use base64::engine::{general_purpose::URL_SAFE, Engine};
use eframe::egui::TextFormat;
use eframe::epaint::text::LayoutJob;
use flate2::read::GzDecoder;
use gd_plist::Value;
use std::fs::File;
use std::io::{Cursor, Read};
use std::path::PathBuf;

struct User {
    name: String,
    id: Option<u64>,
}

pub enum Song {
    Official { id: i32 /*k8*/ },
    Newgrounds { id: i32 /*k45*/ },
    Unknown,
}

struct Level {
    outer: OuterLevel,
    song: Song,
}

#[derive(Debug)]
pub struct OuterLevel {
    name: String,          // k2
    revision: Option<i64>, // k46
}

impl OuterLevel {
    pub fn load_all() -> Vec<OuterLevel> {
        let plist = get_local_level_plist();
        let levels: Vec<OuterLevel> = plist
            .as_dictionary()
            .and_then(|dict| dict.get("LLM_01"))
            .unwrap()
            .as_dictionary()
            .unwrap()
            .into_iter()
            .filter(|(key, _)| key.as_str() != "_isArr")
            .map(|(_, val)| {
                let mut builder = LevelBuilder::new();
                let props = val.as_dictionary().unwrap();
                if let Some(title) = props.get("k2") {
                    builder.with_name(title.as_string().unwrap().into());
                }
                if let Some(rev) = props.get("k46") {
                    builder.with_revision(rev.as_signed_integer().unwrap().into());
                }
                builder.build_outer_level().unwrap()
            })
            .collect();
        levels
    }

    pub fn display_name(&self) -> LayoutJob {
        match self.revision {
            Some(rev) => {
                let mut job = LayoutJob::default();
                job.append(&format!("{} ", self.name), 0f32, TextFormat::default());
                job.append(
                    &format!("(rev {})", rev),
                    0f32,
                    TextFormat {
                        italics: true,
                        ..Default::default()
                    },
                );
                job
            }
            None => {
                let mut job = LayoutJob::default();
                job.append(&self.name, 0f32, TextFormat::default());
                job
            }
        }
    }
}

pub fn gd_path() -> PathBuf {
    let mut path_buf = home::home_dir().unwrap();
    #[cfg(unix)]
    path_buf.extend(
        [
            ".local",
            "share",
            "Steam",
            "steamapps",
            "compatdata",
            "322170",
            "pfx",
            "drive_c",
            "users",
            "steamuser",
            "AppData",
            "Local",
            "GeometryDash",
        ]
        .iter(),
    );
    #[cfg(windows)]
    path_buf.extend(["AppData", "Local", "GeometryDash"].iter());
    path_buf
}

struct LevelBuilder {
    name: Option<String>,
    song: Option<Song>,
    revision: Option<i64>,
}

impl Default for LevelBuilder {
    fn default() -> Self {
        Self {
            name: None,
            song: None,
            revision: None,
        }
    }
}

impl LevelBuilder {
    fn new() -> Self {
        Self::default()
    }

    fn with_name(&mut self, name: String) {
        self.name = Some(name);
    }

    fn with_song(&mut self, song: Song) {
        self.song = Some(song);
    }

    fn with_revision(&mut self, revision: i64) {
        self.revision = Some(revision);
    }

    fn build_level(self) -> Option<Level> {
        match self {
            Self {
                name: Some(name),
                song: Some(song),
                revision,
            } => Some(Level {
                song,
                outer: OuterLevel { name, revision },
            }),
            _ => None,
        }
    }

    fn build_outer_level(self) -> Option<OuterLevel> {
        match self {
            Self {
                name: Some(name),
                revision,
                ..
            } => Some(OuterLevel { name, revision }),
            _ => None,
        }
    }
}

fn get_local_level_plist() -> Value {
    let raw_save_data = {
        let mut save_file =
            File::open(gd_path().join("CCLocalLevels.dat")).expect("No save file found!");
        let mut sd = Vec::new();
        save_file.read_to_end(&mut sd).unwrap();
        sd
    };
    let data_post_xor: Vec<u8> = raw_save_data
        .iter()
        .map(|b| b ^ 11)
        .filter(|&b| b != 0u8)
        .collect();
    let data_post_b64 = URL_SAFE.decode(data_post_xor).unwrap();
    let mut decoder = GzDecoder::<&[u8]>::new(data_post_b64.as_ref());
    let mut plist = String::new();
    if let Err(_) = decoder.read_to_string(&mut plist) {
        println!("Warning: Game save likely corrupted (gzip decode failed)");
    }
    Value::from_reader(Cursor::new(plist)).unwrap()
}