use std::collections::HashMap;
use std::path::Path;

pub struct ElevatedSandboxCaptureRequest<'a> {
    pub policy_json_or_preset: &'a str,
    pub sandbox_policy_cwd: &'a Path,
    pub codex_home: &'a Path,
    pub command: Vec<String>,
    pub cwd: &'a Path,
    pub env_map: HashMap<String, String>,
    pub timeout_ms: Option<u64>,
    pub use_private_desktop: bool,
    pub proxy_enforced: bool,
}

mod windows_impl {
    use super::ElevatedSandboxCaptureRequest;
    use crate::acl::allow_null_device;
    use crate::allow::AllowDenyPaths;
    use crate::allow::compute_allow_paths;
    use crate::cap::load_or_create_cap_sids;
    use crate::env::ensure_non_interactive_pager;
    use crate::env::inherit_path_env;
    use crate::env::normalize_null_device_env;
    use crate::helper_materialization::HelperExecutable;
    use crate::helper_materialization::resolve_helper_for_launch;
    use crate::identity::require_logon_sandbox_creds;
    use crate::ipc_framed::FramedMessage;
    use crate::ipc_framed::Message;
    use crate::ipc_framed::OutputStream;
    use crate::ipc_framed::SpawnRequest;
    use crate::ipc_framed::decode_bytes;
    use crate::ipc_framed::read_frame;
    use crate::ipc_framed::write_frame;
    use crate::logging::log_failure;
    use crate::logging::log_note;
    use crate::logging::log_start;
    use crate::logging::log_success;
    use crate::policy::SandboxPolicy;
    use crate::policy::parse_policy;
    use crate::token::convert_string_sid_to_sid;
    use crate::winutil::quote_windows_arg;
    use crate::winutil::resolve_sid;
    use crate::winutil::string_from_sid_bytes;
    use crate::winutil::to_wide;
    use anyhow::Result;
    use rand::Rng;
    use rand::SeedableRng;
    use rand::rngs::SmallRng;
    use std::collections::HashMap;
    use std::ffi::c_void;
    use std::fs::File;
    use std::io;
    use std::os::windows::io::FromRawHandle;
    use std::path::Path;
    use std::path::PathBuf;
    use std::ptr;
    use windows_sys::Win32::Foundation::CloseHandle;
    use windows_sys::Win32::Foundation::GetLastError;
    use windows_sys::Win32::Foundation::HANDLE;
    use windows_sys::Win32::Security::Authorization::ConvertStringSecurityDescriptorToSecurityDescriptorW;
    use windows_sys::Win32::Security::PSECURITY_DESCRIPTOR;
    use windows_sys::Win32::Security::SECURITY_ATTRIBUTES;
    use windows_sys::Win32::System::Diagnostics::Debug::SetErrorMode;
    use windows_sys::Win32::System::Pipes::ConnectNamedPipe;
    use windows_sys::Win32::System::Pipes::CreateNamedPipeW;
    const PIPE_ACCESS_INBOUND: u32 = 0x0000_0001;
    const PIPE_ACCESS_OUTBOUND: u32 = 0x0000_0002;
    use windows_sys::Win32::System::Pipes::PIPE_READMODE_BYTE;
    use windows_sys::Win32::System::Pipes::PIPE_TYPE_BYTE;
    use windows_sys::Win32::System::Pipes::PIPE_WAIT;
    use windows_sys::Win32::System::Threading::CreateProcessWithLogonW;
    use windows_sys::Win32::System::Threading::LOGON_WITH_PROFILE;
    use windows_sys::Win32::System::Threading::PROCESS_INFORMATION;
    use windows_sys::Win32::System::Threading::STARTUPINFOW;

    /// Ensures the parent directory of a path exists before writing to it.
    /// Walks upward from `start` to locate the git worktree root, following gitfile redirects.
    fn find_git_root(start: &Path) -> Option<PathBuf> {
        let mut cur = dunce::canonicalize(start).ok()?;
        loop {
            let marker = cur.join(".git");
            if marker.is_dir() {
                return Some(cur);
            }
            if marker.is_file() {
                if let Ok(txt) = std::fs::read_to_string(&marker)
                    && let Some(rest) = txt.trim().strip_prefix("gitdir:")
                {
                    let gitdir = rest.trim();
                    let resolved = if Path::new(gitdir).is_absolute() {
                        PathBuf::from(gitdir)
                    } else {
                        cur.join(gitdir)
                    };
                    return resolved.parent().map(|p| p.to_path_buf()).or(Some(cur));
                }
                return Some(cur);
            }
            let parent = cur.parent()?;
            if parent == cur {
                return None;
            }
            cur = parent.to_path_buf();
        }
    }

    /// Creates the sandbox user's Codex home directory if it does not already exist.
    fn ensure_codex_home_exists(p: &Path) -> Result<()> {
        std::fs::create_dir_all(p)?;
        Ok(())
    }

    /// Adds a git safe.directory entry to the environment when running inside a repository.
    /// git will not otherwise allow the Sandbox user to run git commands on the repo directory
    /// which is owned by the primary user.
    fn inject_git_safe_directory(
        env_map: &mut HashMap<String, String>,
        cwd: &Path,
        _logs_base_dir: Option<&Path>,
    ) {
        if let Some(git_root) = find_git_root(cwd) {
            let mut cfg_count: usize = env_map
                .get("GIT_CONFIG_COUNT")
                .and_then(|v| v.parse::<usize>().ok())
                .unwrap_or(0);
            let git_path = git_root.to_string_lossy().replace("\\\\", "/");
            env_map.insert(
                format!("GIT_CONFIG_KEY_{cfg_count}"),
                "safe.directory".to_string(),
            );
            env_map.insert(format!("GIT_CONFIG_VALUE_{cfg_count}"), git_path);
            cfg_count += 1;
            env_map.insert("GIT_CONFIG_COUNT".to_string(), cfg_count.to_string());
        }
    }

    /// Resolves the command runner path, preferring CODEX_HOME/.sandbox/bin.
    fn find_runner_exe(codex_home: &Path, log_dir: Option<&Path>) -> PathBuf {
        resolve_helper_for_launch(HelperExecutable::CommandRunner, codex_home, log_dir)
    }

    /// Generates a unique named-pipe path used to communicate with the runner process.
    fn pipe_name(suffix: &str) -> String {
        let mut rng = SmallRng::from_entropy();
        format!(
            r"\\.\pipe\codex-runner-{:x}-{}",
            rng.r#gen::<u128>(),
            suffix
        )
    }

    /// Creates a named pipe whose DACL only allows the sandbox user to connect.
    fn create_named_pipe(name: &str, access: u32, sandbox_sid: &str) -> io::Result<HANDLE> {
        let sddl = to_wide(format!("D:(A;;GA;;;{sandbox_sid})"));
        let mut sd: PSECURITY_DESCRIPTOR = ptr::null_mut();
        let ok = unsafe {
            ConvertStringSecurityDescriptorToSecurityDescriptorW(
                sddl.as_ptr(),
                1, // SDDL_REVISION_1
                &mut sd,
                ptr::null_mut(),
            )
        };
        if ok == 0 {
            return Err(io::Error::from_raw_os_error(unsafe {
                GetLastError() as i32
            }));
        }
        let mut sa = SECURITY_ATTRIBUTES {
            nLength: std::mem::size_of::<SECURITY_ATTRIBUTES>() as u32,
            lpSecurityDescriptor: sd,
            bInheritHandle: 0,
        };
        let wide = to_wide(name);
        let h = unsafe {
            CreateNamedPipeW(
                wide.as_ptr(),
                access,
                PIPE_TYPE_BYTE | PIPE_READMODE_BYTE | PIPE_WAIT,
                1,
                65536,
                65536,
                0,
                &mut sa as *mut SECURITY_ATTRIBUTES,
            )
        };
        if h == 0 || h == windows_sys::Win32::Foundation::INVALID_HANDLE_VALUE {
            return Err(io::Error::from_raw_os_error(unsafe {
                GetLastError() as i32
            }));
        }
        Ok(h)
    }

    /// Waits for a client connection on the named pipe, tolerating an existing connection.
    fn connect_pipe(h: HANDLE) -> io::Result<()> {
        let ok = unsafe { ConnectNamedPipe(h, ptr::null_mut()) };
        if ok == 0 {
            let err = unsafe { GetLastError() };
            const ERROR_PIPE_CONNECTED: u32 = 535;
            if err != ERROR_PIPE_CONNECTED {
                return Err(io::Error::from_raw_os_error(err as i32));
            }
        }
        Ok(())
    }

    pub use crate::windows_impl::CaptureResult;

    fn read_spawn_ready(pipe_read: &mut File) -> Result<()> {
        let msg = read_frame(pipe_read)?
            .ok_or_else(|| anyhow::anyhow!("runner pipe closed before spawn_ready"))?;
        match msg.message {
            Message::SpawnReady { .. } => Ok(()),
            Message::Error { payload } => Err(anyhow::anyhow!("runner error: {}", payload.message)),
            other => Err(anyhow::anyhow!(
                "expected spawn_ready from runner, got {other:?}"
            )),
        }
    }

    /// Launches the command runner under the sandbox user and captures its output.
    #[allow(clippy::too_many_arguments)]
    pub fn run_windows_sandbox_capture(
        request: ElevatedSandboxCaptureRequest<'_>,
    ) -> Result<CaptureResult> {
        let ElevatedSandboxCaptureRequest {
            policy_json_or_preset,
            sandbox_policy_cwd,
            codex_home,
            command,
            cwd,
            mut env_map,
            timeout_ms,
            use_private_desktop,
            proxy_enforced,
        } = request;
        let policy = parse_policy(policy_json_or_preset)?;
        normalize_null_device_env(&mut env_map);
        ensure_non_interactive_pager(&mut env_map);
        inherit_path_env(&mut env_map);
        inject_git_safe_directory(&mut env_map, cwd, None);
        let current_dir = cwd.to_path_buf();
        // Use a temp-based log dir that the sandbox user can write.
        let sandbox_base = codex_home.join(".sandbox");
        ensure_codex_home_exists(&sandbox_base)?;

        let logs_base_dir: Option<&Path> = Some(sandbox_base.as_path());
        log_start(&command, logs_base_dir);
        let sandbox_creds = require_logon_sandbox_creds(
            &policy,
            sandbox_policy_cwd,
            cwd,
            &env_map,
            codex_home,
            proxy_enforced,
        )?;
        let sandbox_sid = resolve_sid(&sandbox_creds.username).map_err(|err: anyhow::Error| {
            io::Error::new(io::ErrorKind::PermissionDenied, err.to_string())
        })?;
        let sandbox_sid = string_from_sid_bytes(&sandbox_sid)
            .map_err(|err| io::Error::new(io::ErrorKind::PermissionDenied, err))?;
        // Build capability SID for ACL grants.
        if matches!(
            &policy,
            SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. }
        ) {
            anyhow::bail!("DangerFullAccess and ExternalSandbox are not supported for sandboxing")
        }
        let caps = load_or_create_cap_sids(codex_home)?;
        let (psid_to_use, cap_sids) = match &policy {
            SandboxPolicy::ReadOnly { .. } => (
                unsafe { convert_string_sid_to_sid(&caps.readonly).unwrap() },
                vec![caps.readonly.clone()],
            ),
            SandboxPolicy::WorkspaceWrite { .. } => (
                unsafe { convert_string_sid_to_sid(&caps.workspace).unwrap() },
                vec![
                    caps.workspace.clone(),
                    crate::cap::workspace_cap_sid_for_cwd(codex_home, cwd)?,
                ],
            ),
            SandboxPolicy::DangerFullAccess | SandboxPolicy::ExternalSandbox { .. } => {
                unreachable!("DangerFullAccess handled above")
            }
        };

        let AllowDenyPaths { allow: _, deny: _ } =
            compute_allow_paths(&policy, sandbox_policy_cwd, &current_dir, &env_map);
        // Deny/allow ACEs are now applied during setup; avoid per-command churn.
        unsafe {
            allow_null_device(psid_to_use);
        }

        let pipe_in_name = pipe_name("in");
        let pipe_out_name = pipe_name("out");
        let h_pipe_in = create_named_pipe(&pipe_in_name, PIPE_ACCESS_OUTBOUND, &sandbox_sid)?;
        let h_pipe_out = create_named_pipe(&pipe_out_name, PIPE_ACCESS_INBOUND, &sandbox_sid)?;

        // Launch runner as sandbox user via CreateProcessWithLogonW.
        let runner_exe = find_runner_exe(codex_home, logs_base_dir);
        let runner_cmdline = runner_exe
            .to_str()
            .map(|s| s.to_string())
            .unwrap_or_else(|| "codex-command-runner.exe".to_string());
        let runner_full_cmd = format!(
            "{} {} {}",
            quote_windows_arg(&runner_cmdline),
            quote_windows_arg(&format!("--pipe-in={pipe_in_name}")),
            quote_windows_arg(&format!("--pipe-out={pipe_out_name}"))
        );
        let mut cmdline_vec: Vec<u16> = to_wide(&runner_full_cmd);
        let exe_w: Vec<u16> = to_wide(&runner_cmdline);
        let cwd_w: Vec<u16> = to_wide(cwd);

        // Minimal CPWL launch: inherit env, no desktop override, no handle inheritance.
        let env_block: Option<Vec<u16>> = None;
        let mut si: STARTUPINFOW = unsafe { std::mem::zeroed() };
        si.cb = std::mem::size_of::<STARTUPINFOW>() as u32;
        let mut pi: PROCESS_INFORMATION = unsafe { std::mem::zeroed() };
        let user_w = to_wide(&sandbox_creds.username);
        let domain_w = to_wide(".");
        let password_w = to_wide(&sandbox_creds.password);
        // Suppress WER/UI popups from the runner process so we can collect exit codes.
        let _ = unsafe { SetErrorMode(0x0001 | 0x0002) }; // SEM_FAILCRITICALERRORS | SEM_NOGPFAULTERRORBOX

        log_note(
            &format!(
                "runner launch: exe={} cmdline={} cwd={}",
                runner_exe.display(),
                runner_full_cmd,
                cwd.display()
            ),
            logs_base_dir,
        );

        // Ensure command line buffer is mutable and includes the exe as argv[0].
        let spawn_res = unsafe {
            CreateProcessWithLogonW(
                user_w.as_ptr(),
                domain_w.as_ptr(),
                password_w.as_ptr(),
                LOGON_WITH_PROFILE,
                exe_w.as_ptr(),
                cmdline_vec.as_mut_ptr(),
                windows_sys::Win32::System::Threading::CREATE_NO_WINDOW
                    | windows_sys::Win32::System::Threading::CREATE_UNICODE_ENVIRONMENT,
                env_block
                    .as_ref()
                    .map(|b| b.as_ptr() as *const c_void)
                    .unwrap_or(ptr::null()),
                cwd_w.as_ptr(),
                &si,
                &mut pi,
            )
        };
        if spawn_res == 0 {
            let err = unsafe { GetLastError() } as i32;
            log_note(
                &format!(
                    "runner launch failed before process start: exe={} cmdline={} error={err}",
                    runner_exe.display(),
                    runner_full_cmd
                ),
                logs_base_dir,
            );
            return Err(anyhow::anyhow!("CreateProcessWithLogonW failed: {}", err));
        }

        if let Err(err) = connect_pipe(h_pipe_in) {
            unsafe {
                CloseHandle(h_pipe_in);
                CloseHandle(h_pipe_out);
                if pi.hThread != 0 {
                    CloseHandle(pi.hThread);
                }
                if pi.hProcess != 0 {
                    CloseHandle(pi.hProcess);
                }
            }
            return Err(err.into());
        }
        if let Err(err) = connect_pipe(h_pipe_out) {
            unsafe {
                CloseHandle(h_pipe_in);
                CloseHandle(h_pipe_out);
                if pi.hThread != 0 {
                    CloseHandle(pi.hThread);
                }
                if pi.hProcess != 0 {
                    CloseHandle(pi.hProcess);
                }
            }
            return Err(err.into());
        }

        let result = (|| -> Result<CaptureResult> {
            let mut pipe_write = unsafe { File::from_raw_handle(h_pipe_in as _) };
            let mut pipe_read = unsafe { File::from_raw_handle(h_pipe_out as _) };

            let spawn_request = FramedMessage {
                version: 1,
                message: Message::SpawnRequest {
                    payload: Box::new(SpawnRequest {
                        command: command.clone(),
                        cwd: cwd.to_path_buf(),
                        env: env_map.clone(),
                        policy_json_or_preset: policy_json_or_preset.to_string(),
                        sandbox_policy_cwd: sandbox_policy_cwd.to_path_buf(),
                        codex_home: sandbox_base.clone(),
                        real_codex_home: codex_home.to_path_buf(),
                        cap_sids,
                        timeout_ms,
                        tty: false,
                        stdin_open: false,
                        use_private_desktop,
                    }),
                },
            };
            write_frame(&mut pipe_write, &spawn_request)?;
            read_spawn_ready(&mut pipe_read)?;
            drop(pipe_write);

            let mut stdout = Vec::new();
            let mut stderr = Vec::new();
            let (exit_code, timed_out) = loop {
                let msg = read_frame(&mut pipe_read)?
                    .ok_or_else(|| anyhow::anyhow!("runner pipe closed before exit"))?;
                match msg.message {
                    Message::SpawnReady { .. } => {}
                    Message::Output { payload } => {
                        let bytes = decode_bytes(&payload.data_b64)?;
                        match payload.stream {
                            OutputStream::Stdout => stdout.extend_from_slice(&bytes),
                            OutputStream::Stderr => stderr.extend_from_slice(&bytes),
                        }
                    }
                    Message::Exit { payload } => break (payload.exit_code, payload.timed_out),
                    Message::Error { payload } => {
                        return Err(anyhow::anyhow!("runner error: {}", payload.message));
                    }
                    other => {
                        return Err(anyhow::anyhow!(
                            "unexpected runner message during capture: {other:?}"
                        ));
                    }
                }
            };

            if exit_code == 0 {
                log_success(&command, logs_base_dir);
            } else {
                log_failure(&command, &format!("exit code {}", exit_code), logs_base_dir);
            }

            Ok(CaptureResult {
                exit_code,
                stdout,
                stderr,
                timed_out,
            })
        })();

        unsafe {
            if pi.hThread != 0 {
                CloseHandle(pi.hThread);
            }
            if pi.hProcess != 0 {
                CloseHandle(pi.hProcess);
            }
        }

        result
    }

    #[cfg(test)]
    mod tests {
        use crate::policy::SandboxPolicy;

        fn workspace_policy(network_access: bool) -> SandboxPolicy {
            SandboxPolicy::WorkspaceWrite {
                writable_roots: Vec::new(),
                read_only_access: Default::default(),
                network_access,
                exclude_tmpdir_env_var: false,
                exclude_slash_tmp: false,
            }
        }

        #[test]
        fn applies_network_block_when_access_is_disabled() {
            assert!(!workspace_policy(false).has_full_network_access());
        }

        #[test]
        fn skips_network_block_when_access_is_allowed() {
            assert!(workspace_policy(true).has_full_network_access());
        }

        #[test]
        fn applies_network_block_for_read_only() {
            assert!(!SandboxPolicy::new_read_only_policy().has_full_network_access());
        }
    }
}

#[cfg(target_os = "windows")]
pub use windows_impl::run_windows_sandbox_capture;

#[cfg(not(target_os = "windows"))]
mod stub {
    use super::ElevatedSandboxCaptureRequest;
    use anyhow::Result;
    use anyhow::bail;

    #[derive(Debug, Default)]
    pub struct CaptureResult {
        pub exit_code: i32,
        pub stdout: Vec<u8>,
        pub stderr: Vec<u8>,
        pub timed_out: bool,
    }

    /// Stub implementation for non-Windows targets; sandboxing only works on Windows.
    #[allow(clippy::too_many_arguments)]
    pub fn run_windows_sandbox_capture(
        _request: ElevatedSandboxCaptureRequest<'_>,
    ) -> Result<CaptureResult> {
        bail!("Windows sandbox is only available on Windows")
    }
}

#[cfg(not(target_os = "windows"))]
pub use stub::run_windows_sandbox_capture;