// vim: ts=4 sw=4 expandtab ft=c

// Copyright (C) 1998-2000,2002-2003, 2005-2007 The University of Melbourne.
// Copyright (C) 2016, 2018 The Mercury team.
// This file is distributed under the terms specified in COPYING.LIB.

// mercury_trace_alias.c - implements the table of aliases for the
// internal debugger.
//
// Author: zs.

#include "mercury_imp.h"
#include "mercury_array_macros.h"

#include "mercury_trace_alias.h"
#include "mercury_trace_util.h"

static  MR_Alias    *MR_alias_records = NULL;
static  int         MR_alias_record_max = 0;
static  int         MR_alias_record_next = 0;

// The initial size of arrays of words.
#define MR_INIT_WORD_COUNT  20

// The initial size of the alias table.
#define INIT_ALIAS_COUNT    32

static  void        MR_trace_print_alias_num(FILE *fp, int slot,
                        MR_bool mdb_command_format);
static  char        *MR_trace_get_alias_slot_name(int slot);
static  MR_bool     MR_trace_filter_alias_completions(const char *word,
                        MR_CompleterData *data);

void
MR_trace_add_alias(char *name, char **words, int word_count)
{
    MR_bool found;
    int slot;
    int count;

    MR_bsearch(MR_alias_record_next, slot, found,
        strcmp(MR_alias_records[slot].MR_alias_name, name));
    if (found) {
        count = MR_alias_records[slot].MR_alias_word_count;
        for (int i = 0; i < count; i++) {
            MR_free(MR_alias_records[slot].MR_alias_words[i]);
        }

        MR_free(MR_alias_records[slot].MR_alias_name);
        MR_free(MR_alias_records[slot].MR_alias_words);
    } else {
        MR_ensure_room_for_next(MR_alias_record, MR_Alias, INIT_ALIAS_COUNT);
        MR_prepare_insert_into_sorted(MR_alias_records, MR_alias_record_next,
            slot, strcmp(MR_alias_records[slot].MR_alias_name, name));
    }

    MR_alias_records[slot].MR_alias_name = MR_copy_string(name);
    MR_alias_records[slot].MR_alias_word_count = word_count;
    MR_alias_records[slot].MR_alias_words = MR_NEW_ARRAY(char *, word_count);
    for (int i = 0; i < word_count; i++) {
        MR_alias_records[slot].MR_alias_words[i] = MR_copy_string(words[i]);
    }
}

MR_bool
MR_trace_remove_alias(const char *name)
{
    MR_bool found;
    int     slot;
    int     count;

    MR_bsearch(MR_alias_record_next, slot, found,
        strcmp(MR_alias_records[slot].MR_alias_name, name));
    if (! found) {
        return MR_FALSE;
    } else {
        count = MR_alias_records[slot].MR_alias_word_count;
        for (int i = 0; i < count; i++) {
            MR_free(MR_alias_records[slot].MR_alias_words[i]);
        }

        MR_free(MR_alias_records[slot].MR_alias_name);
        MR_free(MR_alias_records[slot].MR_alias_words);

        for (int i = slot; i < MR_alias_record_next - 1; i++) {
            MR_assign_structure(MR_alias_records[slot],
                MR_alias_records[slot + 1]);
        }

        MR_alias_record_next--;

        return MR_TRUE;
    }
}

MR_bool
MR_trace_lookup_alias(const char *name,
    char ***words_ptr, int *word_count_ptr)
{
    MR_bool found;
    int slot;

    MR_bsearch(MR_alias_record_next, slot, found,
        strcmp(MR_alias_records[slot].MR_alias_name, name));
    if (found) {
        *word_count_ptr = MR_alias_records[slot].MR_alias_word_count;
        *words_ptr = MR_alias_records[slot].MR_alias_words;
        return MR_TRUE;
    } else {
        return MR_FALSE;
    }
}

void
MR_trace_print_alias(FILE *fp, const char *name)
{
    MR_bool found;
    int     slot;

    MR_bsearch(MR_alias_record_next, slot, found,
        strcmp(MR_alias_records[slot].MR_alias_name, name));
    if (found) {
        MR_trace_print_alias_num(fp, slot, MR_FALSE);
    } else {
        fprintf(fp, "There is no such alias.\n");
    }
}

void
MR_trace_print_all_aliases(FILE *fp, MR_bool mdb_command_format)
{
    for (int slot = 0; slot < MR_alias_record_next; slot++) {
        MR_trace_print_alias_num(fp, slot, mdb_command_format);
    }
}

static void
MR_trace_print_alias_num(FILE *fp, int slot, MR_bool mdb_command_format)
{
    if (mdb_command_format) {
        fprintf(fp, "alias %s", MR_alias_records[slot].MR_alias_name);
    } else {
        fprintf(fp, "%-6s =>   ", MR_alias_records[slot].MR_alias_name);
    }

    for (int i = 0; i < MR_alias_records[slot].MR_alias_word_count; i++) {
        fprintf(fp, " %s", MR_alias_records[slot].MR_alias_words[i]);
    }

    fprintf(fp, "\n");
}

MR_CompleterList *
MR_trace_alias_completer(const char *word, size_t word_length)
{
    // Remove "EMPTY" and "NUMBER" from the possible matches.

    return MR_trace_filter_completer(MR_trace_filter_alias_completions,
        NULL, MR_trace_no_free,
        MR_trace_sorted_array_completer(word, word_length,
            MR_alias_record_next, MR_trace_get_alias_slot_name));
}

static char *
MR_trace_get_alias_slot_name(int slot)
{
    return MR_alias_records[slot].MR_alias_name;
}

static MR_bool
MR_trace_filter_alias_completions(const char *word, MR_CompleterData *data)
{
    return (MR_strdiff(word, "EMPTY") && MR_strdiff(word, "NUMBER"));
}

void
MR_trace_expand_aliases(char ***words, int *word_max, int *word_count)
{
    const char  *alias_key;
    char        **alias_words;
    int         alias_word_count;
    int         alias_copy_start;
    MR_Unsigned n;

    if (*word_count == 0) {
        alias_key = "EMPTY";
        alias_copy_start = 0;
    } else if (MR_trace_is_natural_number(*words[0], &n)) {
        alias_key = "NUMBER";
        alias_copy_start = 0;
    } else {
        alias_key = *words[0];
        alias_copy_start = 1;
    }

    if (MR_trace_lookup_alias(alias_key, &alias_words, &alias_word_count)) {
        MR_ensure_big_enough(*word_count + alias_word_count, *word, char *,
            MR_INIT_WORD_COUNT);

        // Move the original words (except the alias key) up.
        for (int i = *word_count - 1; i >= alias_copy_start; i--) {
            (*words)[i + alias_word_count - alias_copy_start] = (*words)[i];
        }

        // Move the alias body to the words array.
        for (int i = 0; i < alias_word_count; i++) {
            (*words)[i] = alias_words[i];
        }

        *word_count += alias_word_count - alias_copy_start;
    }
}
