use std::path::{Path, PathBuf};

extern crate fxhash;
use fxhash::FxHashMap;
use iced::Theme;
use rust_format::{Edition, Formatter, RustFmt};
use serde::{Deserialize, Serialize};

use super::rendered_element::RenderedElement;
use crate::Error;
use crate::config::Config;
use crate::theme::{theme_from_str, theme_index, theme_to_string};

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Project {
    pub title: Option<String>,
    pub theme: Option<String>,
    pub element_tree: Option<RenderedElement>,
    #[serde(skip)]
    theme_cache: FxHashMap<String, String>,
}

impl Default for Project {
    fn default() -> Self {
        Self::new()
    }
}

impl Project {
    pub fn new() -> Self {
        Self {
            title: None,
            theme: None,
            element_tree: None,
            theme_cache: FxHashMap::default(),
        }
    }

    pub fn get_theme(&self, config: &Config) -> Theme {
        match &self.theme {
            Some(theme) => theme_from_str(Some(config), theme),
            None => Theme::default(),
        }
    }

    fn theme_code(&mut self, theme: &Theme) -> String {
        let theme_name = theme.to_string();
        if theme_index(&theme_name, Theme::ALL).is_none() {
            (*self
                .theme_cache
                .entry(theme_name)
                .or_insert(theme_to_string(theme)))
            .to_string()
        } else {
            theme_name.replace(" ", "")
        }
    }

    pub async fn from_path(
        path: PathBuf,
        config: Config,
    ) -> Result<(PathBuf, Self), Error> {
        let contents = tokio::fs::read_to_string(&path).await?;
        let mut project: Self = serde_json::from_str(&contents)?;

        let _ = project.theme_code(&project.get_theme(&config));

        Ok((path, project))
    }

    pub async fn from_file(config: Config) -> Result<(PathBuf, Self), Error> {
        let picked_file = rfd::AsyncFileDialog::new()
            .set_title("Open a JSON file...")
            .add_filter("*.json, *.JSON", &["json", "JSON"])
            .pick_file()
            .await
            .ok_or(Error::DialogClosed)?;

        let path = picked_file.path().to_owned();

        Self::from_path(path, config).await
    }

    pub async fn write_to_file(
        self,
        path: Option<PathBuf>,
    ) -> Result<PathBuf, Error> {
        let path = if let Some(p) = path {
            p
        } else {
            rfd::AsyncFileDialog::new()
                .set_title("Save to JSON file...")
                .add_filter("*.json, *.JSON", &["json", "JSON"])
                .save_file()
                .await
                .as_ref()
                .map(rfd::FileHandle::path)
                .map(Path::to_owned)
                .ok_or(Error::DialogClosed)?
        };

        let contents = serde_json::to_string(&self)?;
        tokio::fs::write(&path, contents).await?;

        Ok(path)
    }

    pub fn app_code(&mut self, config: &Config) -> Result<String, Error> {
        match self.element_tree {
            Some(ref element_tree) => {
                let (imports, view) = element_tree.codegen();
                let theme = self.get_theme(config);
                let theme_code = self.theme_code(&theme);
                let mut theme_imports = "";
                if theme_index(&theme.to_string(), Theme::ALL).is_none() {
                    if theme_code.contains("Extended") {
                        theme_imports = "use iced::{{color,theme::{{Palette,palette::{{Extended,Background,Primary,Secondary,Success,Danger,Warning,Pair}}}}}};\n";
                    } else {
                        theme_imports = "use iced::{{color,theme::Palette}};\n";
                    }
                }

                let app_code = format!(
                    r#"// Automatically generated by iced Builder
use iced::{{widget::{{{imports}}},Element}};
{theme_imports}

fn main() -> iced::Result {{
    iced::application("{}", State::update, State::view).theme(State::theme).run()
}}

#[derive(Default)]
struct State;

#[derive(Debug, Clone)]
enum Message {{}}

impl State {{
    fn update(&mut self, _message: Message) {{}}

    fn theme(&self) -> iced::Theme {{
        iced::Theme::{}
    }}

    fn view(&self) -> Element<Message> {{
        {view}.into()
    }}
}}"#,
                    match self.title {
                        Some(ref t) => t,
                        None => "New app",
                    },
                    theme_code
                );
                let config = rust_format::Config::new_str()
                    .edition(Edition::Rust2021)
                    .option("trailing_comma", "Never")
                    .option("imports_granularity", "Crate");
                let rustfmt = RustFmt::from_config(config);
                Ok(rustfmt.format_str(app_code)?)
            }
            None => Err("No element tree present".into()),
        }
    }
}