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

 */

#include "lib.h"

#include "str-sanitize.h"

#include "mail-storage.h"

#include "rfc2822.h"

#include "edit-mail.h"

#include "sieve-common.h"

#include "sieve-commands.h"

#include "sieve-code.h"

#include "sieve-message.h"

#include "sieve-comparators.h"

#include "sieve-match-types.h"

#include "sieve-validator.h"

#include "sieve-generator.h"

#include "sieve-interpreter.h"

#include "sieve-dump.h"

#include "sieve-match.h"

#include "ext-editheader-common.h"

/*

 * Deleteheader command

 *

 * Syntax:

 *   deleteheader [":index" <fieldno: number> [":last"]]

 *                [COMPARATOR] [MATCH-TYPE]

 *                <field-name: string> [<value-patterns: string-list>]

 */

static bool

cmd_deleteheader_registered(struct sieve_validator *valdtr,

          const struct sieve_extension *ext,

          struct sieve_command_registration *cmd_reg);

static bool

cmd_deleteheader_validate(struct sieve_validator *valdtr,

        struct sieve_command *cmd);

static bool

cmd_deleteheader_generate(const struct sieve_codegen_env *cgenv,

        struct sieve_command *cmd);

const struct sieve_command_def deleteheader_command = {

  .identifier = "deleteheader",

  .type = SCT_COMMAND,

  .positional_args = -1, /* We check positional arguments ourselves */

  .subtests = 0,

  .block_allowed = FALSE,

  .block_required = FALSE,

  .registered = cmd_deleteheader_registered,

  .validate = cmd_deleteheader_validate,

  .generate = cmd_deleteheader_generate,

};

/*

 * Deleteheader command tags

 */

/* Forward declarations */

static bool

cmd_deleteheader_validate_index_tag(struct sieve_validator *valdtr,

            struct sieve_ast_argument **arg,

            struct sieve_command *cmd);

static bool

cmd_deleteheader_validate_last_tag(struct sieve_validator *valdtr,

           struct sieve_ast_argument **arg,

           struct sieve_command *cmd);

/* Argument objects */

static const struct sieve_argument_def deleteheader_index_tag = {

  .identifier = "index",

  .validate = cmd_deleteheader_validate_index_tag,

};

static const struct sieve_argument_def deleteheader_last_tag = {

  .identifier = "last",

  .validate = cmd_deleteheader_validate_last_tag,

};

/* Codes for optional arguments */

enum cmd_deleteheader_optional {

  OPT_INDEX = SIEVE_MATCH_OPT_LAST,

  OPT_LAST,

};

/*

 * Deleteheader operation

 */

static bool

cmd_deleteheader_operation_dump(const struct sieve_dumptime_env *denv,

        sieve_size_t *address);

static int

cmd_deleteheader_operation_execute(const struct sieve_runtime_env *renv,

           sieve_size_t *address);

const struct sieve_operation_def deleteheader_operation = {

  .mnemonic = "DELETEHEADER",

  .ext_def = &editheader_extension,

  .code = EXT_EDITHEADER_OPERATION_DELETEHEADER,

  .dump = cmd_deleteheader_operation_dump,

  .execute = cmd_deleteheader_operation_execute,

};

/*

 * Command registration

 */

static bool

cmd_deleteheader_registered(struct sieve_validator *valdtr,

          const struct sieve_extension *ext ATTR_UNUSED,

          struct sieve_command_registration *cmd_reg)

{

  /* The order of these is not significant */

  sieve_comparators_link_tag(valdtr, cmd_reg,

           SIEVE_MATCH_OPT_COMPARATOR);

  sieve_match_types_link_tags(valdtr, cmd_reg,

            SIEVE_MATCH_OPT_MATCH_TYPE);

  sieve_validator_register_tag(valdtr, cmd_reg, ext,

             &deleteheader_index_tag, OPT_INDEX);

  sieve_validator_register_tag(valdtr, cmd_reg, ext,

             &deleteheader_last_tag, OPT_LAST);

  return TRUE;

}

/*

 * Command validation context

 */

struct cmd_deleteheader_context_data {

  struct sieve_ast_argument *arg_index;

  struct sieve_ast_argument *arg_last;

};

/*

 * Tag validation

 */

static struct cmd_deleteheader_context_data *

cmd_deleteheader_get_context(struct sieve_command *cmd)

{

  struct cmd_deleteheader_context_data *ctx_data =

    (struct cmd_deleteheader_context_data *)cmd->data;

  if (ctx_data != NULL)

    return ctx_data;

  ctx_data = p_new(sieve_command_pool(cmd),

       struct cmd_deleteheader_context_data, 1);

  cmd->data = ctx_data;

  return ctx_data;

}

static bool

cmd_deleteheader_validate_index_tag(struct sieve_validator *valdtr,

            struct sieve_ast_argument **arg,

            struct sieve_command *cmd)

{

  struct sieve_ast_argument *tag = *arg;

  struct cmd_deleteheader_context_data *ctx_data;

  sieve_number_t index;

  /* Detach the tag itself */

  *arg = sieve_ast_arguments_detach(*arg,1);

  /* Check syntax:

   *   :index number

   */

  if (!sieve_validate_tag_parameter(valdtr, cmd, tag, *arg, NULL, 0,

            SAAT_NUMBER, FALSE))

    return FALSE;

  index = sieve_ast_argument_number(*arg);

  if (index > INT_MAX) {

    sieve_argument_validate_warning(

      valdtr, *arg,

      "the :%s tag for the %s %s has a parameter value '%llu' "

      "exceeding the maximum (%d)",

      sieve_argument_identifier(tag),

      sieve_command_identifier(cmd),

      sieve_command_type_name(cmd),

      (unsigned long long)index, INT_MAX);

    return FALSE;

  }

  ctx_data = cmd_deleteheader_get_context(cmd);

  ctx_data->arg_index = *arg;

  /* Skip parameter */

  *arg = sieve_ast_argument_next(*arg);

  return TRUE;

}

static bool

cmd_deleteheader_validate_last_tag(struct sieve_validator *valdtr ATTR_UNUSED,

           struct sieve_ast_argument **arg,

           struct sieve_command *cmd)

{

  struct cmd_deleteheader_context_data *ctx_data;

  ctx_data = cmd_deleteheader_get_context(cmd);

  ctx_data->arg_last = *arg;

  /* Skip parameter */

  *arg = sieve_ast_argument_next(*arg);

  return TRUE;

}

/*

 * Validation

 */

static bool

cmd_deleteheader_validate(struct sieve_validator *valdtr,

        struct sieve_command *cmd)

{

  struct sieve_ast_argument *arg = cmd->first_positional;

  struct cmd_deleteheader_context_data *ctx_data =

    (struct cmd_deleteheader_context_data *)cmd->data;

  struct sieve_comparator cmp_default =

    SIEVE_COMPARATOR_DEFAULT(i_ascii_casemap_comparator);

  struct sieve_match_type mcht_default =

    SIEVE_MATCH_TYPE_DEFAULT(is_match_type);

  if (ctx_data != NULL &&

      ctx_data->arg_last != NULL && ctx_data->arg_index == NULL) {

    sieve_argument_validate_error(

      valdtr, ctx_data->arg_last,

      "the :last tag for the %s %s cannot be specified "

      "without the :index tag",

      sieve_command_identifier(cmd),

      sieve_command_type_name(cmd));

    return FALSE;

  }

  /* Field name argument */

  if (arg == NULL) {

    sieve_command_validate_error(

      valdtr, cmd,

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

      "but none was found",

      sieve_command_identifier(cmd),

      sieve_command_type_name(cmd));

    return FALSE;

  }

  if (!sieve_validate_positional_argument(valdtr, cmd, arg, "field name",

            1, SAAT_STRING_LIST))

    return FALSE;

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

    return FALSE;

  if (sieve_argument_is_string_literal(arg)) {

    string_t *fname = sieve_ast_argument_str(arg);

    if (!rfc2822_header_field_name_verify(str_c(fname),

                  str_len(fname))) {

      sieve_argument_validate_error(

        valdtr, arg, "deleteheader command:"

        "specified field name '%s' is invalid",

        str_sanitize(str_c(fname), 80));

      return FALSE;

    }

    if (!ext_editheader_header_allow_delete(

      cmd->ext, str_c(fname))) {

      sieve_argument_validate_warning(

        valdtr, arg, "deleteheader command: "

        "deleting specified header field '%s' is forbidden; "

        "modification will be denied",

        str_sanitize(str_c(fname), 80));

    }

  }

  /* Value patterns argument */

  arg = sieve_ast_argument_next(arg);

  if (arg == NULL) {

    /* There is none; let's not generate code for useless match

       arguments */

    sieve_match_type_arguments_remove(valdtr, cmd);

    return TRUE;

  }

  if (!sieve_validate_positional_argument(

    valdtr, cmd, arg, "value patterns", 2, SAAT_STRING_LIST))

    return FALSE;

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

    return FALSE;

  /* Validate the value patterns to a specified match type */

  return sieve_match_type_validate(valdtr, cmd, arg,

           &mcht_default, &cmp_default);

}

/*

 * Code generation

 */

static bool

cmd_deleteheader_generate(const struct sieve_codegen_env *cgenv,

        struct sieve_command *cmd)

{

  sieve_operation_emit(cgenv->sblock, cmd->ext, &deleteheader_operation);

  /* Generate arguments */

  if (!sieve_generate_arguments(cgenv, cmd, NULL))

    return FALSE;

  /* Emit a placeholder when the value-patterns argument is missing */

  if (sieve_ast_argument_next(cmd->first_positional) == NULL)

    sieve_opr_omitted_emit(cgenv->sblock);

  return TRUE;

}

/*

 * Code dump

 */

static bool

cmd_deleteheader_operation_dump(const struct sieve_dumptime_env *denv,

        sieve_size_t *address)

{

  int opt_code = 0;

  sieve_code_dumpf(denv, "DELETEHEADER");

  sieve_code_descend(denv);

  /* Optional operands */

  for (;;) {

    int opt;

    opt = sieve_match_opr_optional_dump(denv, address, &opt_code);

    if (opt < 0)

      return FALSE;

    if (opt == 0)

      break;

    switch (opt_code) {

    case OPT_INDEX:

      if (!sieve_opr_number_dump(denv, address, "index"))

        return FALSE;

      break;

    case OPT_LAST:

      sieve_code_dumpf(denv, "last");

      break;

    default:

      return FALSE;

    }

  };

  if (!sieve_opr_string_dump(denv, address, "field name"))

    return FALSE;

  return sieve_opr_stringlist_dump_ex(

    denv, address, "value patterns", "");

}

/*

 * Code execution

 */

static int

cmd_deleteheader_operation_execute(const struct sieve_runtime_env *renv,

           sieve_size_t *address)

{

  const struct sieve_extension *this_ext = renv->oprtn->ext;

  int opt_code = 0;

  struct sieve_comparator cmp =

    SIEVE_COMPARATOR_DEFAULT(i_ascii_casemap_comparator);

  struct sieve_match_type mcht =

    SIEVE_MATCH_TYPE_DEFAULT(is_match_type);

  string_t *field_name;

  struct sieve_stringlist *vpattern_list = NULL;

  struct edit_mail *edmail;

  sieve_number_t index_offset = 0;

  bool index_last = FALSE;

  bool trace = FALSE;

  int ret;

  /*

   * Read operands

   */

  for (;;) {

    int opt;

    opt = sieve_match_opr_optional_read(renv, address, &opt_code,

                &ret, &cmp, &mcht);

    if (opt < 0)

      return ret;

    if (opt == 0)

      break;

    switch (opt_code) {

    case OPT_INDEX:

      ret = sieve_opr_number_read(renv, address, "index",

                &index_offset);

      if (ret <= 0)

        return ret;

      if (index_offset > INT_MAX) {

        sieve_runtime_trace_error(

          renv, "index is > %d", INT_MAX);

        return SIEVE_EXEC_BIN_CORRUPT;

      }

      break;

    case OPT_LAST:

      index_last = TRUE;

      break;

    default:

      sieve_runtime_trace_error(

        renv, "unknown optional operand");

      return SIEVE_EXEC_BIN_CORRUPT;

    }

  }

  /* Read field-name */

  ret = sieve_opr_string_read(renv, address, "field-name", &field_name);

  if (ret <= 0)

    return ret;

  /* Read value-patterns */

  ret = sieve_opr_stringlist_read_ex(renv, address, "value-patterns",

             TRUE, &vpattern_list);

  if (ret <= 0)

    return ret;

  /*

   * Verify arguments

   */

  if (!rfc2822_header_field_name_verify(str_c(field_name),

                str_len(field_name))) {

    sieve_runtime_error(

      renv, NULL, "deleteheader action: "

      "specified field name '%s' is invalid",

      str_sanitize(str_c(field_name), 80));

    return SIEVE_EXEC_FAILURE;

  }

  if (!ext_editheader_header_allow_delete(this_ext, str_c(field_name))) {

    sieve_runtime_warning(

      renv, NULL, "deleteheader action: "

      "deleting specified header field '%s' is forbidden; "

      "modification denied",

      str_sanitize(str_c(field_name), 80));

    return SIEVE_EXEC_OK;

  }

  /*

   * Execute command

   */

  sieve_runtime_trace(renv, SIEVE_TRLVL_COMMANDS, "deleteheader command");

  /* Start editing the mail */

  edmail = sieve_message_edit(renv->msgctx);

  trace = sieve_runtime_trace_active(renv, SIEVE_TRLVL_COMMANDS);

  /* Either do string matching or just kill all/indexed notify action(s)

   */

  if (vpattern_list != NULL) {

    struct edit_mail_header_iter *edhiter;

    struct sieve_match_context *mctx;

    if (trace) {

      sieve_runtime_trace_descend(renv);

      if (index_offset != 0) {

        sieve_runtime_trace(

          renv, 0,

          "deleting matching occurrences of header '%s' at index %llu%s",

          str_c(field_name),

          (unsigned long long)index_offset,

          (index_last ? " from last": ""));

      } else {

        sieve_runtime_trace(

          renv, 0,

          "deleting matching occurrences of header '%s'",

          str_c(field_name));

      }

    }

    /* Iterate through all headers and delete those that match */

    ret = edit_mail_headers_iterate_init(edmail, str_c(field_name),

                 index_last, &edhiter);

    if (ret > 0) {

      int mret = 0;

      sieve_number_t pos = 0;

      /* Initialize match */

      mctx = sieve_match_begin(renv, &mcht, &cmp);

      /* Match */

      for (;;) {

        pos++;

        /* Check index if any */

        if (index_offset == 0 || pos == index_offset) {

          const char *value;

          int match;

          /* Match value against all value patterns */

          edit_mail_headers_iterate_get(edhiter, &value);

          match = sieve_match_value(

            mctx, value, strlen(value),

            vpattern_list);

          if (match < 0)

            break;

          if (match > 0) {

            /* Remove it and iterate to next */

            sieve_runtime_trace(

              renv, 0,

              "deleting header with value '%s'",

              value);

            if (!edit_mail_headers_iterate_remove(edhiter))

              break;

            continue;

          }

        }

        if (!edit_mail_headers_iterate_next(edhiter))

          break;

      }

      /* Finish match */

      mret = sieve_match_end(&mctx, &ret);

      edit_mail_headers_iterate_deinit(&edhiter);

      if (mret < 0)

        return ret;

    }

    if (ret == 0) {

      sieve_runtime_trace(renv, 0, "header '%s' not found",

              str_c(field_name));

    } else if (ret < 0) {

      sieve_runtime_warning(

        renv, NULL, "deleteheader action: "

        "failed to delete occurrences of header '%s' "

        "(this should not happen!)",

        str_c(field_name));

    }

  } else {

    int index = (index_last ?

           -((int)index_offset) : ((int)index_offset));

    if (trace) {

      sieve_runtime_trace_descend(renv);

      if (index_offset != 0) {

        sieve_runtime_trace(

          renv, 0,

          "deleting header '%s' at index %llu%s",

          str_c(field_name),

          (unsigned long long)index_offset,

          (index_last ? " from last": ""));

      } else {

        sieve_runtime_trace(

          renv, 0, "deleting header '%s'",

          str_c(field_name));

      }

    }

    /* Delete all occurrences of header */

    ret = edit_mail_header_delete(edmail, str_c(field_name), index);

    if (ret < 0) {

      sieve_runtime_warning(

        renv, NULL, "deleteheader action: "

        "failed to delete occurrences of header '%s' "

        "(this should not happen!)",

        str_c(field_name));

    } else if (trace) {

      sieve_runtime_trace(

        renv, 0,

        "deleted %d occurrences of header '%s'",

        ret, str_c(field_name));

    }

  }

  return SIEVE_EXEC_OK;

}