use std::collections::HashMap;
use std::path::{Path, PathBuf};
use std::sync::{RwLock, RwLockReadGuard};
use std::{fs, process};

use cursive::theme::Theme;
use platform_dirs::AppDirs;

pub const CLIENT_ID: &str = "d420a117a32841c2b3474932e49fb54b";

#[derive(Clone, Serialize, Deserialize, Debug, Default)]
pub struct ConfigValues {
    pub default_keybindings: Option<bool>,
    pub keybindings: Option<HashMap<String, String>>,
    pub theme: Option<ConfigTheme>,
    pub use_nerdfont: Option<bool>,
    pub saved_state: Option<SavedState>,
    pub audio_cache: Option<bool>,
    pub backend: Option<String>,
    pub backend_device: Option<String>,
    pub volnorm: Option<bool>,
    pub volnorm_pregain: Option<f32>,
    pub notify: Option<bool>,
    pub bitrate: Option<u32>,
    pub album_column: Option<bool>,
}

#[derive(Serialize, Deserialize, Debug, Default, Clone)]
pub struct SavedState {
    pub volume: Option<u8>,
    pub shuffle: Option<bool>,
    pub repeat: Option<String>,
}

#[derive(Serialize, Deserialize, Debug, Default, Clone)]
pub struct ConfigTheme {
    pub background: Option<String>,
    pub primary: Option<String>,
    pub secondary: Option<String>,
    pub title: Option<String>,
    pub playing: Option<String>,
    pub playing_selected: Option<String>,
    pub playing_bg: Option<String>,
    pub highlight: Option<String>,
    pub highlight_bg: Option<String>,
    pub error: Option<String>,
    pub error_bg: Option<String>,
    pub statusbar_progress: Option<String>,
    pub statusbar_progress_bg: Option<String>,
    pub statusbar: Option<String>,
    pub statusbar_bg: Option<String>,
    pub cmdline: Option<String>,
    pub cmdline_bg: Option<String>,
    pub search_match: Option<String>,
}

lazy_static! {
    pub static ref BASE_PATH: RwLock<Option<PathBuf>> = RwLock::new(None);
}

pub struct Config {
    values: RwLock<ConfigValues>,
}

impl Config {
    pub fn new() -> Self {
        let values = load().unwrap_or_else(|e| {
            eprintln!("could not load config: {}", e);
            process::exit(1);
        });

        Self {
            values: RwLock::new(values),
        }
    }

    pub fn values(&self) -> RwLockReadGuard<ConfigValues> {
        self.values.read().expect("can't readlock config values")
    }

    pub fn build_theme(&self) -> Theme {
        let theme = &self.values().theme;
        crate::theme::load(theme)
    }

    pub fn reload(&self) {
        let cfg = load().expect("could not reload config");
        *self.values.write().expect("can't writelock config values") = cfg
    }
}

fn load() -> Result<ConfigValues, String> {
    let path = config_path("config.toml");
    load_or_generate_default(path, |_| Ok(ConfigValues::default()), false)
}

fn proj_dirs() -> AppDirs {
    match *BASE_PATH.read().expect("can't readlock BASE_PATH") {
        Some(ref basepath) => AppDirs {
            cache_dir: basepath.join(".cache"),
            config_dir: basepath.join(".config"),
            data_dir: basepath.join(".local/share"),
            state_dir: basepath.join(".local/state"),
        },
        None => AppDirs::new(Some("ncspot"), true).expect("can't determine project paths"),
    }
}

pub fn config_path(file: &str) -> PathBuf {
    let proj_dirs = proj_dirs();
    let cfg_dir = &proj_dirs.config_dir;
    trace!("{:?}", cfg_dir);
    if cfg_dir.exists() && !cfg_dir.is_dir() {
        fs::remove_file(cfg_dir).expect("unable to remove old config file");
    }
    if !cfg_dir.exists() {
        fs::create_dir_all(cfg_dir).expect("can't create config folder");
    }
    let mut cfg = cfg_dir.to_path_buf();
    cfg.push(file);
    cfg
}

pub fn cache_path(file: &str) -> PathBuf {
    let proj_dirs = proj_dirs();
    let cache_dir = &proj_dirs.cache_dir;
    if !cache_dir.exists() {
        fs::create_dir_all(cache_dir).expect("can't create cache folder");
    }
    let mut pb = cache_dir.to_path_buf();
    pb.push(file);
    pb
}

/// Configuration and credential file helper
/// Creates a default configuration if none exist, otherwise will optionally overwrite
/// the file if it fails to parse
pub fn load_or_generate_default<
    P: AsRef<Path>,
    T: serde::Serialize + serde::de::DeserializeOwned,
    F: Fn(&Path) -> Result<T, String>,
>(
    path: P,
    default: F,
    default_on_parse_failure: bool,
) -> Result<T, String> {
    let path = path.as_ref();
    // Nothing exists so just write the default and return it
    if !path.exists() {
        let value = default(&path)?;
        return write_content_helper(&path, value);
    }

    // load the serialized content. Always report this failure
    let contents = std::fs::read_to_string(&path)
        .map_err(|e| format!("Unable to read {}: {}", path.to_string_lossy(), e))?;

    // Deserialize the content, optionally fall back to default if it fails
    let result = toml::from_str(&contents);
    if default_on_parse_failure && result.is_err() {
        let value = default(&path)?;
        return write_content_helper(&path, value);
    }
    result.map_err(|e| format!("Unable to parse {}: {}", path.to_string_lossy(), e))
}

fn write_content_helper<P: AsRef<Path>, T: serde::Serialize>(
    path: P,
    value: T,
) -> Result<T, String> {
    let content =
        toml::to_string_pretty(&value).map_err(|e| format!("Failed serializing value: {}", e))?;
    fs::write(path.as_ref(), content)
        .map(|_| value)
        .map_err(|e| {
            format!(
                "Failed writing content to {}: {}",
                path.as_ref().display(),
                e
            )
        })
}