// Copyright 2008 Google Inc.  All rights reserved.

#include "gutil/strings/substitute.h"

#include "common/logging.h"

#include <stdint.h>

#include <ostream>

// IWYU pragma: no_include <butil/macros.h>

#include "gutil/macros.h" // IWYU pragma: keep

#include "gutil/stl_util.h"

#include "gutil/strings/ascii_ctype.h"

#include "gutil/strings/escaping.h"

namespace strings {

using internal::SubstituteArg;

const SubstituteArg SubstituteArg::NoArg;

// Returns the number of args in arg_array which were passed explicitly

// to Substitute().

static int CountSubstituteArgs(const SubstituteArg* const* args_array) {

    int count = 0;

    while (args_array[count] != &SubstituteArg::NoArg) {

        ++count;

    }

    return count;

}

namespace internal {

int SubstitutedSize(StringPiece format, const SubstituteArg* const* args_array) {

    int size = 0;

    for (int i = 0; i < format.size(); i++) {

        if (format[i] == '$') {

            if (i + 1 >= format.size()) {

                LOG(DFATAL) << "Invalid strings::Substitute() format string: \"" << CEscape(format)

                            << "\".";

                return 0;

            } else if (ascii_isdigit(format[i + 1])) {

                int index = format[i + 1] - '0';

                if (args_array[index]->size() == -1) {

                    LOG(DFATAL) << "strings::Substitute format string invalid: asked for \"$"

                                << index << "\", but only " << CountSubstituteArgs(args_array)

                                << " args were given.  Full format string was: \""

                                << CEscape(format) << "\".";

                    return 0;

                }

                size += args_array[index]->size();

                ++i; // Skip next char.

            } else if (format[i + 1] == '$') {

                ++size;

                ++i; // Skip next char.

            } else {

                LOG(DFATAL) << "Invalid strings::Substitute() format string: \"" << CEscape(format)

                            << "\".";

                return 0;

            }

        } else {

            ++size;

        }

    }

    return size;

}

char* SubstituteToBuffer(StringPiece format, const SubstituteArg* const* args_array, char* target) {

    for (int i = 0; i < format.size(); i++) {

        if (format[i] == '$') {

            if (ascii_isdigit(format[i + 1])) {

                const SubstituteArg* src = args_array[format[i + 1] - '0'];

                memcpy(target, src->data(), src->size());

                target += src->size();

                ++i; // Skip next char.

            } else if (format[i + 1] == '$') {

                *target++ = '$';

                ++i; // Skip next char.

            }

        } else {

            *target++ = format[i];

        }

    }

    return target;

}

} // namespace internal

void SubstituteAndAppend(string* output, StringPiece format, const SubstituteArg& arg0,

                         const SubstituteArg& arg1, const SubstituteArg& arg2,

                         const SubstituteArg& arg3, const SubstituteArg& arg4,

                         const SubstituteArg& arg5, const SubstituteArg& arg6,

                         const SubstituteArg& arg7, const SubstituteArg& arg8,

                         const SubstituteArg& arg9) {

    const SubstituteArg* const args_array[] = {&arg0, &arg1, &arg2, &arg3, &arg4,  &arg5,

                                               &arg6, &arg7, &arg8, &arg9, nullptr};

    // Determine total size needed.

    int size = SubstitutedSize(format, args_array);

    if (size == 0) return;

    // Build the string.

    int original_size = output->size();

    STLStringResizeUninitialized(output, original_size + size);

    char* target = string_as_array(output) + original_size;

    target = SubstituteToBuffer(format, args_array, target);

    DCHECK_EQ(target - output->data(), output->size());

}

SubstituteArg::SubstituteArg(const void* value) {

    COMPILE_ASSERT(sizeof(scratch_) >= sizeof(value) * 2 + 2, fix_sizeof_scratch_);

    if (value == nullptr) {

        text_ = "NULL";

        size_ = strlen(text_);

    } else {

        char* ptr = scratch_ + sizeof(scratch_);

        uintptr_t num = reinterpret_cast<uintptr_t>(value);

        static const char kHexDigits[] = "0123456789abcdef";

        do {

            *--ptr = kHexDigits[num & 0xf];

            num >>= 4;

        } while (num != 0);

        *--ptr = 'x';

        *--ptr = '0';

        text_ = ptr;

        size_ = scratch_ + sizeof(scratch_) - ptr;

    }

}

} // namespace strings