/* Copyright (c) 2002-2018 Pigeonhole authors, see the included COPYING file

 */

#include "lib.h"

#include "str.h"

#include "str-sanitize.h"

#include "mail-storage.h"

#include "imap-arg.h"

#include "sieve-common.h"

#include "sieve-commands.h"

#include "sieve-code.h"

#include "sieve-stringlist.h"

#include "sieve-actions.h"

#include "sieve-validator.h"

#include "sieve-generator.h"

#include "sieve-interpreter.h"

#include "sieve-result.h"

#include "sieve-dump.h"

#include "sieve-ext-variables.h"

#include "ext-imap4flags-common.h"

/*

 * Tagged arguments

 */

extern const struct sieve_argument_def tag_flags;

extern const struct sieve_argument_def tag_flags_implicit;

/*

 * Common command functions

 */

bool ext_imap4flags_command_validate(struct sieve_validator *valdtr,

             struct sieve_command *cmd)

{

  const struct sieve_extension *ext = cmd->ext;

  struct ext_imap4flags_context *extctx = ext->context;

  const struct sieve_extension *var_ext = extctx->var_ext;

  struct sieve_ast_argument *arg = cmd->first_positional;

  struct sieve_ast_argument *arg2;

  /* Check arguments */

  if (arg == NULL) {

    sieve_command_validate_error(

      valdtr, cmd,

      "the %s %s expects at least one argument, "

      "but none was found",

      sieve_command_identifier(cmd),

      sieve_command_type_name(cmd));

    return FALSE;

  }

  if (sieve_ast_argument_type(arg) != SAAT_STRING &&

      sieve_ast_argument_type(arg) != SAAT_STRING_LIST) {

    sieve_argument_validate_error(

      valdtr, arg,

      "the %s %s expects either a string (variable name) or "

      "a string-list (list of flags) as first argument, "

      "but %s was found",

      sieve_command_identifier(cmd),

      sieve_command_type_name(cmd),

      sieve_ast_argument_name(arg));

    return FALSE;

  }

  arg2 = sieve_ast_argument_next(arg);

  if (arg2 != NULL) {

    /* First, check syntax sanity */

    if (sieve_ast_argument_type(arg) != SAAT_STRING) {

      if (sieve_command_is(cmd, tst_hasflag)) {

        if (sieve_ast_argument_type(arg) != SAAT_STRING_LIST) {

          sieve_argument_validate_error(

            valdtr, arg,

            "if a second argument is specified for the hasflag, "

            "the first must be a string-list (variable-list), "

            "but %s was found",

            sieve_ast_argument_name(arg));

          return FALSE;

        }

      } else {

        sieve_argument_validate_error(

          valdtr, arg,

          "if a second argument is specified for the %s %s, "

          "the first must be a string (variable name), "

          "but %s was found",

          sieve_command_identifier(cmd),

          sieve_command_type_name(cmd),

          sieve_ast_argument_name(arg));

        return FALSE;

      }

    }

    /* Then, check whether the second argument is permitted */

    if (var_ext == NULL ||

        !sieve_ext_variables_is_active(var_ext, valdtr)) {

      sieve_argument_validate_error(

        valdtr,arg,

        "the %s %s only allows for the specification of a "

        "variable name when the variables extension is active",

        sieve_command_identifier(cmd),

        sieve_command_type_name(cmd));

      return FALSE;

    }

    if (!sieve_variable_argument_activate(

      var_ext, var_ext, valdtr, cmd, arg,

      !sieve_command_is(cmd, tst_hasflag)))

      return FALSE;

    if (sieve_ast_argument_type(arg2) != SAAT_STRING &&

        sieve_ast_argument_type(arg2) != SAAT_STRING_LIST) {

      sieve_argument_validate_error(

        valdtr, arg2,

        "the %s %s expects a string list (list of flags) as "

        "second argument when two arguments are specified, "

        "but %s was found",

        sieve_command_identifier(cmd),

        sieve_command_type_name(cmd),

        sieve_ast_argument_name(arg2));

      return FALSE;

    }

  } else

    arg2 = arg;

  if (!sieve_validator_argument_activate(valdtr, cmd, arg2, FALSE))

    return FALSE;

  if (!sieve_command_is(cmd, tst_hasflag) &&

      sieve_argument_is_string_literal(arg2)) {

    struct ext_imap4flags_iter fiter;

    const char *flag;

    /* Warn the user about validity of verifiable flags */

    ext_imap4flags_iter_init(&fiter, sieve_ast_argument_str(arg));

    while ((flag = ext_imap4flags_iter_get_flag(&fiter)) != NULL) {

      if (!sieve_ext_imap4flags_flag_is_valid(flag)) {

        sieve_argument_validate_warning(

          valdtr, arg,

          "IMAP flag '%s' specified for the %s command is invalid "

          "and will be ignored (only first invalid is reported)",

          str_sanitize(flag, 64),

          sieve_command_identifier(cmd));

        break;

      }

    }

  }

  return TRUE;

}

/*

 * Flags tag registration

 */

void ext_imap4flags_attach_flags_tag(struct sieve_validator *valdtr,

             const struct sieve_extension *ext,

             const char *command)

{

  /* Register :flags tag with the command and we don't care whether it is

     registered or even whether it will be registered at all. The

     validator handles either situation gracefully.

   */

  /* Tag specified by user */

  sieve_validator_register_external_tag(valdtr, command, ext, &tag_flags,

                SIEVE_OPT_SIDE_EFFECT);

}

void sieve_ext_imap4flags_register_side_effect(

  struct sieve_validator *valdtr, const struct sieve_extension *flg_ext,

  const char *command)

{

  /* Implicit tag if none is specified */

  sieve_validator_register_persistent_tag(valdtr, command, flg_ext,

            &tag_flags_implicit);

}

/*

 * Result context

 */

struct ext_imap4flags_result_context {

    string_t *internal_flags;

};

static void _get_initial_flags(struct sieve_result *result, string_t *flags)

{

  const struct sieve_message_data *msgdata =

    sieve_result_get_message_data(result);

  enum mail_flags mail_flags;

  const char *const *mail_keywords;

  mail_flags = mail_get_flags(msgdata->mail);

  mail_keywords = mail_get_keywords(msgdata->mail);

  if ((mail_flags & MAIL_FLAGGED) > 0)

    str_printfa(flags, " \\flagged");

  if ((mail_flags & MAIL_ANSWERED) > 0)

    str_printfa(flags, " \\answered");

  if ((mail_flags & MAIL_DELETED) > 0)

    str_printfa(flags, " \\deleted");

  if ((mail_flags & MAIL_SEEN) > 0)

    str_printfa(flags, " \\seen");

  if ((mail_flags & MAIL_DRAFT) > 0)

    str_printfa(flags, " \\draft");

  while (*mail_keywords != NULL) {

    str_printfa(flags, " %s", *mail_keywords);

    mail_keywords++;

  }

}

static inline struct ext_imap4flags_result_context *

_get_result_context(const struct sieve_extension *this_ext,

        struct sieve_result *result)

{

  struct ext_imap4flags_result_context *rctx =

    (struct ext_imap4flags_result_context *)

      sieve_result_extension_get_context(result, this_ext);

  if (rctx == NULL) {

    pool_t pool = sieve_result_pool(result);

    rctx = p_new(pool, struct ext_imap4flags_result_context, 1);

    rctx->internal_flags = str_new(pool, 32);

    _get_initial_flags(result, rctx->internal_flags);

    sieve_result_extension_set_context(result, this_ext, rctx);

  }

  return rctx;

}

static string_t *

_get_flags_string(const struct sieve_extension *this_ext,

      struct sieve_result *result)

{

  struct ext_imap4flags_result_context *ctx =

    _get_result_context(this_ext, result);

  return ctx->internal_flags;

}

/*

 * Runtime initialization

 */

static int

ext_imap4flags_runtime_init(const struct sieve_extension *ext,

          const struct sieve_runtime_env *renv,

          void *context ATTR_UNUSED,

          bool deferred ATTR_UNUSED)

{

  sieve_result_add_implicit_side_effect(renv->result, NULL, TRUE, ext,

                &flags_side_effect, NULL);

  return SIEVE_EXEC_OK;

}

const struct sieve_interpreter_extension

imap4flags_interpreter_extension = {

  .ext_def = &imap4flags_extension,

  .run = ext_imap4flags_runtime_init,

};

/*

 * Flag handling

 */

/* FIXME: This currently accepts a potentially unlimited number of flags, making

          the internal or variable flag list indefinitely long.

 */

bool sieve_ext_imap4flags_flag_is_valid(const char *flag)

{

  if (*flag == '\0')

    return FALSE;

  if (*flag == '\\') {

    /* System flag */

    const char *atom = t_str_ucase(flag);

    if (strcmp(atom, "\\ANSWERED") != 0 &&

        strcmp(atom, "\\FLAGGED") != 0 &&

        strcmp(atom, "\\DELETED") != 0 &&

        strcmp(atom, "\\SEEN") != 0 &&

        strcmp(atom, "\\DRAFT") != 0)

    {

      return FALSE;

    }

  } else {

    const char *p;

    /* Custom keyword:

       Syntax (IMAP4rev1, RFC 3501, Section 9. Formal Syntax) :

        flag-keyword    = atom

        atom            = 1*ATOM-CHAR

     */

    p = flag;

    while (*p != '\0') {

      if (!IS_ATOM_CHAR(*p))

        return FALSE;

      p++;

    }

  }

  return TRUE;

}

/* Flag iterator */

static void ext_imap4flags_iter_clear(struct ext_imap4flags_iter *iter)

{

  i_zero(iter);

}

void ext_imap4flags_iter_init(struct ext_imap4flags_iter *iter,

            string_t *flags_list)

{

  ext_imap4flags_iter_clear(iter);

  iter->flags_list = flags_list;

}

static string_t *

ext_imap4flags_iter_get_flag_str(struct ext_imap4flags_iter *iter)

{

  unsigned int len;

  const unsigned char *fp;

  const unsigned char *fbegin;

  const unsigned char *fstart;

  const unsigned char *fend;

  /* Return if not initialized */

  if (iter->flags_list == NULL)

    return NULL;

  /* Return if no more flags are available */

  len = str_len(iter->flags_list);

  if (iter->offset >= len)

    return NULL;

  /* Mark string boundries */

  fbegin = str_data(iter->flags_list);

  fend = fbegin + len;

  /* Start of this flag */

  fstart = fbegin + iter->offset;

  /* Scan for next flag */

  fp = fstart;

  for (;;) {

    /* Have we reached the end or a flag boundary? */

    if (fp >= fend || *fp == ' ') {

      /* Did we scan more than nothing ? */

      if (fp > fstart) {

        /* Return flag */

        string_t *flag = t_str_new(fp-fstart+1);

        str_append_data(flag, fstart, fp-fstart);

        iter->last = fstart - fbegin;

        iter->offset = fp - fbegin;

        return flag;

      }

      fstart = fp + 1;

    }

    if (fp >= fend)

      break;

    fp++;

  }

  iter->last = fstart - fbegin;

  iter->offset = fp - fbegin;

  return NULL;

}

const char *ext_imap4flags_iter_get_flag(struct ext_imap4flags_iter *iter)

{

  string_t *flag = ext_imap4flags_iter_get_flag_str(iter);

  if (flag == NULL)

    return NULL;

  return str_c(flag);

}

static void ext_imap4flags_iter_delete_last(struct ext_imap4flags_iter *iter)

{

  iter->offset++;

  if (iter->offset > str_len(iter->flags_list))

    iter->offset = str_len(iter->flags_list);

  if (iter->offset == str_len(iter->flags_list) && iter->last > 0)

    iter->last--;

  str_delete(iter->flags_list, iter->last, iter->offset - iter->last);

  iter->offset = iter->last;

}

/* Flag operations */

static string_t *

ext_imap4flags_get_flag_variable(const struct sieve_runtime_env *renv,

         const struct sieve_extension *flg_ext,

         struct sieve_variable_storage *storage,

         unsigned int var_index) ATTR_NULL(2);

static bool flags_list_flag_exists(string_t *flags_list, const char *flag)

{

  const char *flg;

  struct ext_imap4flags_iter flit;

  ext_imap4flags_iter_init(&flit, flags_list);

  while ((flg = ext_imap4flags_iter_get_flag(&flit)) != NULL) {

    if (strcasecmp(flg, flag) == 0)

      return TRUE;

  }

  return FALSE;

}

static void flags_list_flag_delete(string_t *flags_list, const char *flag)

{

  const char *flg;

  struct ext_imap4flags_iter flit;

  ext_imap4flags_iter_init(&flit, flags_list);

  while ((flg = ext_imap4flags_iter_get_flag(&flit)) != NULL) {

    if (strcasecmp(flg, flag) == 0)

      ext_imap4flags_iter_delete_last(&flit);

  }

}

static void flags_list_add_flags(string_t *flags_list, string_t *flags)

{

  const char *flg;

  struct ext_imap4flags_iter flit;

  ext_imap4flags_iter_init(&flit, flags);

  while ((flg = ext_imap4flags_iter_get_flag(&flit)) != NULL) {

    if (sieve_ext_imap4flags_flag_is_valid(flg) &&

        !flags_list_flag_exists(flags_list, flg)) {

      if (str_len(flags_list) != 0)

        str_append_c(flags_list, ' ');

      str_append(flags_list, flg);

    }

  }

}

static void flags_list_remove_flags(string_t *flags_list, string_t *flags)

{

  const char *flg;

  struct ext_imap4flags_iter flit;

  ext_imap4flags_iter_init(&flit, flags);

  while ((flg = ext_imap4flags_iter_get_flag(&flit)) != NULL)

    flags_list_flag_delete(flags_list, flg);

}

static void flags_list_set_flags(string_t *flags_list, string_t *flags)

{

  str_truncate(flags_list, 0);

  flags_list_add_flags(flags_list, flags);

}

static void flags_list_clear_flags(string_t *flags_list)

{

  str_truncate(flags_list, 0);

}

static string_t *

ext_imap4flags_get_flag_variable(const struct sieve_runtime_env *renv,

         const struct sieve_extension *flg_ext,

         struct sieve_variable_storage *storage,

         unsigned int var_index)

{

  string_t *flags;

  if (storage != NULL) {

    if (sieve_runtime_trace_active(renv, SIEVE_TRLVL_COMMANDS)) {

      const char *var_name, *var_id;

      (void)sieve_variable_get_identifier(storage, var_index,

                  &var_name);

      var_id = sieve_variable_get_varid(storage, var_index);

      sieve_runtime_trace(renv, 0,

              "update variable '%s' [%s]",

              var_name, var_id);

    }

    if (!sieve_variable_get_modifiable(storage, var_index, &flags))

      return NULL;

  } else {

    i_assert(sieve_extension_is(flg_ext, imap4flags_extension));

    flags = _get_flags_string(flg_ext, renv->result);

  }

  return flags;

}

int sieve_ext_imap4flags_set_flags(const struct sieve_runtime_env *renv,

           const struct sieve_extension *flg_ext,

           struct sieve_variable_storage *storage,

           unsigned int var_index,

           struct sieve_stringlist *flags)

{

  string_t *cur_flags = ext_imap4flags_get_flag_variable(

    renv, flg_ext, storage, var_index);

  if (cur_flags != NULL) {

    string_t *flags_item;

    int ret;

    flags_list_clear_flags(cur_flags);

    while ((ret = sieve_stringlist_next_item(

      flags, &flags_item)) > 0) {

      sieve_runtime_trace(renv, SIEVE_TRLVL_COMMANDS,

              "set flags '%s'",

              str_c(flags_item));

      flags_list_add_flags(cur_flags, flags_item);

    }

    if (ret < 0)

      return SIEVE_EXEC_BIN_CORRUPT;

    return SIEVE_EXEC_OK;

  }

  return SIEVE_EXEC_BIN_CORRUPT;

}

int sieve_ext_imap4flags_add_flags(const struct sieve_runtime_env *renv,

           const struct sieve_extension *flg_ext,

           struct sieve_variable_storage *storage,

           unsigned int var_index,

           struct sieve_stringlist *flags)

{

  string_t *cur_flags = ext_imap4flags_get_flag_variable(

    renv, flg_ext, storage, var_index);

  if (cur_flags != NULL) {

    string_t *flags_item;

    int ret;

    while ((ret = sieve_stringlist_next_item(

      flags, &flags_item)) > 0) {

      sieve_runtime_trace(renv, SIEVE_TRLVL_COMMANDS,

              "add flags '%s'",

              str_c(flags_item));

      flags_list_add_flags(cur_flags, flags_item);

    }

    if (ret < 0)

      return SIEVE_EXEC_BIN_CORRUPT;

    return SIEVE_EXEC_OK;

  }

  return SIEVE_EXEC_BIN_CORRUPT;

}

int sieve_ext_imap4flags_remove_flags(const struct sieve_runtime_env *renv,

              const struct sieve_extension *flg_ext,

              struct sieve_variable_storage *storage,

              unsigned int var_index,

              struct sieve_stringlist *flags)

{

  string_t *cur_flags = ext_imap4flags_get_flag_variable(

    renv, flg_ext, storage, var_index);

  if (cur_flags != NULL) {

    string_t *flags_item;

    int ret;

    while ((ret = sieve_stringlist_next_item(

      flags, &flags_item)) > 0) {

      sieve_runtime_trace(renv, SIEVE_TRLVL_COMMANDS,

              "remove flags '%s'",

              str_c(flags_item));

      flags_list_remove_flags(cur_flags, flags_item);

    }

    if (ret < 0) return

      SIEVE_EXEC_BIN_CORRUPT;

    return SIEVE_EXEC_OK;

  }

  return SIEVE_EXEC_BIN_CORRUPT;

}

/* Flag stringlist */

static int

ext_imap4flags_stringlist_next_item(struct sieve_stringlist *_strlist,

            string_t **str_r);

static void

ext_imap4flags_stringlist_reset(struct sieve_stringlist *_strlist);

struct ext_imap4flags_stringlist {

  struct sieve_stringlist strlist;

  struct sieve_stringlist *flags_list;

  string_t *flags_string;

  struct ext_imap4flags_iter flit;

  bool normalize:1;

};

static struct sieve_stringlist *

ext_imap4flags_stringlist_create(const struct sieve_runtime_env *renv,

         struct sieve_stringlist *flags_list,

         bool normalize)

{

  struct ext_imap4flags_stringlist *strlist;

  strlist = t_new(struct ext_imap4flags_stringlist, 1);

  strlist->strlist.exec_status = SIEVE_EXEC_OK;

  strlist->strlist.runenv = renv;

  strlist->strlist.next_item = ext_imap4flags_stringlist_next_item;

  strlist->strlist.reset = ext_imap4flags_stringlist_reset;

  strlist->normalize = normalize;

  strlist->flags_list = flags_list;

  return &strlist->strlist;

}

static struct sieve_stringlist *

ext_imap4flags_stringlist_create_single(const struct sieve_runtime_env *renv,

          string_t *flags_string, bool normalize)

{

  struct ext_imap4flags_stringlist *strlist;

  strlist = t_new(struct ext_imap4flags_stringlist, 1);

  strlist->strlist.exec_status = SIEVE_EXEC_OK;

  strlist->strlist.runenv = renv;

  strlist->strlist.next_item = ext_imap4flags_stringlist_next_item;

  strlist->strlist.reset = ext_imap4flags_stringlist_reset;

  strlist->normalize = normalize;

  if (normalize) {

    strlist->flags_string = t_str_new(256);

    flags_list_set_flags(strlist->flags_string, flags_string);

  } else {

    strlist->flags_string = flags_string;

  }

  ext_imap4flags_iter_init(&strlist->flit, strlist->flags_string);

  return &strlist->strlist;

}

static int

ext_imap4flags_stringlist_next_item(struct sieve_stringlist *_strlist,

            string_t **str_r)

{

  struct ext_imap4flags_stringlist *strlist =

    (struct ext_imap4flags_stringlist *)_strlist;

  while ((*str_r = ext_imap4flags_iter_get_flag_str(

    &strlist->flit)) == NULL) {

    int ret;

    if (strlist->flags_list == NULL)

      return 0;

    ret = sieve_stringlist_next_item(strlist->flags_list,

             &strlist->flags_string);

    if (ret <= 0)

      return ret;

    if (strlist->flags_string == NULL)

      return -1;

    if (strlist->normalize) {

      string_t *flags_string = t_str_new(256);

      flags_list_set_flags(flags_string,

               strlist->flags_string);

      strlist->flags_string = flags_string;

    }

    ext_imap4flags_iter_init(&strlist->flit, strlist->flags_string);

  }

  return 1;

}

static void ext_imap4flags_stringlist_reset(struct sieve_stringlist *_strlist)

{

  struct ext_imap4flags_stringlist *strlist =

    (struct ext_imap4flags_stringlist *)_strlist;

  if (strlist->flags_list != NULL) {

    sieve_stringlist_reset(strlist->flags_list);

    ext_imap4flags_iter_clear(&strlist->flit);

  } else {

    ext_imap4flags_iter_init(&strlist->flit, strlist->flags_string);

  }

}

/* Flag access */

struct sieve_stringlist *

sieve_ext_imap4flags_get_flags(const struct sieve_runtime_env *renv,

             const struct sieve_extension *flg_ext,

             struct sieve_stringlist *flags_list)

{

  if (flags_list == NULL) {

    i_assert(sieve_extension_is(flg_ext, imap4flags_extension));

    return ext_imap4flags_stringlist_create_single(

      renv, _get_flags_string(flg_ext, renv->result), FALSE);

  }

  return ext_imap4flags_stringlist_create(renv, flags_list, TRUE);

}

void ext_imap4flags_get_implicit_flags_init(

  struct ext_imap4flags_iter *iter,

  const struct sieve_extension *this_ext, struct sieve_result *result)

{

  string_t *cur_flags = _get_flags_string(this_ext, result);

  ext_imap4flags_iter_init(iter, cur_flags);

}