WHITE_ACEPTANCE {
                bot.delete_message(msg.chat.id, msg.id).await?;
                let response = match id {
                    Some(i) => bot.send_photo(msg.chat.id, teloxide::types::InputFile::file_id(i.0)).has_spoiler(true),
                    None => {
                        match msg.photo().unwrap().iter().max_by_key(|p| p.width) {
                            Some(f) => bot.send_photo(msg.chat.id, teloxide::types::InputFile::file_id(f.file.id.clone())).has_spoiler(true),
                            None => return Ok(()),
                        }
                    },
                };
                append_text(response, msg).await?;
            }
            Ok(())
        },
        None => Ok(()),
    }
}