use futures_util::StreamExt;
use miette::{IntoDiagnostic as _, Result};
use std::net::SocketAddr;
use tonic::{Request, Response, Status};
use tracing::{debug, error, info, warn};

use common::runner::v1::{
    Ack, LogItem,
    runner_server::{Runner, RunnerServer},
};
use common::{MqConfig, publish_job_result};
use std::sync::Arc;

use crate::persist::Persist;

fn parse_owner_repo(repo_url: &str) -> Option<(String, String)> {
    let url = repo_url.trim_end_matches(".git");
    if let Some(rest) = url.strip_prefix("https://").or_else(|| url.strip_prefix("http://")) {
        let parts: Vec<&str> = rest.split('/').collect();
        if parts.len() >= 3 { return Some((parts[1].to_string(), parts[2].to_string())); }
    } else if let Some(rest) = url.strip_prefix("ssh://") {
        // ssh://git@host/owner/repo
        let after_host = rest.splitn(2, '/').nth(1)?;
        let parts: Vec<&str> = after_host.split('/').collect();
        if parts.len() >= 2 { return Some((parts[0].to_string(), parts[1].to_string())); }
    } else if let Some(idx) = url.find(':') {
        // git@host:owner/repo
        let after = &url[idx+1..];
        let parts: Vec<&str> = after.split('/').collect();
        if parts.len() >= 2 { return Some((parts[0].to_string(), parts[1].to_string())); }
    }
    None
}

pub struct RunnerSvc {
    mq_cfg: MqConfig,
    persist: Arc<Persist>,
}

impl RunnerSvc {
    pub fn new(mq_cfg: MqConfig, persist: Arc<Persist>) -> Self {
        Self { mq_cfg, persist }
    }
}

#[tonic::async_trait]
impl Runner for RunnerSvc {
    async fn stream_logs(
        &self,
        request: Request<tonic::Streaming<LogItem>>,
    ) -> std::result::Result<Response<Ack>, Status> {
        let mut stream = request.into_inner();
        let mut req_id: Option<uuid::Uuid> = None;
        let mut repo_url: Option<String> = None;
        let mut commit_sha: Option<String> = None;
        let mut exit_code: i32 = 0;
        let mut success: bool = true;
        let mut lines_stdout: usize = 0;
        let mut lines_stderr: usize = 0;
        let mut got_end: bool = false;
        let mut seq: i64 = 0;

        debug!("runner log stream opened");
        while let Some(item) = stream
            .next()
            .await
            .transpose()
            .map_err(|e| Status::internal(e.to_string()))?
        {
            // Correlate request id
            if req_id.is_none() {
                match uuid::Uuid::parse_str(&item.request_id) {
                    Ok(u) => {
                        debug!(request_id = %u, "runner log stream identified");
                        req_id = Some(u)
                    }
                    Err(_) => {
                        warn!(request_id = %item.request_id, "invalid request_id from runner");
                    }
                }
            }
            if let Some(ev) = item.event {
                match ev {
                    common::runner::v1::log_item::Event::Log(chunk) => {
                        if chunk.stderr {
                            lines_stderr += 1;
                            debug!(request_id = %item.request_id, line = %chunk.line, "runner:stderr");
                        } else {
                            lines_stdout += 1;
                            debug!(request_id = %item.request_id, line = %chunk.line, "runner:stdout");
                        }
                        // Best effort: persist the line if we have a parsed UUID
                        if let Some(id) = req_id {
                            if let Err(e) = self.persist.record_log_line(id, seq, chunk.stderr, &chunk.line).await {
                                warn!(error = %e, request_id = %id, seq = seq, "failed to persist log line");
                            }
                            seq += 1;
                        }
                    }
                    common::runner::v1::log_item::Event::End(end) => {
                        exit_code = end.exit_code;
                        success = end.success;
                        repo_url = Some(end.repo_url);
                        commit_sha = Some(end.commit_sha);
                        got_end = true;
                        debug!(exit_code, success, "runner log stream received End");
                    }
                }
            }
        }

        debug!(lines_stdout, lines_stderr, got_end, "runner log stream closed");
        // Publish final status if we have enough context
        if let (Some(id), Some(repo), Some(sha)) =
            (req_id.as_ref(), repo_url.as_ref(), commit_sha.as_ref())
        {
            let mut result = common::messages::JobResult::new(
                id.clone(),
                repo.clone(),
                sha.clone(),
                success,
                exit_code,
                None,
            );
            // Try to parse owner/repo for downstream integrations to avoid reparsing URLs
            if let Some((owner, name)) = parse_owner_repo(&repo) {
                result.repo_owner = Some(owner);
                result.repo_name = Some(name);
            }
            if let Err(e) = publish_job_result(&self.mq_cfg, &result).await {
                error!(error = %e, request_id = %id, "failed to publish JobResult");
            }
        } else {
            warn!(
                have_req_id = req_id.is_some(),
                have_repo = repo_url.is_some(),
                have_sha = commit_sha.is_some(),
                "missing context for JobResult; skipping publish"
            );
        }

        Ok(Response::new(Ack { ok: true }))
    }
}

pub async fn serve_with_shutdown(
    addr: SocketAddr,
    mq_cfg: MqConfig,
    persist: Arc<Persist>,
    shutdown: impl std::future::Future<Output = ()>,
) -> Result<()> {
    info!(%addr, "gRPC server starting");
    tonic::transport::Server::builder()
        .add_service(RunnerServer::new(RunnerSvc::new(mq_cfg, persist)))
        .serve_with_shutdown(addr, shutdown)
        .await
        .into_diagnostic()
}