/* Copyright (C) 2025 OnionHEN / LightningMods
 *
 * Serialized Toolbox ELF inject into one SceShellUI PID.
 * When to inject (immediate vs rest) lives in daemon_inject.cpp.
 */
#pragma once

#include <mutex>
#include <sys/types.h>

#include <onion/ready.h>

namespace onion {

enum class ToolboxInjectionResult {
  AlreadyReady,
  Injected,
  TargetNotFound,
  InjectFailed,
  ReadyTimeout,
  TargetChanged,
};

struct ToolboxInjectionOutcome {
  ToolboxInjectionResult result;
  pid_t pid;

  bool ready() const noexcept {
    return result == ToolboxInjectionResult::AlreadyReady ||
           result == ToolboxInjectionResult::Injected;
  }
};

class ToolboxInject final {
public:
  bool is_ready_for(pid_t pid) const noexcept {
    return onion_ready_matches_pid(ONION_READY_TOOLBOX, pid);
  }

  template <typename ResolvePid, typename InjectFn>
  ToolboxInjectionOutcome inject(ResolvePid resolve_pid, InjectFn inject_fn,
                                 int timeout_ms, int poll_ms,
                                 pid_t expected_pid = 0) {
    std::lock_guard<std::mutex> lock(mutex_);

    const pid_t resolved_before = resolve_pid();
    if (expected_pid > 1) {
      /* An event PID is authoritative; reject only an observed replacement. */
      if (resolved_before > 1 && resolved_before != expected_pid) {
        return {ToolboxInjectionResult::TargetChanged, expected_pid};
      }
    }
    const pid_t pid = expected_pid > 1 ? expected_pid : resolved_before;
    if (pid <= 0) {
      return {ToolboxInjectionResult::TargetNotFound, pid};
    }
    if (is_ready_for(pid)) {
      return {ToolboxInjectionResult::AlreadyReady, pid};
    }

    /* Stale marker is another PID; ready file is not the rest-resume signal. */
    onion_ready_clear(ONION_READY_TOOLBOX);
    if (!inject_fn(pid)) {
      onion_ready_clear(ONION_READY_TOOLBOX);
      return {ToolboxInjectionResult::InjectFailed, pid};
    }
    if (!onion_ready_wait_pid(ONION_READY_TOOLBOX, pid, timeout_ms, poll_ms)) {
      onion_ready_clear(ONION_READY_TOOLBOX);
      return {ToolboxInjectionResult::ReadyTimeout, pid};
    }

    const pid_t resolved_after = resolve_pid();
    if (resolved_after > 1 && resolved_after != pid) {
      onion_ready_clear(ONION_READY_TOOLBOX);
      return {ToolboxInjectionResult::TargetChanged, pid};
    }
    return {ToolboxInjectionResult::Injected, pid};
  }

private:
  mutable std::mutex mutex_;
};

} // namespace onion