#pragma once

#include <stdbool.h>

#include "nvim/pos_defs.h"

/// A list used for saving values of "emsg_silent".  Used by ex_try() to save the
/// value of "emsg_silent" if it was non-zero.  When this is done, the CSF_SILENT
/// flag below is set.
typedef struct eslist_elem eslist_T;
struct eslist_elem {
  int saved_emsg_silent;  ///< saved value of "emsg_silent"
  eslist_T *next;         ///< next element on the list
};

/// For conditional commands a stack is kept of nested conditionals.
/// When cs_idx < 0, there is no conditional command.
enum { CSTACK_LEN = 50, };

typedef struct {
  int cs_flags[CSTACK_LEN];       ///< CSF_ flags
  char cs_pending[CSTACK_LEN];    ///< CSTP_: what's pending in ":finally"
  union {
    void *csp_rv[CSTACK_LEN];     ///< return typeval for pending return
    void *csp_ex[CSTACK_LEN];     ///< exception for pending throw
  } cs_pend;
  void *cs_forinfo[CSTACK_LEN];   ///< info used by ":for"
  int cs_line[CSTACK_LEN];        ///< line nr of ":while"/":for" line
  int cs_idx;                     ///< current entry, or -1 if none
  int cs_looplevel;               ///< nr of nested ":while"s and ":for"s
  int cs_trylevel;                ///< nr of nested ":try"s
  eslist_T *cs_emsg_silent_list;  ///< saved values of "emsg_silent"
  int cs_lflags;                  ///< loop flags: CSL_ flags
} cstack_T;
#define cs_rettv       cs_pend.csp_rv
#define cs_exception   cs_pend.csp_ex

/// There is no CSF_IF, the lack of CSF_WHILE, CSF_FOR and CSF_TRY means ":if"
/// was used.
enum {
  CSF_TRUE     = 0x0001,  ///< condition was TRUE
  CSF_ACTIVE   = 0x0002,  ///< current state is active
  CSF_ELSE     = 0x0004,  ///< ":else" has been passed
  CSF_WHILE    = 0x0008,  ///< is a ":while"
  CSF_FOR      = 0x0010,  ///< is a ":for"

  CSF_TRY      = 0x0100,  ///< is a ":try"
  CSF_FINALLY  = 0x0200,  ///< ":finally" has been passed
  CSF_THROWN   = 0x0800,  ///< exception thrown to this try conditional
  CSF_CAUGHT   = 0x1000,  ///< exception caught by this try conditional
  CSF_FINISHED = 0x2000,  ///< CSF_CAUGHT was handled by finish_exception()
  CSF_SILENT   = 0x4000,  ///< "emsg_silent" reset by ":try"
};
// Note that CSF_ELSE is only used when CSF_TRY and CSF_WHILE are unset
// (an ":if"), and CSF_SILENT is only used when CSF_TRY is set.

/// What's pending for being reactivated at the ":endtry" of this try
/// conditional:
enum {
  CSTP_NONE      = 0,   ///< nothing pending in ":finally" clause
  CSTP_ERROR     = 1,   ///< an error is pending
  CSTP_INTERRUPT = 2,   ///< an interrupt is pending
  CSTP_THROW     = 4,   ///< a throw is pending
  CSTP_BREAK     = 8,   ///< ":break" is pending
  CSTP_CONTINUE  = 16,  ///< ":continue" is pending
  CSTP_RETURN    = 24,  ///< ":return" is pending
  CSTP_FINISH    = 32,  ///< ":finish" is pending
};

/// Flags for the cs_lflags item in cstack_T.
enum {
  CSL_HAD_LOOP = 1,     ///< just found ":while" or ":for"
  CSL_HAD_ENDLOOP = 2,  ///< just found ":endwhile" or ":endfor"
  CSL_HAD_CONT = 4,     ///< just found ":continue"
  CSL_HAD_FINA = 8,     ///< just found ":finally"
};

/// A list of error messages that can be converted to an exception.  "throw_msg"
/// is only set in the first element of the list.  Usually, it points to the
/// original message stored in that element, but sometimes it points to a later
/// message in the list.  See cause_errthrow().
typedef struct msglist msglist_T;
struct msglist {
  msglist_T *next;  ///< next of several messages in a row
  char *msg;        ///< original message, allocated
  char *throw_msg;  ///< msg to throw: usually original one
  char *sfile;      ///< value from estack_sfile(), allocated
  linenr_T slnum;   ///< line number for "sfile"
  bool multiline;   ///< whether this is a multiline message
};

/// The exception types.
typedef enum {
  ET_USER,       ///< exception caused by ":throw" command
  ET_ERROR,      ///< error exception
  ET_INTERRUPT,  ///< interrupt exception triggered by Ctrl-C
} except_type_T;

/// Structure describing an exception.
/// (don't use "struct exception", it's used by the math library).
typedef struct vim_exception except_T;
struct vim_exception {
  except_type_T type;   ///< exception type
  char *value;          ///< exception value
  msglist_T *messages;  ///< message(s) causing error exception
  char *throw_name;     ///< name of the throw point
  linenr_T throw_lnum;  ///< line number of the throw point
  except_T *caught;     ///< next exception on the caught stack
};

/// Structure to save the error/interrupt/exception state between calls to
/// enter_cleanup() and leave_cleanup().  Must be allocated as an automatic
/// variable by the (common) caller of these functions.
typedef struct cleanup_stuff cleanup_T;
struct cleanup_stuff {
  int pending;          ///< error/interrupt/exception state
  except_T *exception;  ///< exception value
};

/// Exception state that is saved and restored when calling timer callback
/// functions and deferred functions.
typedef struct exception_state_S exception_state_T;
struct exception_state_S {
  except_T *estate_current_exception;
  bool estate_did_throw;
  bool estate_need_rethrow;
  int estate_trylevel;
  int estate_did_emsg;
};