use lazy_static::lazy_static;
use regex::{Captures, Regex};
use sqlx::query_as;
use std::collections::HashMap;

use crate::{
    ctx::Ctx,
    db::models::Post,
    error::NekrochanError,
    perms::PermissionWrapper,
    trip::{secure_tripcode, tripcode},
};

lazy_static! {
    pub static ref NAME_REGEX: Regex =
        Regex::new(r"^([^#].*?)?(?:(##([^ ].*?)|#([^#].*?)))?(##( .*?)?)?$").unwrap();
    pub static ref QUOTE_REGEX: Regex = Regex::new(r">>(\d+)").unwrap();
    pub static ref GREENTEXT_REGEX: Regex = Regex::new(r"(?mR)^>(.*)$").unwrap();
    pub static ref ORANGETEXT_REGEX: Regex = Regex::new(r"(?mR)^<(.*)$").unwrap();
    pub static ref REDTEXT_REGEX: Regex = Regex::new(r"==(.+?)==").unwrap();
    pub static ref BLUETEXT_REGEX: Regex = Regex::new(r"--(.+?)--").unwrap();
    pub static ref GLOWTEXT_REGEX: Regex = Regex::new(r"\%\%(.+?)\%\%").unwrap();
    pub static ref UH_OH_TEXT_REGEX: Regex = Regex::new(r"\(\(\((.+?)\)\)\)").unwrap();
    pub static ref SPOILER_REGEX: Regex = Regex::new(r"\|\|([\s\S]+?)\|\|").unwrap();
    pub static ref URL_REGEX: Regex =
        Regex::new(r"https?\:&#x2F;&#x2F;[^\s<>\[\]{}|\\^]+").unwrap();
    pub static ref JANNYTEXT_REGEX: Regex = Regex::new(r"##(.+?)##").unwrap();
}

pub fn parse_name(
    ctx: &Ctx,
    perms: &PermissionWrapper,
    anon_name: &str,
    name: &str,
) -> Result<(String, Option<String>, Option<String>), NekrochanError> {
    let Some(captures) = NAME_REGEX.captures(name) else {
        return Ok((anon_name.to_owned(), None, None));
    };

    let name = match captures.get(1) {
        Some(name) => {
            let name = name.as_str().to_owned();

            if name.len() > 32 {
                return Err(NekrochanError::PostNameFormatError);
            }

            name
        }
        None => anon_name.to_owned(),
    };

    let tripcode = match captures.get(2) {
        Some(_) => {
            let strip = captures.get(3);
            let itrip = captures.get(4);

            if let Some(strip) = strip {
                let trip = secure_tripcode(strip.as_str(), &ctx.cfg.secrets.secure_trip);

                Some(format!("!!{trip}"))
            } else if let Some(itrip) = itrip {
                let trip = tripcode(itrip.as_str());

                Some(format!("!{trip}"))
            } else {
                None
            }
        }
        None => None,
    };

    if !(perms.owner() || perms.capcodes()) {
        return Ok((name, tripcode, None));
    }

    let capcode = match captures.get(5) {
        Some(_) => match captures.get(6) {
            Some(capcode) => {
                let capcode: String = capcode.as_str().trim().into();

                if capcode.is_empty() || !(perms.owner() || perms.custom_capcodes()) {
                    Some(capcode_fallback(perms.owner()))
                } else {
                    if capcode.len() > 32 {
                        return Err(NekrochanError::CapcodeFormatError);
                    }

                    Some(capcode)
                }
            }
            None => Some(capcode_fallback(perms.owner())),
        },
        None => None,
    };

    Ok((name, tripcode, capcode))
}

fn capcode_fallback(owner: bool) -> String {
    if owner {
        "Admin".into()
    } else {
        "Uklízeč".into()
    }
}

pub async fn markup(
    ctx: &Ctx,
    perms: &PermissionWrapper,
    board: Option<String>,
    op: Option<i64>,
    text: &str,
) -> Result<String, NekrochanError> {
    let text = escape_html(text);

    let text = if let Some(board) = board {
        let quoted_posts = get_quoted_posts(ctx, &board, &text).await?;

        let text = QUOTE_REGEX.replace_all(&text, |captures: &Captures| {
            let id_raw = &captures[1];

            let Ok(id) = id_raw.parse() else {
                return format!("<span class=\"dead-quote\">&gt;&gt;{id_raw}</span>");
            };

            let post = quoted_posts.get(&id);

            if let Some(post) = post {
                format!(
                    "<a class=\"quote\" href=\"{}\">&gt;&gt;{}</a>{}",
                    post.post_url(),
                    post.id,
                    if op == Some(post.id) {
                        " <span class=\"small\">(OP)</span>"
                    } else {
                        ""
                    }
                )
            } else {
                format!("<span class=\"dead-quote\">&gt;&gt;{id}</span>")
            }
        });

        text.to_string()
    } else {
        text
    };

    let text = GREENTEXT_REGEX.replace_all(&text, "<span class=\"greentext\">&gt;$1</span>");
    let text = ORANGETEXT_REGEX.replace_all(&text, "<span class=\"orangetext\">&lt;$1</span>");
    let text = REDTEXT_REGEX.replace_all(&text, "<span class=\"redtext\">$1</span>");
    let text = BLUETEXT_REGEX.replace_all(&text, "<span class=\"bluetext\">$1</span>");
    let text = GLOWTEXT_REGEX.replace_all(&text, "<span class=\"glowtext\">$1</span>");
    let text = SPOILER_REGEX.replace_all(&text, "<span class=\"spoiler\">$1</span>");

    let text = UH_OH_TEXT_REGEX.replace_all(&text, |captures: &Captures| {
        format!(
            "<span class=\"uh-oh-text\">((( {} )))</span>",
            captures[1].trim()
        )
    });

    let text = URL_REGEX.replace_all(&text, |captures: &Captures| {
        let url = &captures[0];

        format!("<a rel=\"nofollow\" href=\"{url}\">{url}</a>")
    });

    let text = if perms.owner() || perms.jannytext() {
        JANNYTEXT_REGEX.replace_all(&text, "<span class=\"jannytext\">$1</span>")
    } else {
        text
    };

    Ok(text.to_string())
}

fn escape_html(text: &str) -> String {
    text.replace('&', "&amp;")
        .replace('\'', "&#39;")
        .replace('/', "&#x2F;")
        .replace('`', "&#x60;")
        .replace('=', "&#x3D;")
        .replace('<', "&lt;")
        .replace('>', "&gt;")
        .replace('"', "&quot;")
}

async fn get_quoted_posts(
    ctx: &Ctx,
    board: &String,
    text: &str,
) -> Result<HashMap<i64, Post>, NekrochanError> {
    let mut quoted_ids: Vec<i64> = Vec::new();

    for quote in QUOTE_REGEX.captures_iter(text) {
        let id_raw = &quote[1];
        let Ok(id) = id_raw.parse() else { continue };

        quoted_ids.push(id);
    }

    if quoted_ids.is_empty() {
        return Ok(HashMap::new());
    }

    let in_list = quoted_ids
        .iter()
        .map(std::string::ToString::to_string)
        .collect::<Vec<_>>()
        .join(",");

    let quoted_posts = query_as(&format!(
        "SELECT * FROM posts_{board} WHERE id IN ({in_list})"
    ))
    .fetch_all(ctx.db())
    .await?
    .into_iter()
    .map(|post: Post| (post.id, post))
    .collect::<HashMap<_, _>>();

    Ok(quoted_posts)
}