use crate::{
    artifacts::{CompactContractRef, Settings},
    cache::SOLIDITY_FILES_CACHE_FILENAME,
    error::Result,
    CompilerOutput, Solc,
};
use serde::{Deserialize, Serialize};
use std::{
    fmt, fs, io,
    path::{Path, PathBuf},
};

/// Where to find all files or where to write them
#[derive(Debug, Clone)]
pub struct ProjectPathsConfig {
    /// Project root
    pub root: PathBuf,
    /// Path to the cache, if any
    pub cache: PathBuf,
    /// Where to store build artifacts
    pub artifacts: PathBuf,
    /// Where to find sources
    pub sources: PathBuf,
    /// Where to find tests
    pub tests: PathBuf,
    /// Where to look for libraries
    pub libraries: Vec<PathBuf>,
}

impl ProjectPathsConfig {
    pub fn builder() -> ProjectPathsConfigBuilder {
        ProjectPathsConfigBuilder::default()
    }

    /// Creates a new hardhat style config instance which points to the canonicalized root path
    pub fn hardhat(root: impl AsRef<Path>) -> io::Result<Self> {
        PathStyle::HardHat.paths(root)
    }

    /// Creates a new dapptools style config instance which points to the canonicalized root path
    pub fn dapptools(root: impl AsRef<Path>) -> io::Result<Self> {
        PathStyle::Dapptools.paths(root)
    }

    /// Creates a new config with the current directory as the root
    pub fn current_hardhat() -> io::Result<Self> {
        Self::hardhat(std::env::current_dir()?)
    }

    /// Creates a new config with the current directory as the root
    pub fn current_dapptools() -> io::Result<Self> {
        Self::dapptools(std::env::current_dir()?)
    }
}

#[derive(Debug, Clone, Eq, PartialEq)]
pub enum PathStyle {
    HardHat,
    Dapptools,
}

impl PathStyle {
    pub fn paths(&self, root: impl AsRef<Path>) -> io::Result<ProjectPathsConfig> {
        let root = std::fs::canonicalize(root)?;

        match self {
            PathStyle::Dapptools => ProjectPathsConfig::builder()
                .sources(root.join("src"))
                .artifacts(root.join("out"))
                .lib(root.join("lib"))
                .root(root)
                .build(),
            PathStyle::HardHat => ProjectPathsConfig::builder()
                .sources(root.join("contracts"))
                .artifacts(root.join("artifacts"))
                .lib(root.join("node_modules"))
                .root(root)
                .build(),
        }
    }
}

#[derive(Debug, Clone, Default)]
pub struct ProjectPathsConfigBuilder {
    root: Option<PathBuf>,
    cache: Option<PathBuf>,
    artifacts: Option<PathBuf>,
    sources: Option<PathBuf>,
    tests: Option<PathBuf>,
    libraries: Option<Vec<PathBuf>>,
}

impl ProjectPathsConfigBuilder {
    pub fn root(mut self, root: impl Into<PathBuf>) -> Self {
        self.root = Some(root.into());
        self
    }

    pub fn cache(mut self, cache: impl Into<PathBuf>) -> Self {
        self.cache = Some(cache.into());
        self
    }

    pub fn artifacts(mut self, artifacts: impl Into<PathBuf>) -> Self {
        self.artifacts = Some(artifacts.into());
        self
    }

    pub fn sources(mut self, sources: impl Into<PathBuf>) -> Self {
        self.sources = Some(sources.into());
        self
    }

    pub fn tests(mut self, tests: impl Into<PathBuf>) -> Self {
        self.tests = Some(tests.into());
        self
    }

    /// Specifically disallow additional libraries
    pub fn no_libs(mut self) -> Self {
        self.libraries = Some(Vec::new());
        self
    }

    pub fn lib(mut self, lib: impl Into<PathBuf>) -> Self {
        self.libraries.get_or_insert_with(Vec::new).push(lib.into());
        self
    }

    pub fn libs(mut self, libs: impl IntoIterator<Item = impl Into<PathBuf>>) -> Self {
        let libraries = self.libraries.get_or_insert_with(Vec::new);
        for lib in libs.into_iter() {
            libraries.push(lib.into());
        }
        self
    }

    pub fn build(self) -> io::Result<ProjectPathsConfig> {
        let root = self.root.map(Ok).unwrap_or_else(std::env::current_dir)?;
        let root = std::fs::canonicalize(root)?;

        Ok(ProjectPathsConfig {
            cache: self
                .cache
                .unwrap_or_else(|| root.join("cache").join(SOLIDITY_FILES_CACHE_FILENAME)),
            artifacts: self.artifacts.unwrap_or_else(|| root.join("artifacts")),
            sources: self.sources.unwrap_or_else(|| root.join("contracts")),
            tests: self.tests.unwrap_or_else(|| root.join("tests")),
            libraries: self.libraries.unwrap_or_default(),
            root,
        })
    }
}

/// The config to use when compiling the contracts
#[derive(Clone, Debug, Eq, PartialEq, Serialize, Deserialize)]
pub struct SolcConfig {
    /// Configured solc version
    pub version: String,
    /// How the file was compiled
    pub settings: Settings,
}

impl SolcConfig {
    /// # Example
    ///
    /// Autodetect solc version and default settings
    ///
    /// ```rust
    /// use ethers_solc::SolcConfig;
    /// let config = SolcConfig::builder().build().unwrap();
    /// ```
    pub fn builder() -> SolcConfigBuilder {
        SolcConfigBuilder::default()
    }
}

#[derive(Default)]
pub struct SolcConfigBuilder {
    version: Option<String>,
    settings: Option<Settings>,
}

impl SolcConfigBuilder {
    pub fn version(mut self, version: impl Into<String>) -> Self {
        self.version = Some(version.into());
        self
    }

    pub fn settings(mut self, settings: Settings) -> Self {
        self.settings = Some(settings);
        self
    }

    /// Creates the solc config
    ///
    /// If no solc version is configured then it will be determined by calling `solc --version`.
    pub fn build(self) -> Result<SolcConfig> {
        let Self { version, settings } = self;
        let version =
            version.map(Ok).unwrap_or_else(|| Solc::default().version().map(|s| s.to_string()))?;
        let settings = settings.unwrap_or_default();
        Ok(SolcConfig { version, settings })
    }
}

/// Determines how to handle compiler output
pub enum ArtifactOutput {
    /// No-op, does not write the artifacts to disk.
    Nothing,
    /// Creates a single json artifact with
    /// ```json
    ///  {
    ///    "abi": [],
    ///    "bin": "...",
    ///    "runtime-bin": "..."
    ///  }
    /// ```
    MinimalCombined,
    /// Hardhat style artifacts
    Hardhat,
    /// Custom output handler
    Custom(Box<dyn Fn(&CompilerOutput, &ProjectPathsConfig) -> Result<()>>),
}

impl ArtifactOutput {
    /// Is expected to handle the output and where to store it
    pub fn on_output(&self, output: &CompilerOutput, layout: &ProjectPathsConfig) -> Result<()> {
        match self {
            ArtifactOutput::Nothing => Ok(()),
            ArtifactOutput::MinimalCombined => {
                fs::create_dir_all(&layout.artifacts)?;

                for contracts in output.contracts.values() {
                    for (name, contract) in contracts {
                        let file = layout.artifacts.join(format!("{}.json", name));
                        let min = CompactContractRef::from(contract);
                        fs::write(file, serde_json::to_vec_pretty(&min)?)?
                    }
                }
                Ok(())
            }
            ArtifactOutput::Hardhat => {
                todo!("Hardhat style artifacts not yet implemented")
            }
            ArtifactOutput::Custom(f) => f(output, layout),
        }
    }
}

impl Default for ArtifactOutput {
    fn default() -> Self {
        ArtifactOutput::MinimalCombined
    }
}

impl fmt::Debug for ArtifactOutput {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            ArtifactOutput::Nothing => {
                write!(f, "Nothing")
            }
            ArtifactOutput::MinimalCombined => {
                write!(f, "MinimalCombined")
            }
            ArtifactOutput::Hardhat => {
                write!(f, "Hardhat")
            }
            ArtifactOutput::Custom(_) => {
                write!(f, "Custom")
            }
        }
    }
}