#pragma once
// RunLive: run_live() / run_live_pty() of tai.py. Every command an agent runs for the user
// streams live into a StreamSink and is returned to the agent. With an ask function the
// command runs on a pty; when it stops on a prompt (sudo, ssh, y/n) ask(text, secret) gets
// the question and its answer is typed into the command. nullopt declines: the command gets
// end-of-file. Time spent waiting for the user does not count against the timeout.
#include "proc.h"
#include "sink.h"
#include <functional>
#include <optional>
#include <string>
#include <vector>
namespace detz::shell {
constexpr int kShellTimeout = 120;          // SHELL_TIMEOUT
constexpr long kRunOutputCap = 4000000;     // RUN_OUTPUT_CAP
constexpr double kRunPromptIdle = 1.0;      // RUN_PROMPT_IDLE
constexpr int kRunMaxAsks = 20;             // RUN_MAX_ASKS
constexpr size_t kRunAnswerCap = 1000;      // RUN_ANSWER_CAP

// ask(text, secret): the user's answer, or nullopt to decline.
using AskFn = std::function<std::optional<std::string>(const std::string& text, bool secret)>;

// What to run: an argv list, or a shell command line (shell=True).
struct Command {
  std::vector<std::string> argv;
  std::optional<std::string> shell;
  static Command Argv(std::vector<std::string> a) { Command c; c.argv = std::move(a); return c; }
  static Command Shell(std::string line) { Command c; c.shell = std::move(line); return c; }
};

// (returncode, output, elapsed seconds, timed_out)
struct RunResult { int code{0}; std::string output; double elapsed{0}; bool timedOut{false}; };
// Ctrl-C landed while the command ran: the child is already killed and reaped.
struct RunInterrupted : public std::runtime_error {
  RunInterrupted() : std::runtime_error("interrupted") {}
};

struct RunLiveOptions {
  double timeout{kShellTimeout};
  std::optional<std::string> cwd;
  const EnvMap* env{nullptr};      // null: inherit
  StreamSink* stream{nullptr};
  AskFn ask;                       // empty: no pty, no questions
  bool allow_interrupt{true};      // false: Ctrl-C is not ours (background workers)
};

class RunLive {
 public:
  // run_live(): pty path when ask is set, pipe path otherwise. Throws OsError when the
  // command cannot start (missing program, bad cwd).
  static RunResult Run(const Command& command, const RunLiveOptions& options = RunLiveOptions());
  static RunResult RunPty(const Command& command, const RunLiveOptions& options);
  // RUN_CTRL_RE.sub("", text)
  static std::string StripControl(const std::string& text);
  // RUN_PROMPT_RE.search(text) is not None
  static bool LooksLikePrompt(const std::string& text);
};
}  // namespace detz::shell