//! Implements the [SolidityCompiler] trait with solc for
//! compiling contracts to EVM bytecode.

use std::{
    path::PathBuf,
    pin::Pin,
    process::Stdio,
    sync::{Arc, LazyLock},
};

use dashmap::DashMap;
use revive_dt_common::types::VersionOrRequirement;
use revive_dt_config::{SolcConfiguration, WorkingDirectoryConfiguration};
use revive_dt_solc_binaries::download_solc;
use tracing::{Span, field::display, info};

use crate::{CompilerInput, CompilerOutput, ModeOptimizerSetting, ModePipeline, SolidityCompiler};

use anyhow::{Context as _, Result};
use foundry_compilers_artifacts::{
    output_selection::{
        BytecodeOutputSelection, ContractOutputSelection, EvmOutputSelection, OutputSelection,
    },
    solc::CompilerOutput as SolcOutput,
    solc::*,
};
use semver::Version;
use tokio::{io::AsyncWriteExt, process::Command as AsyncCommand};

#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct Solc(Arc<SolcInner>);

#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
struct SolcInner {
    /// The path of the solidity compiler executable that this object uses.
    solc_path: PathBuf,
    /// The version of the solidity compiler executable that this object uses.
    solc_version: Version,
}

impl Solc {
    pub async fn new(
        context: impl AsRef<SolcConfiguration> + AsRef<WorkingDirectoryConfiguration>,
        version: impl Into<Option<VersionOrRequirement>>,
    ) -> Result<Self> {
        // This is a cache for the compiler objects so that whenever the same compiler version is
        // requested the same object is returned. We do this as we do not want to keep cloning the
        // compiler around.
        static COMPILERS_CACHE: LazyLock<DashMap<(PathBuf, Version), Solc>> =
            LazyLock::new(Default::default);

        let working_directory_configuration =
            AsRef::<WorkingDirectoryConfiguration>::as_ref(&context);
        let solc_configuration = AsRef::<SolcConfiguration>::as_ref(&context);

        // We attempt to download the solc binary. Note the following: this call does the version
        // resolution for us. Therefore, even if the download didn't proceed, this function will
        // resolve the version requirement into a canonical version of the compiler. It's then up
        // to us to either use the provided path or not.
        let version = version
            .into()
            .unwrap_or_else(|| solc_configuration.version.clone().into());
        let (version, path) =
            download_solc(working_directory_configuration.as_path(), version, false)
                .await
                .context("Failed to download/get path to solc binary")?;

        Ok(COMPILERS_CACHE
            .entry((path.clone(), version.clone()))
            .or_insert_with(|| {
                info!(
                    solc_path = %path.display(),
                    solc_version = %version,
                    "Created a new solc compiler object"
                );
                Self(Arc::new(SolcInner {
                    solc_path: path,
                    solc_version: version,
                }))
            })
            .clone())
    }
}

impl SolidityCompiler for Solc {
    fn version(&self) -> &Version {
        &self.0.solc_version
    }

    fn path(&self) -> &std::path::Path {
        &self.0.solc_path
    }

    #[tracing::instrument(level = "debug", ret)]
    #[tracing::instrument(
        level = "error",
        skip_all,
        fields(json_in = tracing::field::Empty),
        err(Debug)
    )]
    fn build(
        &self,
        CompilerInput {
            pipeline,
            optimization,
            evm_version,
            allow_paths,
            base_path,
            sources,
            libraries,
            revert_string_handling,
        }: CompilerInput,
    ) -> Pin<Box<dyn Future<Output = Result<CompilerOutput>> + '_>> {
        Box::pin(async move {
            // Be careful to entirely omit the viaIR field if the compiler does not support it,
            // as it will error if you provide fields it does not know about. Because
            // `supports_mode` is called prior to instantiating a compiler, we should never
            // ask for something which is invalid.
            let via_ir = match (pipeline, self.compiler_supports_yul()) {
                (pipeline, true) => pipeline.map(|p| p.via_yul_ir()),
                (_pipeline, false) => None,
            };

            let input = SolcInput {
                language: SolcLanguage::Solidity,
                sources: Sources(
                    sources
                        .into_iter()
                        .map(|(source_path, source_code)| (source_path, Source::new(source_code)))
                        .collect(),
                ),
                settings: Settings {
                    optimizer: Optimizer {
                        enabled: optimization.map(|o| o.optimizations_enabled()),
                        details: Some(Default::default()),
                        ..Default::default()
                    },
                    output_selection: OutputSelection::common_output_selection(
                        [
                            ContractOutputSelection::Abi,
                            ContractOutputSelection::Evm(EvmOutputSelection::ByteCode(
                                BytecodeOutputSelection::Object,
                            )),
                        ]
                        .into_iter()
                        .map(|item| item.to_string()),
                    ),
                    evm_version: evm_version.map(|version| version.to_string().parse().unwrap()),
                    via_ir,
                    libraries: Libraries {
                        libs: libraries
                            .into_iter()
                            .map(|(file_path, libraries)| {
                                (
                                    file_path,
                                    libraries
                                        .into_iter()
                                        .map(|(library_name, library_address)| {
                                            (library_name, library_address.to_string())
                                        })
                                        .collect(),
                                )
                            })
                            .collect(),
                    },
                    debug: revert_string_handling.map(|revert_string_handling| DebuggingSettings {
                        revert_strings: match revert_string_handling {
                            crate::RevertString::Default => Some(RevertStrings::Default),
                            crate::RevertString::Debug => Some(RevertStrings::Debug),
                            crate::RevertString::Strip => Some(RevertStrings::Strip),
                            crate::RevertString::VerboseDebug => Some(RevertStrings::VerboseDebug),
                        },
                        debug_info: Default::default(),
                    }),
                    ..Default::default()
                },
            };

            Span::current().record("json_in", display(serde_json::to_string(&input).unwrap()));

            let path = &self.0.solc_path;
            let mut command = AsyncCommand::new(path);
            command
                .stdin(Stdio::piped())
                .stdout(Stdio::piped())
                .stderr(Stdio::null())
                .arg("--standard-json");

            if let Some(ref base_path) = base_path {
                command.arg("--base-path").arg(base_path);
            }
            if !allow_paths.is_empty() {
                command.arg("--allow-paths").arg(
                    allow_paths
                        .iter()
                        .map(|path| path.display().to_string())
                        .collect::<Vec<_>>()
                        .join(","),
                );
            }
            let mut child = command
                .spawn()
                .with_context(|| format!("Failed to spawn solc at {}", path.display()))?;

            let stdin = child.stdin.as_mut().expect("should be piped");
            let serialized_input = serde_json::to_vec(&input)
                .context("Failed to serialize Standard JSON input for solc")?;
            stdin
                .write_all(&serialized_input)
                .await
                .context("Failed to write Standard JSON to solc stdin")?;
            let output = child
                .wait_with_output()
                .await
                .context("Failed while waiting for solc process to finish")?;

            if !output.status.success() {
                let json_in = serde_json::to_string_pretty(&input)
                    .context("Failed to pretty-print Standard JSON input for logging")?;
                tracing::error!(
                    status = %output.status,
                    json_input = json_in,
                    "Compilation using solc failed"
                );
                anyhow::bail!("Compilation failed");
            }

            let parsed = serde_json::from_slice::<SolcOutput>(&output.stdout)
                .map_err(|e| {
                    anyhow::anyhow!(
                        "failed to parse resolc JSON output: {e}\nstdout: {}",
                        String::from_utf8_lossy(&output.stdout)
                    )
                })
                .context("Failed to parse solc standard JSON output")?;

            // Detecting if the compiler output contained errors and reporting them through logs and
            // errors instead of returning the compiler output that might contain errors.
            for error in parsed.errors.iter() {
                if error.severity == Severity::Error {
                    tracing::error!(?error, ?input, "Encountered an error in the compilation");
                    anyhow::bail!("Encountered an error in the compilation: {error}")
                }
            }

            tracing::debug!(
                output = %String::from_utf8_lossy(&output.stdout).to_string(),
                "Compiled successfully"
            );

            let mut compiler_output = CompilerOutput::default();
            for (contract_path, contracts) in parsed.contracts {
                let map = compiler_output
                    .contracts
                    .entry(contract_path.canonicalize().with_context(|| {
                        format!(
                            "Failed to canonicalize contract path {}",
                            contract_path.display()
                        )
                    })?)
                    .or_default();
                for (contract_name, contract_info) in contracts.into_iter() {
                    let source_code = contract_info
                        .evm
                        .and_then(|evm| evm.bytecode)
                        .map(|bytecode| match bytecode.object {
                            BytecodeObject::Bytecode(bytecode) => bytecode.to_string(),
                            BytecodeObject::Unlinked(unlinked) => unlinked,
                        })
                        .context("Unexpected - contract compiled with solc has no source code")?;
                    let abi = contract_info
                        .abi
                        .context("Unexpected - contract compiled with solc as no ABI")?;
                    map.insert(contract_name, (source_code, abi));
                }
            }

            Ok(compiler_output)
        })
    }

    fn supports_mode(
        &self,
        _optimize_setting: ModeOptimizerSetting,
        pipeline: ModePipeline,
    ) -> bool {
        // solc 0.8.13 and above supports --via-ir, and less than that does not. Thus, we support mode E
        // (ie no Yul IR) in either case, but only support Y (via Yul IR) if the compiler is new enough.
        pipeline == ModePipeline::ViaEVMAssembly
            || (pipeline == ModePipeline::ViaYulIR && self.compiler_supports_yul())
    }
}

impl Solc {
    fn compiler_supports_yul(&self) -> bool {
        const SOLC_VERSION_SUPPORTING_VIA_YUL_IR: Version = Version::new(0, 8, 13);
        SolidityCompiler::version(self) >= &SOLC_VERSION_SUPPORTING_VIA_YUL_IR
    }
}