use anyhow::{anyhow, Context, Result};
use chrono::DateTime;
use chrono::Duration;
use chrono::NaiveDateTime;
use chrono::Utc;
use compress_tools::{list_archive_files, uncompress_archive_file};
use dotenv::dotenv;
use futures::future::try_join_all;
use futures::stream::TryStreamExt;
use reqwest::Response;
use scraper::{Html, Selector};
use serde::{Deserialize, Serialize};
use serde_json::Value;
use skyrim_cell_dump::parse_plugin;
use sqlx::postgres::PgPoolOptions;
use std::convert::TryInto;
use std::env;
use std::fs::OpenOptions;
use std::io::Seek;
use std::io::SeekFrom;
use tempfile::tempfile;
use tokio::io::{AsyncReadExt, AsyncSeekExt};
use tokio::time::sleep;
use tokio_util::compat::FuturesAsyncReadCompatExt;
use zip::write::{FileOptions, ZipWriter};

static USER_AGENT: &str = "mod-mapper/0.1";
static GAME_NAME: &str = "skyrimspecialedition";
const GAME_ID: u32 = 1704;

#[derive(Debug, Serialize, Deserialize)]
struct Game {
    id: i32,
    name: String,
    nexus_game_id: i32,
    updated_at: NaiveDateTime,
    created_at: NaiveDateTime,
}

#[derive(Debug, Serialize, Deserialize)]
struct Mod {
    id: i32,
    name: String,
    nexus_mod_id: i32,
    author: String,
    category: String,
    description: Option<String>,
    game_id: i32,
    updated_at: NaiveDateTime,
    created_at: NaiveDateTime,
}

#[derive(Debug, Serialize, Deserialize)]
struct File {
    id: i32,
    name: String,
    file_name: String,
    nexus_file_id: i32,
    mod_id: i32,
    category: Option<String>,
    version: Option<String>,
    mod_version: Option<String>,
    uploaded_at: NaiveDateTime,
    updated_at: NaiveDateTime,
    created_at: NaiveDateTime,
}

#[derive(Debug, Serialize, Deserialize)]
struct Plugin {
    id: i32,
    name: String,
    hash: i64,
    file_id: i32,
    version: Option<f64>,
    author: Option<String>,
    description: Option<String>,
    masters: Option<Vec<String>>,
    updated_at: NaiveDateTime,
    created_at: NaiveDateTime,
}

#[derive(Debug, Serialize, Deserialize)]
struct Cell {
    id: i32,
    form_id: i32,
    x: Option<i32>,
    y: Option<i32>,
    is_persistent: bool,
    updated_at: NaiveDateTime,
    created_at: NaiveDateTime,
}

#[derive(Debug, Serialize, Deserialize)]
struct PluginCell {
    id: i32,
    plugin_id: i32,
    cell_id: i32,
    editor_id: Option<String>,
    updated_at: NaiveDateTime,
    created_at: NaiveDateTime,
}

async fn insert_game(
    pool: &sqlx::Pool<sqlx::Postgres>,
    name: &str,
    nexus_game_id: i32,
) -> Result<Game> {
    sqlx::query_as!(
        Game,
        "INSERT INTO games
            (name, nexus_game_id, created_at, updated_at)
            VALUES ($1, $2, now(), now())
            ON CONFLICT (nexus_game_id, name) DO UPDATE SET (name, updated_at) = (EXCLUDED.name, now())
            RETURNING *",
        name,
        nexus_game_id
    )
    .fetch_one(pool)
    .await
    .context("Failed to insert game")
}

async fn insert_mod(
    pool: &sqlx::Pool<sqlx::Postgres>,
    name: &str,
    nexus_mod_id: i32,
    author: &str,
    category: &str,
    description: Option<&str>,
    game_id: i32,
) -> Result<Mod> {
    sqlx::query_as!(
        Mod,
        "INSERT INTO mods
            (name, nexus_mod_id, author, category, description, game_id, created_at, updated_at)
            VALUES ($1, $2, $3, $4, $5, $6, now(), now())
            ON CONFLICT (game_id, nexus_mod_id) DO UPDATE
            SET (name, author, category, description, updated_at) =
            (EXCLUDED.name, EXCLUDED.author, EXCLUDED.category, EXCLUDED.description, now())
            RETURNING *",
        name,
        nexus_mod_id,
        author,
        category,
        description,
        game_id
    )
    .fetch_one(pool)
    .await
    .context("Failed to insert mod")
}

async fn insert_file(
    pool: &sqlx::Pool<sqlx::Postgres>,
    name: &str,
    file_name: &str,
    nexus_file_id: i32,
    mod_id: i32,
    category: Option<&str>,
    version: Option<&str>,
    mod_version: Option<&str>,
    uploaded_at: NaiveDateTime,
) -> Result<File> {
    sqlx::query_as!(
        File,
        "INSERT INTO files
            (name, file_name, nexus_file_id, mod_id, category, version, mod_version, uploaded_at, created_at, updated_at)
            VALUES ($1, $2, $3, $4, $5, $6, $7, $8, now(), now())
            ON CONFLICT (mod_id, nexus_file_id) DO UPDATE
            SET (name, file_name, category, version, mod_version, uploaded_at, updated_at) =
            (EXCLUDED.name, EXCLUDED.file_name, EXCLUDED.category, EXCLUDED.version, EXCLUDED.mod_version, EXCLUDED.uploaded_at, now())
            RETURNING *",
        name,
        file_name,
        nexus_file_id,
        mod_id,
        category,
        version,
        mod_version,
        uploaded_at
    )
    .fetch_one(pool)
    .await
    .context("Failed to insert file")
}

async fn insert_plugin(
    pool: &sqlx::Pool<sqlx::Postgres>,
    name: &str,
    hash: i64,
    file_id: i32,
    version: Option<f64>,
    author: Option<&str>,
    description: Option<&str>,
    masters: Option<&[String]>,
) -> Result<Plugin> {
    sqlx::query_as!(
        Plugin,
        "INSERT INTO plugins
            (name, hash, file_id, version, author, description, masters, created_at, updated_at)
            VALUES ($1, $2, $3, $4, $5, $6, $7, now(), now())
            ON CONFLICT (file_id, name) DO UPDATE
            SET (hash, version, author, description, masters, updated_at) =
            (EXCLUDED.hash, EXCLUDED.version, EXCLUDED.author, EXCLUDED.description, EXCLUDED.masters, now())
            RETURNING *",
        name,
        hash,
        file_id,
        version,
        author,
        description,
        masters
    )
    .fetch_one(pool)
    .await
    .context("Failed to insert plugin")
}

async fn insert_cell(
    pool: &sqlx::Pool<sqlx::Postgres>,
    form_id: i32,
    x: Option<i32>,
    y: Option<i32>,
    is_persistent: bool,
) -> Result<Cell> {
    sqlx::query_as!(
        Cell,
        "INSERT INTO cells
            (form_id, x, y, is_persistent, created_at, updated_at)
            VALUES ($1, $2, $3, $4, now(), now())
            ON CONFLICT (form_id) DO UPDATE
            SET (x, y, is_persistent, updated_at) =
            (EXCLUDED.x, EXCLUDED.y, EXCLUDED.is_persistent, now())
            RETURNING *",
        form_id,
        x,
        y,
        is_persistent
    )
    .fetch_one(pool)
    .await
    .context("Failed to insert cell")
}

async fn insert_plugin_cell(
    pool: &sqlx::Pool<sqlx::Postgres>,
    plugin_id: i32,
    cell_id: i32,
    editor_id: Option<String>,
) -> Result<PluginCell> {
    sqlx::query_as!(
        PluginCell,
        "INSERT INTO plugin_cells
            (plugin_id, cell_id, editor_id, created_at, updated_at)
            VALUES ($1, $2, $3, now(), now())
            ON CONFLICT (plugin_id, cell_id) DO UPDATE
            SET (editor_id, updated_at) = (EXCLUDED.editor_id, now())
            RETURNING *",
        plugin_id,
        cell_id,
        editor_id,
    )
    .fetch_one(pool)
    .await
    .context("Failed to insert cell")
}

fn rate_limit_wait_duration(res: &Response) -> Result<Option<std::time::Duration>> {
    let daily_remaining = res
        .headers()
        .get("X-RL-Daily-Remaining")
        .expect("No daily limit in response headers");
    let hourly_remaining = res
        .headers()
        .get("X-RL-Hourly-Remaining")
        .expect("No hourly limit in response headers");
    let hourly_reset = res
        .headers()
        .get("X-RL-Hourly-Reset")
        .expect("No hourly reset in response headers");
    dbg!(daily_remaining);
    dbg!(hourly_remaining);

    if hourly_remaining == "0" {
        let hourly_reset = hourly_reset.to_str()?.trim();
        let hourly_reset: DateTime<Utc> =
            (DateTime::parse_from_str(hourly_reset, "%Y-%m-%d %H:%M:%S %z")?
                + Duration::seconds(5))
            .into();
        dbg!(hourly_reset);
        let duration = (hourly_reset - Utc::now()).to_std()?;
        dbg!(duration);

        return Ok(Some(duration));
    }

    Ok(None)
}

#[tokio::main]
pub async fn main() -> Result<()> {
    dotenv().ok();
    let pool = PgPoolOptions::new()
        .max_connections(5)
        .connect(&env::var("DATABASE_URL")?)
        .await?;
    let game = insert_game(&pool, GAME_NAME, GAME_ID as i32).await?;
    let client = reqwest::Client::new();

    let mut page: i32 = 1;
    let mut last_page: i32 = 1;

    while page <= last_page {
        let res = client
            .get(format!(
                "https://www.nexusmods.com/Core/Libs/Common/Widgets/ModList?RH_ModList=nav:true,home:false,type:0,user_id:0,game_id:{},advfilt:true,include_adult:true,page_size:80,show_game_filter:false,open:false,page:{},sort_by:OLD_u_downloads",
                GAME_ID,
                page
            ))
            .send()
            .await?
            .error_for_status()?;
        let html = res.text().await?;
        let document = Html::parse_document(&html);
        let mod_select = Selector::parse("li.mod-tile").expect("failed to parse CSS selector");
        let left_select =
            Selector::parse("div.mod-tile-left").expect("failed to parse CSS selector");
        let right_select =
            Selector::parse("div.mod-tile-right").expect("failed to parse CSS selector");
        let name_select = Selector::parse("p.tile-name a").expect("failed to parse CSS selector");
        let category_select =
            Selector::parse("div.category a").expect("failed to parse CSS selector");
        let author_select = Selector::parse("div.author a").expect("failed to parse CSS selector");
        let desc_select = Selector::parse("p.desc").expect("failed to parse CSS selector");
        let last_page_select =
            Selector::parse("div.pagination li.extra a").expect("failed to parse CSS selector");

        let last_page_elem = document
            .select(&last_page_select)
            .next()
            .expect("Missing last page link");
        last_page = last_page_elem
            .text()
            .next()
            .expect("Missing last page text")
            .trim()
            .parse::<i32>()
            .ok()
            .expect("Failed to parse last page");

        let mods = try_join_all(document.select(&mod_select).map(|element| {
            let left = element
                .select(&left_select)
                .next()
                .expect("Missing left div for mod");
            let right = element
                .select(&right_select)
                .next()
                .expect("Missing right div for mod");
            let nexus_mod_id = left
                .value()
                .attr("data-mod-id")
                .expect("Missing mod id attribute")
                .parse::<i32>()
                .ok()
                .expect("Failed to parse mod id");
            let name_elem = right
                .select(&name_select)
                .next()
                .expect("Missing name link for mod");
            let name = name_elem.text().next().expect("Missing name text for mod");
            let category_elem = right
                .select(&category_select)
                .next()
                .expect("Missing category link for mod");
            let category = category_elem
                .text()
                .next()
                .expect("Missing category text for mod");
            let author_elem = right
                .select(&author_select)
                .next()
                .expect("Missing author link for mod");
            let author = author_elem
                .text()
                .next()
                .expect("Missing author text for mod");
            let desc_elem = right
                .select(&desc_select)
                .next()
                .expect("Missing desc elem for mod");
            let desc = desc_elem.text().next();
            insert_mod(&pool, name, nexus_mod_id, author, category, desc, game.id)
        }))
        .await?;

        for mod_obj in mods {
            dbg!(&mod_obj);
            let res = client
                .get(format!(
                    "https://api.nexusmods.com/v1/games/{}/mods/{}/files.json",
                    GAME_NAME, mod_obj.nexus_mod_id
                ))
                .header("accept", "application/json")
                .header("apikey", env::var("NEXUS_API_KEY")?)
                .header("user-agent", USER_AGENT)
                .send()
                .await?
                .error_for_status()?;

            if let Some(duration) = rate_limit_wait_duration(&res)? {
                sleep(duration).await;
            }

            let files = res.json::<Value>().await?;
            let files = files
                .get("files")
                .ok_or_else(|| anyhow!("Missing files key in API response"))?
                .as_array()
                .ok_or_else(|| anyhow!("files value in API response is not an array"))?;
            // TODO: download other files than just MAIN files
            let files = files.into_iter().filter(|file| {
                if let Some(category_name) = file.get("category_name") {
                    category_name.as_str() == Some("MAIN")
                } else {
                    false
                }
            });

            for file in files {
                let file_id = file
                    .get("file_id")
                    .ok_or_else(|| anyhow!("Missing file_id key in file in API response"))?
                    .as_i64()
                    .ok_or_else(|| anyhow!("file_id value in API response file is not a number"))?;
                dbg!(file_id);
                let name = file
                    .get("name")
                    .ok_or_else(|| anyhow!("Missing name key in file in API response"))?
                    .as_str()
                    .ok_or_else(|| anyhow!("name value in API response file is not a string"))?;
                let file_name = file
                    .get("file_name")
                    .ok_or_else(|| anyhow!("Missing file_name key in file in API response"))?
                    .as_str()
                    .ok_or_else(|| {
                        anyhow!("file_name value in API response file is not a string")
                    })?;
                let category = file
                    .get("category_name")
                    .ok_or_else(|| anyhow!("Missing category key in file in API response"))?
                    .as_str();
                let version = file
                    .get("version")
                    .ok_or_else(|| anyhow!("Missing version key in file in API response"))?
                    .as_str();
                let mod_version = file
                    .get("mod_version")
                    .ok_or_else(|| anyhow!("Missing mod_version key in file in API response"))?
                    .as_str();
                let uploaded_timestamp = file
                    .get("uploaded_timestamp")
                    .ok_or_else(|| {
                        anyhow!("Missing uploaded_timestamp key in file in API response")
                    })?
                    .as_i64()
                    .ok_or_else(|| {
                        anyhow!("uploaded_timestamp value in API response file is not a number")
                    })?;
                let uploaded_at = NaiveDateTime::from_timestamp(uploaded_timestamp, 0);
                let db_file = insert_file(
                    &pool,
                    name,
                    file_name,
                    file_id as i32,
                    mod_obj.id,
                    category,
                    version,
                    mod_version,
                    uploaded_at,
                )
                .await?;
                let res = client
                    .get(format!(
                        "https://api.nexusmods.com/v1/games/{}/mods/{}/files/{}/download_link.json",
                        GAME_NAME, mod_obj.nexus_mod_id, file_id
                    ))
                    .header("accept", "application/json")
                    .header("apikey", env::var("NEXUS_API_KEY")?)
                    .header("user-agent", USER_AGENT)
                    .send()
                    .await?
                    .error_for_status()?;

                let links = res.json::<Value>().await?;
                let link = links
                    .get(0)
                    .ok_or_else(|| anyhow!("Links array in API response is missing first element"))?
                    .get("URI")
                    .ok_or_else(|| anyhow!("Missing URI key in link in API response"))?
                    .as_str()
                    .ok_or_else(|| anyhow!("URI value in API response link is not a string"))?;

                let mut tokio_file = tokio::fs::File::from_std(tempfile()?);
                let res = client
                    .get(link)
                    .header("apikey", env::var("NEXUS_API_KEY")?)
                    .header("user-agent", USER_AGENT)
                    .send()
                    .await?
                    .error_for_status()?;

                let duration = rate_limit_wait_duration(&res)?;

                // See: https://github.com/benkay86/async-applied/blob/master/reqwest-tokio-compat/src/main.rs
                let mut byte_stream = res
                    .bytes_stream()
                    .map_err(|e| futures::io::Error::new(futures::io::ErrorKind::Other, e))
                    .into_async_read()
                    .compat();

                tokio::io::copy(&mut byte_stream, &mut tokio_file).await?;

                // let bytes = res.bytes().await?;
                // let reader = std::io::Cursor::new(&bytes);

                let mut plugin_archive = ZipWriter::new(
                    OpenOptions::new()
                        .write(true)
                        .create(true)
                        .open("plugins.zip")?,
                );
                plugin_archive.add_directory(
                    format!("{}/{}/{}", GAME_NAME, mod_obj.nexus_mod_id, file_id),
                    FileOptions::default(),
                )?;
                plugin_archive.finish()?;

                let mut plugin_archive = ZipWriter::new_append(
                    OpenOptions::new()
                        .read(true)
                        .write(true)
                        .open("plugins.zip")?,
                )?;
                let mut initial_bytes = [0; 8];
                tokio_file.seek(SeekFrom::Start(0)).await?;
                tokio_file.read_exact(&mut initial_bytes).await?;
                let kind = infer::get(&initial_bytes).expect("unknown file type of file download");
                match kind.mime_type() {
                    // "application/zip" => {
                    //     let mut archive = ZipArchive::new(reader)?;
                    //     let mut plugin_file_paths = Vec::new();
                    //     for file_name in archive.file_names() {
                    //         dbg!(file_name);
                    //         if file_name.ends_with(".esp")
                    //             || file_name.ends_with(".esm")
                    //             || file_name.ends_with(".esl")
                    //         {
                    //             plugin_file_paths.push(file_name.to_string());
                    //         }
                    //     }
                    //     dbg!(&plugin_file_paths);
                    //     for file_name in plugin_file_paths.iter() {
                    //         let mut file = archive.by_name(file_name)?;
                    //         let plugin = parse_plugin(file)?;
                    //         dbg!(plugin);
                    //         plugin_archive.start_file(
                    //             format!("{}/{}/{}/{}", GAME_NAME, mod_id, file_id, file_name),
                    //             FileOptions::default(),
                    //         )?;
                    //         std::io::copy(&mut file, &mut plugin_archive)?;
                    //     }
                    // }
                    _ => {
                        tokio_file.seek(SeekFrom::Start(0)).await?;
                        let mut file = tokio_file.into_std().await;
                        let mut plugin_file_paths = Vec::new();
                        for file_name in list_archive_files(&file)? {
                            if file_name.ends_with(".esp")
                                || file_name.ends_with(".esm")
                                || file_name.ends_with(".esl")
                            {
                                plugin_file_paths.push(file_name);
                            }
                        }
                        for file_name in plugin_file_paths.iter() {
                            file.seek(SeekFrom::Start(0))?;
                            dbg!(file_name);
                            let mut buf = Vec::default();
                            uncompress_archive_file(&mut file, &mut buf, file_name)?;
                            let plugin = parse_plugin(&buf)?;
                            let hash = seahash::hash(&buf);
                            let plugin_row = insert_plugin(
                                &pool,
                                name,
                                hash as i64,
                                db_file.id,
                                Some(plugin.header.version as f64),
                                plugin.header.author,
                                plugin.header.description,
                                Some(
                                    &plugin
                                        .header
                                        .masters
                                        .iter()
                                        .map(|s| s.to_string())
                                        .collect::<Vec<String>>(),
                                ),
                            )
                            .await?;
                            for cell in plugin.cells {
                                let cell_row = insert_cell(
                                    &pool,
                                    cell.form_id.try_into().unwrap(),
                                    cell.x,
                                    cell.y,
                                    cell.is_persistent,
                                )
                                .await?;
                                insert_plugin_cell(
                                    &pool,
                                    plugin_row.id,
                                    cell_row.id,
                                    cell.editor_id,
                                )
                                .await?;
                            }
                            plugin_archive.start_file(
                                format!(
                                    "{}/{}/{}/{}",
                                    GAME_NAME, mod_obj.nexus_mod_id, file_id, file_name
                                ),
                                FileOptions::default(),
                            )?;
                            std::io::copy(&mut buf.as_slice(), &mut plugin_archive)?;
                        }
                    }
                };

                plugin_archive.finish()?;
                if let Some(duration) = duration {
                    sleep(duration).await;
                }
            }
        }

        page += 1;
    }

    Ok(())
}