mod cli;
mod event_processor;
mod event_processor_with_human_output;
mod event_processor_with_json_output;

use std::io::IsTerminal;
use std::io::Read;
use std::path::PathBuf;
use std::sync::Arc;

pub use cli::Cli;
use codex_core::codex_wrapper::CodexConversation;
use codex_core::codex_wrapper::{self};
use codex_core::config::Config;
use codex_core::config::ConfigOverrides;
use codex_core::config_types::SandboxMode;
use codex_core::protocol::AskForApproval;
use codex_core::protocol::Event;
use codex_core::protocol::EventMsg;
use codex_core::protocol::InputItem;
use codex_core::protocol::Op;
use codex_core::protocol::TaskCompleteEvent;
use codex_core::util::is_inside_git_repo;
use event_processor_with_human_output::EventProcessorWithHumanOutput;
use event_processor_with_json_output::EventProcessorWithJsonOutput;
use tracing::debug;
use tracing::error;
use tracing::info;
use tracing_subscriber::EnvFilter;

use crate::event_processor::CodexStatus;
use crate::event_processor::EventProcessor;

pub async fn run_main(cli: Cli, codex_linux_sandbox_exe: Option<PathBuf>) -> anyhow::Result<()> {
    let Cli {
        images,
        model,
        config_profile,
        full_auto,
        dangerously_bypass_approvals_and_sandbox,
        cwd,
        skip_git_repo_check,
        color,
        last_message_file,
        json: json_mode,
        sandbox_mode: sandbox_mode_cli_arg,
        prompt,
        config_overrides,
    } = cli;

    // Determine the prompt based on CLI arg and/or stdin.
    let prompt = match prompt {
        Some(p) if p != "-" => p,
        // Either `-` was passed or no positional arg.
        maybe_dash => {
            // When no arg (None) **and** stdin is a TTY, bail out early – unless the
            // user explicitly forced reading via `-`.
            let force_stdin = matches!(maybe_dash.as_deref(), Some("-"));

            if std::io::stdin().is_terminal() && !force_stdin {
                eprintln!(
                    "No prompt provided. Either specify one as an argument or pipe the prompt into stdin."
                );
                std::process::exit(1);
            }

            // Ensure the user knows we are waiting on stdin, as they may
            // have gotten into this state by mistake. If so, and they are not
            // writing to stdin, Codex will hang indefinitely, so this should
            // help them debug in that case.
            if !force_stdin {
                eprintln!("Reading prompt from stdin...");
            }
            let mut buffer = String::new();
            if let Err(e) = std::io::stdin().read_to_string(&mut buffer) {
                eprintln!("Failed to read prompt from stdin: {e}");
                std::process::exit(1);
            } else if buffer.trim().is_empty() {
                eprintln!("No prompt provided via stdin.");
                std::process::exit(1);
            }
            buffer
        }
    };

    let (stdout_with_ansi, stderr_with_ansi) = match color {
        cli::Color::Always => (true, true),
        cli::Color::Never => (false, false),
        cli::Color::Auto => (
            std::io::stdout().is_terminal(),
            std::io::stderr().is_terminal(),
        ),
    };

    // TODO(mbolin): Take a more thoughtful approach to logging.
    let default_level = "error";
    let _ = tracing_subscriber::fmt()
        // Fallback to the `default_level` log filter if the environment
        // variable is not set _or_ contains an invalid value
        .with_env_filter(
            EnvFilter::try_from_default_env()
                .or_else(|_| EnvFilter::try_new(default_level))
                .unwrap_or_else(|_| EnvFilter::new(default_level)),
        )
        .with_ansi(stderr_with_ansi)
        .with_writer(std::io::stderr)
        .try_init();

    let sandbox_mode = if full_auto {
        Some(SandboxMode::WorkspaceWrite)
    } else if dangerously_bypass_approvals_and_sandbox {
        Some(SandboxMode::DangerFullAccess)
    } else {
        sandbox_mode_cli_arg.map(Into::<SandboxMode>::into)
    };

    // Load configuration and determine approval policy
    let overrides = ConfigOverrides {
        model,
        config_profile,
        // This CLI is intended to be headless and has no affordances for asking
        // the user for approval.
        approval_policy: Some(AskForApproval::Never),
        sandbox_mode,
        cwd: cwd.map(|p| p.canonicalize().unwrap_or(p)),
        model_provider: None,
        codex_linux_sandbox_exe,
        base_instructions: None,
    };
    // Parse `-c` overrides.
    let cli_kv_overrides = match config_overrides.parse_overrides() {
        Ok(v) => v,
        Err(e) => {
            eprintln!("Error parsing -c overrides: {e}");
            std::process::exit(1);
        }
    };

    let config = Config::load_with_cli_overrides(cli_kv_overrides, overrides)?;
    let mut event_processor: Box<dyn EventProcessor> = if json_mode {
        Box::new(EventProcessorWithJsonOutput::new(last_message_file.clone()))
    } else {
        Box::new(EventProcessorWithHumanOutput::create_with_ansi(
            stdout_with_ansi,
            &config,
            last_message_file.clone(),
        ))
    };

    // Print the effective configuration and prompt so users can see what Codex
    // is using.
    event_processor.print_config_summary(&config, &prompt);

    if !skip_git_repo_check && !is_inside_git_repo(&config) {
        eprintln!("Not inside a Git repo and --skip-git-repo-check was not specified.");
        std::process::exit(1);
    }

    let CodexConversation {
        codex: codex_wrapper,
        session_configured,
        ctrl_c,
        ..
    } = codex_wrapper::init_codex(config).await?;
    let codex = Arc::new(codex_wrapper);
    info!("Codex initialized with event: {session_configured:?}");

    let (tx, mut rx) = tokio::sync::mpsc::unbounded_channel::<Event>();
    {
        let codex = codex.clone();
        tokio::spawn(async move {
            loop {
                let interrupted = ctrl_c.notified();
                tokio::select! {
                    _ = interrupted => {
                        // Forward an interrupt to the codex so it can abort any in‑flight task.
                        let _ = codex
                            .submit(
                                Op::Interrupt,
                            )
                            .await;

                        // Exit the inner loop and return to the main input prompt.  The codex
                        // will emit a `TurnInterrupted` (Error) event which is drained later.
                        break;
                    }
                    res = codex.next_event() => match res {
                        Ok(event) => {
                            debug!("Received event: {event:?}");
                            if let Err(e) = tx.send(event) {
                                error!("Error sending event: {e:?}");
                                break;
                            }
                        },
                        Err(e) => {
                            error!("Error receiving event: {e:?}");
                            break;
                        }
                    }
                }
            }
        });
    }

    // Send images first, if any.
    if !images.is_empty() {
        let items: Vec<InputItem> = images
            .into_iter()
            .map(|path| InputItem::LocalImage { path })
            .collect();
        let initial_images_event_id = codex.submit(Op::UserInput { items }).await?;
        info!("Sent images with event ID: {initial_images_event_id}");
        while let Ok(event) = codex.next_event().await {
            if event.id == initial_images_event_id
                && matches!(
                    event.msg,
                    EventMsg::TaskComplete(TaskCompleteEvent {
                        last_agent_message: _,
                    })
                )
            {
                break;
            }
        }
    }

    // Send the prompt.
    let items: Vec<InputItem> = vec![InputItem::Text { text: prompt }];
    let initial_prompt_task_id = codex.submit(Op::UserInput { items }).await?;
    info!("Sent prompt with event ID: {initial_prompt_task_id}");

    // Run the loop until the task is complete.
    while let Some(event) = rx.recv().await {
        let shutdown: CodexStatus = event_processor.process_event(event);
        match shutdown {
            CodexStatus::Running => continue,
            CodexStatus::InitiateShutdown => {
                codex.submit(Op::Shutdown).await?;
            }
            CodexStatus::Shutdown => {
                break;
            }
        }
    }

    Ok(())
}