use figment::{providers::Serialized, value, Figment, Metadata, Profile, Provider};
use serde::{Deserialize, Deserializer, Serialize};
use std::{convert::Infallible, path::PathBuf, str::FromStr};

#[derive(Debug, PartialEq, Eq, Clone, Default, Serialize, Deserialize)]
pub struct Config {
    pub(crate) paths: Vec<PathEntry>,
}

impl Config {
    // Extract the configuration from any `Provider`
    pub fn extract<T: Provider>(provider: T) -> figment::error::Result<Config> {
        Figment::from(provider).extract()
    }

    // Provide a default provider, a `Figment`.
    pub fn figment() -> Figment {
        Figment::from(Config::default())
    }
}

impl Provider for Config {
    fn metadata(&self) -> Metadata {
        Metadata::named("Tmuxr path config")
    }

    fn data(&self) -> figment::error::Result<value::Map<Profile, value::Dict>> {
        Serialized::defaults(self).data()
    }
}

#[derive(Debug, PartialEq, Eq, Clone, Default, Serialize)]
pub struct PathEntry {
    pub path: PathBuf,
    pub hidden: bool,
    pub recurse: Option<usize>,
}

impl From<PathBuf> for PathEntry {
    fn from(path: PathBuf) -> Self {
        Self {
            path,
            ..Default::default()
        }
    }
}

impl FromStr for PathEntry {
    type Err = Infallible;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        s.parse().map(PathBuf::into)
    }
}

impl<'de> Deserialize<'de> for PathEntry {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        #[derive(Deserialize)]
        #[serde(untagged)]
        enum Variants {
            String(String),
            Struct {
                path: PathBuf,
                #[serde(default)]
                hidden: bool,
                #[serde(default)]
                recurse: Option<usize>,
            },
        }

        match Variants::deserialize(deserializer)? {
            Variants::String(s) => s.parse().map_err(serde::de::Error::custom),
            Variants::Struct {
                path,
                hidden,
                recurse,
            } => Ok(Self {
                path,
                hidden,
                recurse,
            }),
        }
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use figment::providers::{Format, Serialized, Toml};

    #[test]
    fn test_extract() {
        figment::Jail::expect_with(|jail| {
            jail.create_file(
                "tmuxr.toml",
                r#"
                paths = [
                    "/path/to/projects",
                    { path = "/path/to/other_projects", recurse = 1, hidden = true },
                    { path = "/path/to/another_project", recurse = 0 },
                ]
                "#,
            )?;

            let config: Config = Figment::from(Serialized::defaults(Config::default()))
                .merge(Toml::file("tmuxr.toml"))
                .extract()?;

            assert_eq!(
                config,
                Config {
                    paths: Vec::from([
                        PathEntry {
                            path: "/path/to/projects".into(),
                            hidden: false,
                            recurse: None,
                        },
                        PathEntry {
                            path: "/path/to/other_projects".into(),
                            hidden: true,
                            recurse: Some(1),
                        },
                        PathEntry {
                            path: "/path/to/another_project".into(),
                            hidden: false,
                            recurse: Some(0),
                        },
                    ]),
                }
            );

            Ok(())
        });
    }
}