use bat_adapters::official::yostar_jp::PatchPlatform;
use bat_infrastructure::{
    OfficialServerInfoSource, OfficialUpdateConfig, OfficialUpdateService, OfficialUpdateStatus,
};
use serde::Serialize;
use std::env;
use std::path::PathBuf;
use std::thread;
use std::time::Duration;

const EXIT_ERROR: i32 = 1;
const EXIT_LOCKED: i32 = 75;
const DEFAULT_WATCH_INTERVAL_SECONDS: u64 = 60 * 60;
const DEFAULT_ERROR_RETRY_SECONDS: u64 = 60;

fn main() {
    match run() {
        Ok(()) => {}
        Err(error) => {
            let exit_code = if error.to_string().contains("locked") {
                EXIT_LOCKED
            } else {
                EXIT_ERROR
            };
            let payload = ErrorReport {
                status: "error",
                exit_code,
                error: error.to_string(),
                next_retry_seconds: None,
            };
            eprintln!(
                "{}",
                serde_json::to_string_pretty(&payload)
                    .unwrap_or_else(|_| "{\"status\":\"error\"}".to_string())
            );
            std::process::exit(exit_code);
        }
    }
}

fn run() -> anyhow::Result<()> {
    let options = parse_args()?;
    if options.watch {
        run_watch(options)?;
    } else {
        let report = OfficialUpdateService::new().run(&options.config)?;
        if should_print_status(report.update_status, options.quiet_up_to_date) {
            println!("{}", serde_json::to_string_pretty(&report)?);
        }
    }
    Ok(())
}

#[derive(Debug, Serialize)]
struct ErrorReport<'a> {
    status: &'a str,
    exit_code: i32,
    error: String,
    #[serde(skip_serializing_if = "Option::is_none")]
    next_retry_seconds: Option<u64>,
}

#[derive(Debug, Clone, PartialEq, Eq)]
struct CliOptions {
    config: OfficialUpdateConfig,
    watch: bool,
    interval: Duration,
    error_retry_interval: Duration,
    quiet_up_to_date: bool,
    quiet_up_to_date_explicit: bool,
}

impl Default for CliOptions {
    fn default() -> Self {
        Self {
            config: OfficialUpdateConfig::default(),
            watch: false,
            interval: Duration::from_secs(DEFAULT_WATCH_INTERVAL_SECONDS),
            error_retry_interval: Duration::from_secs(DEFAULT_ERROR_RETRY_SECONDS),
            quiet_up_to_date: false,
            quiet_up_to_date_explicit: false,
        }
    }
}

fn run_watch(options: CliOptions) -> anyhow::Result<()> {
    if options.config.dry_run {
        return Err(anyhow::anyhow!("watch mode cannot be used with --dry-run"));
    }
    if options.interval.is_zero() {
        return Err(anyhow::anyhow!("watch interval must be greater than zero"));
    }
    if options.error_retry_interval.is_zero() {
        return Err(anyhow::anyhow!(
            "watch error retry interval must be greater than zero"
        ));
    }
    let service = OfficialUpdateService::new();
    loop {
        let mut sleep_for = options.interval;
        match service.run(&options.config) {
            Ok(report) => {
                if should_print_status(report.update_status, options.quiet_up_to_date) {
                    println!("{}", serde_json::to_string_pretty(&report)?);
                }
            }
            Err(error) => {
                sleep_for = options.error_retry_interval;
                let payload = ErrorReport {
                    status: "error",
                    exit_code: EXIT_ERROR,
                    error: error.to_string(),
                    next_retry_seconds: Some(sleep_for.as_secs()),
                };
                eprintln!("{}", serde_json::to_string_pretty(&payload)?);
            }
        }

        thread::sleep(sleep_for);
    }
}

fn should_print_status(status: OfficialUpdateStatus, quiet_up_to_date: bool) -> bool {
    !(quiet_up_to_date && status == OfficialUpdateStatus::UpToDate)
}

fn parse_args() -> anyhow::Result<CliOptions> {
    parse_args_from(env::args())
}

fn parse_args_from(raw_args: impl IntoIterator<Item = String>) -> anyhow::Result<CliOptions> {
    let mut args = raw_args.into_iter();
    let binary = args
        .next()
        .unwrap_or_else(|| "bat-official-sync".to_string());
    let mut options = CliOptions::default();

    while let Some(flag) = args.next() {
        match flag.as_str() {
            "--auto-discover" => {
                options.config.auto_discover = true;
            }
            "--server-info-url" => {
                options.config.server_info_source = Some(OfficialServerInfoSource::OfficialUrl(
                    next_option_value(&mut args, &flag)?,
                ));
            }
            "--server-info-file" => {
                options.config.server_info_source = Some(OfficialServerInfoSource::OfficialFile(
                    next_option_value(&mut args, &flag)?,
                ));
            }
            "--server-info-path" => {
                options.config.server_info_source = Some(OfficialServerInfoSource::LocalPath(
                    PathBuf::from(next_option_value(&mut args, &flag)?),
                ));
            }
            "--connection-group" => {
                options.config.connection_group = Some(next_option_value(&mut args, &flag)?);
            }
            "--app-version" => {
                options.config.app_version = Some(next_option_value(&mut args, &flag)?);
            }
            "--launcher-version" => {
                options.config.launcher_version = next_option_value(&mut args, &flag)?;
            }
            "--platforms" => {
                let value = next_option_value(&mut args, &flag)?;
                options.config.platforms =
                    Some(parse_platforms(&value).map_err(anyhow::Error::msg)?);
            }
            "--output" => {
                options.config.output_root = PathBuf::from(next_option_value(&mut args, &flag)?);
            }
            "--snapshot" => {
                options.config.snapshot_path =
                    Some(PathBuf::from(next_option_value(&mut args, &flag)?));
            }
            "--curl" => {
                options.config.curl_command = PathBuf::from(next_option_value(&mut args, &flag)?);
            }
            "--unzip" => {
                options.config.unzip_command = PathBuf::from(next_option_value(&mut args, &flag)?);
            }
            "--dry-run" => {
                options.config.dry_run = true;
            }
            "--plan" => {
                options.config.plan = true;
            }
            "--force" => {
                options.config.force = true;
            }
            "--audit-local" => {
                options.config.audit_local = true;
            }
            "--no-audit-local" => {
                options.config.audit_local = false;
            }
            "--repair" => {
                options.config.repair = true;
            }
            "--no-repair" => {
                options.config.repair = false;
            }
            "--watch" => {
                options.watch = true;
            }
            "--interval" => {
                options.interval = parse_duration(&next_option_value(&mut args, &flag)?)?;
            }
            "--interval-seconds" => {
                let seconds = next_option_value(&mut args, &flag)?
                    .parse::<u64>()
                    .map_err(|error| anyhow::anyhow!("invalid seconds for {flag}: {error}"))?;
                options.interval = Duration::from_secs(seconds);
            }
            "--error-retry" => {
                options.error_retry_interval =
                    parse_duration(&next_option_value(&mut args, &flag)?)?;
            }
            "--error-retry-seconds" => {
                let seconds = next_option_value(&mut args, &flag)?
                    .parse::<u64>()
                    .map_err(|error| anyhow::anyhow!("invalid seconds for {flag}: {error}"))?;
                options.error_retry_interval = Duration::from_secs(seconds);
            }
            "--quiet-up-to-date" => {
                options.quiet_up_to_date = true;
                options.quiet_up_to_date_explicit = true;
            }
            "--no-quiet-up-to-date" => {
                options.quiet_up_to_date = false;
                options.quiet_up_to_date_explicit = true;
            }
            "--help" | "-h" => {
                print_usage(&binary);
                std::process::exit(0);
            }
            _ => return Err(anyhow::anyhow!("unknown argument: {flag}")),
        }
    }

    if options.watch && options.config.dry_run {
        return Err(anyhow::anyhow!("watch mode cannot be used with --dry-run"));
    }
    if options.interval.is_zero() {
        return Err(anyhow::anyhow!("watch interval must be greater than zero"));
    }
    if options.error_retry_interval.is_zero() {
        return Err(anyhow::anyhow!(
            "watch error retry interval must be greater than zero"
        ));
    }
    if options.watch && !options.quiet_up_to_date_explicit {
        options.quiet_up_to_date = true;
    }

    Ok(options)
}

fn next_option_value(
    args: &mut impl Iterator<Item = String>,
    flag: &str,
) -> anyhow::Result<String> {
    args.next()
        .ok_or_else(|| anyhow::anyhow!("missing value for {flag}"))
}

fn print_usage(binary: &str) {
    eprintln!(
        "usage: {binary} [--auto-discover | --server-info-url <official-url> | --server-info-file <official-json-name> | --server-info-path <local-json>] \
         [--app-version 1.70.0] [--connection-group <name>] [--launcher-version 1.7.2] \
         [--platforms Windows,Android] [--output official_update_output] [--snapshot official-sync-snapshot.json] \
         [--curl curl] [--unzip unzip] [--dry-run] [--plan] [--force] [--audit-local|--no-audit-local] [--repair|--no-repair] \
         [--watch] [--interval 1h|60m|3600s] [--error-retry 60s] [--quiet-up-to-date|--no-quiet-up-to-date]"
    );
}

fn parse_duration(value: &str) -> anyhow::Result<Duration> {
    let value = value.trim();
    if value.is_empty() {
        return Err(anyhow::anyhow!("duration must not be empty"));
    }

    let (number, multiplier) = if let Some(number) = value.strip_suffix("ms") {
        let millis = number
            .parse::<u64>()
            .map_err(|error| anyhow::anyhow!("invalid millisecond duration {value}: {error}"))?;
        return Ok(Duration::from_millis(millis));
    } else if let Some(number) = value.strip_suffix('s') {
        (number, 1)
    } else if let Some(number) = value.strip_suffix('m') {
        (number, 60)
    } else if let Some(number) = value.strip_suffix('h') {
        (number, 60 * 60)
    } else {
        (value, 1)
    };

    let amount = number
        .parse::<u64>()
        .map_err(|error| anyhow::anyhow!("invalid duration {value}: {error}"))?;
    Ok(Duration::from_secs(amount.saturating_mul(multiplier)))
}

fn parse_platforms(value: &str) -> Result<Vec<PatchPlatform>, String> {
    value
        .split(',')
        .map(str::trim)
        .filter(|part| !part.is_empty())
        .map(parse_platform)
        .collect()
}

fn parse_platform(value: &str) -> Result<PatchPlatform, String> {
    match value.to_ascii_lowercase().as_str() {
        "windows" | "win" => Ok(PatchPlatform::Windows),
        "android" => Ok(PatchPlatform::Android),
        _ => Err(format!("unsupported platform: {value}")),
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    fn parse(values: &[&str]) -> anyhow::Result<CliOptions> {
        parse_args_from(values.iter().map(|value| value.to_string()))
    }

    #[test]
    fn parses_auto_discover_sync_args() {
        let options = parse(&[
            "bat-official-sync",
            "--auto-discover",
            "--platforms",
            "Windows,Android",
            "--snapshot",
            "/tmp/snapshot.json",
            "--dry-run",
            "--plan",
        ])
        .unwrap();
        let config = options.config;

        assert!(config.auto_discover);
        assert_eq!(
            config.platforms.as_deref(),
            Some([PatchPlatform::Windows, PatchPlatform::Android].as_slice())
        );
        assert_eq!(
            config.snapshot_path,
            Some(PathBuf::from("/tmp/snapshot.json"))
        );
        assert!(config.dry_run);
        assert!(config.plan);
        assert!(config.audit_local);
        assert!(config.repair);
        assert!(!options.watch);
        assert_eq!(
            options.interval,
            Duration::from_secs(DEFAULT_WATCH_INTERVAL_SECONDS)
        );
        assert_eq!(
            options.error_retry_interval,
            Duration::from_secs(DEFAULT_ERROR_RETRY_SECONDS)
        );
        assert!(!options.quiet_up_to_date);
        assert!(!options.quiet_up_to_date_explicit);
    }

    #[test]
    fn parses_explicit_source_and_disable_repair() {
        let options = parse(&[
            "bat-official-sync",
            "--server-info-url",
            "https://yostar-serverinfo.bluearchiveyostar.com/r93_fixture.json",
            "--connection-group",
            "Prod-Audit",
            "--app-version",
            "1.70.0",
            "--no-audit-local",
            "--no-repair",
            "--unzip",
            "/usr/bin/unzip",
        ])
        .unwrap();
        let config = options.config;

        assert!(!config.auto_discover);
        assert_eq!(config.connection_group.as_deref(), Some("Prod-Audit"));
        assert_eq!(config.app_version.as_deref(), Some("1.70.0"));
        assert!(!config.audit_local);
        assert!(!config.repair);
        assert_eq!(config.unzip_command, PathBuf::from("/usr/bin/unzip"));
        assert!(matches!(
            config.server_info_source,
            Some(OfficialServerInfoSource::OfficialUrl(ref url))
                if url == "https://yostar-serverinfo.bluearchiveyostar.com/r93_fixture.json"
        ));
    }

    #[test]
    fn parses_watch_defaults_to_one_hour_and_quiet_up_to_date() {
        let options = parse(&[
            "bat-official-sync",
            "--auto-discover",
            "--watch",
            "--interval",
            "30m",
        ])
        .unwrap();

        assert!(options.watch);
        assert_eq!(options.interval, Duration::from_secs(30 * 60));
        assert_eq!(
            options.error_retry_interval,
            Duration::from_secs(DEFAULT_ERROR_RETRY_SECONDS)
        );
        assert!(options.quiet_up_to_date);
        assert!(!options.quiet_up_to_date_explicit);
    }

    #[test]
    fn parses_explicit_watch_error_retry_interval() {
        let options = parse(&[
            "bat-official-sync",
            "--watch",
            "--interval",
            "1h",
            "--error-retry",
            "45s",
        ])
        .unwrap();
        assert_eq!(options.interval, Duration::from_secs(3600));
        assert_eq!(options.error_retry_interval, Duration::from_secs(45));

        let options = parse(&[
            "bat-official-sync",
            "--watch",
            "--error-retry-seconds",
            "30",
        ])
        .unwrap();
        assert_eq!(options.error_retry_interval, Duration::from_secs(30));
    }

    #[test]
    fn explicit_no_quiet_up_to_date_overrides_watch_default() {
        let options = parse(&[
            "bat-official-sync",
            "--watch",
            "--no-quiet-up-to-date",
            "--interval",
            "1h",
        ])
        .unwrap();

        assert!(options.watch);
        assert!(!options.quiet_up_to_date);
        assert!(options.quiet_up_to_date_explicit);
    }

    #[test]
    fn rejects_watch_dry_run_and_zero_interval() {
        let error = parse(&["bat-official-sync", "--watch", "--dry-run"]).unwrap_err();
        assert!(error.to_string().contains("watch mode"));

        let error =
            parse(&["bat-official-sync", "--watch", "--interval-seconds", "0"]).unwrap_err();
        assert!(error.to_string().contains("greater than zero"));

        let error =
            parse(&["bat-official-sync", "--watch", "--error-retry-seconds", "0"]).unwrap_err();
        assert!(error.to_string().contains("error retry interval"));
    }

    #[test]
    fn parses_duration_units() {
        assert_eq!(parse_duration("1h").unwrap(), Duration::from_secs(3600));
        assert_eq!(parse_duration("60m").unwrap(), Duration::from_secs(3600));
        assert_eq!(parse_duration("90s").unwrap(), Duration::from_secs(90));
        assert_eq!(parse_duration("250ms").unwrap(), Duration::from_millis(250));
        assert_eq!(parse_duration("3600").unwrap(), Duration::from_secs(3600));
    }

    #[test]
    fn quiet_up_to_date_suppresses_only_clean_reports() {
        assert!(!should_print_status(OfficialUpdateStatus::UpToDate, true));
        assert!(should_print_status(OfficialUpdateStatus::Downloaded, true));
        assert!(should_print_status(
            OfficialUpdateStatus::WouldDownload,
            true
        ));
        assert!(should_print_status(OfficialUpdateStatus::UpToDate, false));
    }

    #[test]
    fn status_string_is_stable() {
        assert_eq!(OfficialUpdateStatus::UpToDate.as_str(), "up_to_date");
        assert_eq!(
            OfficialUpdateStatus::WouldDownload.as_str(),
            "would_download"
        );
        assert_eq!(OfficialUpdateStatus::Downloaded.as_str(), "downloaded");
    }
}