use clap::{Arg, ArgAction, ArgMatches, Command};
use eth2::lighthouse_vc::types::SingleKeystoreResponse;
use eth2::SensitiveUrl;
use serde::{Deserialize, Serialize};
use std::path::PathBuf;

use crate::{common::vc_http_client, DumpConfig};

pub const CMD: &str = "list";
pub const VC_URL_FLAG: &str = "vc-url";
pub const VC_TOKEN_FLAG: &str = "vc-token";

pub fn cli_app() -> Command {
    Command::new(CMD)
        .about("Lists all validators in a validator client using the HTTP API.")
        .arg(
            Arg::new(VC_URL_FLAG)
                .long(VC_URL_FLAG)
                .value_name("HTTP_ADDRESS")
                .help("A HTTP(S) address of a validator client using the keymanager-API.")
                .default_value("http://localhost:5062")
                .requires(VC_TOKEN_FLAG)
                .action(ArgAction::Set)
                .display_order(0),
        )
        .arg(
            Arg::new(VC_TOKEN_FLAG)
                .long(VC_TOKEN_FLAG)
                .value_name("PATH")
                .help("The file containing a token required by the validator client.")
                .action(ArgAction::Set)
                .display_order(0),
        )
}

#[derive(Clone, PartialEq, Debug, Serialize, Deserialize)]
pub struct ListConfig {
    pub vc_url: SensitiveUrl,
    pub vc_token_path: PathBuf,
}

impl ListConfig {
    fn from_cli(matches: &ArgMatches) -> Result<Self, String> {
        Ok(Self {
            vc_token_path: clap_utils::parse_required(matches, VC_TOKEN_FLAG)?,
            vc_url: clap_utils::parse_required(matches, VC_URL_FLAG)?,
        })
    }
}

pub async fn cli_run(matches: &ArgMatches, dump_config: DumpConfig) -> Result<(), String> {
    let config = ListConfig::from_cli(matches)?;
    if dump_config.should_exit_early(&config)? {
        Ok(())
    } else {
        run(config).await?;
        Ok(())
    }
}

async fn run(config: ListConfig) -> Result<Vec<SingleKeystoreResponse>, String> {
    let ListConfig {
        vc_url,
        vc_token_path,
    } = config;

    let (_, validators) = vc_http_client(vc_url.clone(), &vc_token_path).await?;

    println!("List of validators ({}):", validators.len());

    for validator in &validators {
        println!("{}", validator.validating_pubkey);
    }

    Ok(validators)
}

#[cfg(not(debug_assertions))]
#[cfg(test)]
mod test {
    use std::{
        fs::{self, File},
        io::Write,
    };

    use super::*;
    use crate::{
        common::ValidatorSpecification, import_validators::tests::TestBuilder as ImportTestBuilder,
    };
    use validator_http_api::{test_utils::ApiTester, Config as HttpConfig};

    struct TestBuilder {
        list_config: Option<ListConfig>,
        src_import_builder: Option<ImportTestBuilder>,
        http_config: HttpConfig,
        vc_token: Option<String>,
        validators: Vec<ValidatorSpecification>,
    }

    impl TestBuilder {
        async fn new() -> Self {
            Self {
                list_config: None,
                src_import_builder: None,
                http_config: ApiTester::default_http_config(),
                vc_token: None,
                validators: vec![],
            }
        }

        async fn with_validators(mut self, count: u32, first_index: u32) -> Self {
            let builder = ImportTestBuilder::new_with_http_config(self.http_config.clone())
                .await
                .create_validators(count, first_index)
                .await;
            self.list_config = Some(ListConfig {
                vc_url: builder.get_import_config().vc_url,
                vc_token_path: builder.get_import_config().vc_token_path,
            });

            self.vc_token =
                Some(fs::read_to_string(builder.get_import_config().vc_token_path).unwrap());

            let local_validators: Vec<ValidatorSpecification> = {
                let contents =
                    fs::read_to_string(builder.get_import_config().validators_file_path.unwrap())
                        .unwrap();
                serde_json::from_str(&contents).unwrap()
            };

            self.validators = local_validators.clone();
            self.src_import_builder = Some(builder);
            self
        }

        pub async fn run_test(self) -> TestResult {
            let import_test_result = self.src_import_builder.unwrap().run_test().await;
            assert!(import_test_result.result.is_ok());

            let path = self.list_config.clone().unwrap().vc_token_path;
            let parent = path.parent().unwrap();

            fs::create_dir_all(parent).expect("Was not able to create parent directory");

            File::options()
                .write(true)
                .read(true)
                .create(true)
                .truncate(true)
                .open(path)
                .unwrap()
                .write_all(self.vc_token.clone().unwrap().as_bytes())
                .unwrap();

            let result = run(self.list_config.clone().unwrap()).await;

            if result.is_ok() {
                let result_ref = result.as_ref().unwrap();

                for local_validator in &self.validators {
                    let local_keystore = &local_validator.voting_keystore.0;
                    let local_pubkey = local_keystore.public_key().unwrap();
                    assert!(
                        result_ref
                            .iter()
                            .any(|validator| validator.validating_pubkey
                                == local_pubkey.clone().into()),
                        "local validator pubkey not found in result"
                    );
                }

                return TestResult { result: Ok(()) };
            }

            TestResult {
                result: Err(result.unwrap_err()),
            }
        }
    }

    #[must_use] // Use the `assert_ok` or `assert_err` fns to "use" this value.
    struct TestResult {
        result: Result<(), String>,
    }

    impl TestResult {
        fn assert_ok(self) {
            assert_eq!(self.result, Ok(()))
        }
    }
    #[tokio::test]
    async fn list_all_validators() {
        TestBuilder::new()
            .await
            .with_validators(3, 0)
            .await
            .run_test()
            .await
            .assert_ok();
    }
}