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/*
* Copyright (c) 2020-2022, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/GenericLexer.h>
#include <AK/OwnPtr.h>
#include <AK/Stream.h>
#include <AK/String.h>
#include <AK/StringView.h>
#include <AK/Types.h>
#include <AK/Vector.h>
namespace Writer {
enum class WriterBehavior : u32 {
None = 0,
WriteHeaders = 1,
AllowNewlinesInFields = WriteHeaders << 1,
QuoteOnlyInFieldStart = WriteHeaders << 2,
QuoteAll = WriteHeaders << 3,
};
inline WriterBehavior operator&(WriterBehavior left, WriterBehavior right)
{
return static_cast<WriterBehavior>(static_cast<u32>(left) & static_cast<u32>(right));
}
inline WriterBehavior operator|(WriterBehavior left, WriterBehavior right)
{
return static_cast<WriterBehavior>(static_cast<u32>(left) | static_cast<u32>(right));
}
struct WriterTraits {
String separator;
String quote { "\"" };
enum QuoteEscape {
Repeat,
Backslash,
} quote_escape { Repeat };
};
#define ENUMERATE_WRITE_ERRORS() \
E(None, "No errors") \
E(NonConformingColumnCount, "Header count does not match given column count") \
E(InternalError, "Internal error")
enum class WriteError {
#define E(name, _) name,
ENUMERATE_WRITE_ERRORS()
#undef E
};
constexpr WriterBehavior default_behaviors()
{
return WriterBehavior::None;
}
template<typename ContainerType, typename HeaderType = Vector<StringView>>
class XSV {
public:
XSV(OutputStream& output, ContainerType const& data, WriterTraits const& traits, HeaderType const& headers = {}, WriterBehavior behaviors = default_behaviors())
: m_data(data)
, m_traits(traits)
, m_behaviors(behaviors)
, m_names(headers)
, m_output(output)
{
if (!headers.is_empty())
m_behaviors = m_behaviors | WriterBehavior::WriteHeaders;
generate();
}
virtual ~XSV() = default;
bool has_error() const { return m_error != WriteError::None; }
WriteError error() const { return m_error; }
String error_string() const
{
switch (m_error) {
#define E(x, y) \
case WriteError::x: \
return y;
ENUMERATE_WRITE_ERRORS();
#undef E
}
VERIFY_NOT_REACHED();
}
private:
void set_error(WriteError error)
{
if (m_error == WriteError::None)
m_error = error;
}
void generate()
{
auto with_headers = (m_behaviors & WriterBehavior::WriteHeaders) != WriterBehavior::None;
if (with_headers) {
write_row(m_names);
if (m_output.write({ "\n", 1 }) != 1)
set_error(WriteError::InternalError);
}
for (auto&& row : m_data) {
if (with_headers) {
if (row.size() != m_names.size())
set_error(WriteError::NonConformingColumnCount);
}
write_row(row);
if (m_output.write({ "\n", 1 }) != 1)
set_error(WriteError::InternalError);
}
}
template<typename T>
void write_row(T&& row)
{
bool first = true;
for (auto&& entry : row) {
if (!first) {
if (m_output.write(m_traits.separator.bytes()) != m_traits.separator.length())
set_error(WriteError::InternalError);
}
first = false;
write_entry(entry);
}
}
template<typename T>
void write_entry(T&& entry)
{
auto string = String::formatted("{}", FormatIfSupported(entry));
auto safe_to_write_normally = (m_behaviors & WriterBehavior::QuoteAll) == WriterBehavior::None
&& !string.contains("\n")
&& !string.contains(m_traits.separator);
if (safe_to_write_normally) {
if ((m_behaviors & WriterBehavior::QuoteOnlyInFieldStart) == WriterBehavior::None)
safe_to_write_normally = !string.contains(m_traits.quote);
else
safe_to_write_normally = !string.starts_with(m_traits.quote);
}
if (safe_to_write_normally) {
if (m_output.write(string.bytes()) != string.length())
set_error(WriteError::InternalError);
return;
}
if (m_output.write(m_traits.quote.bytes()) != m_traits.quote.length())
set_error(WriteError::InternalError);
GenericLexer lexer(string);
while (!lexer.is_eof()) {
if (lexer.consume_specific(m_traits.quote)) {
switch (m_traits.quote_escape) {
case WriterTraits::Repeat:
if (m_output.write(m_traits.quote.bytes()) != m_traits.quote.length())
set_error(WriteError::InternalError);
if (m_output.write(m_traits.quote.bytes()) != m_traits.quote.length())
set_error(WriteError::InternalError);
break;
case WriterTraits::Backslash:
if (m_output.write({ "\\", 1 }) != 1)
set_error(WriteError::InternalError);
if (m_output.write(m_traits.quote.bytes()) != m_traits.quote.length())
set_error(WriteError::InternalError);
break;
}
continue;
}
auto ch = lexer.consume();
if (m_output.write({ &ch, 1 }) != 1)
set_error(WriteError::InternalError);
}
if (m_output.write(m_traits.quote.bytes()) != m_traits.quote.length())
set_error(WriteError::InternalError);
}
ContainerType const& m_data;
WriterTraits const& m_traits;
WriterBehavior m_behaviors;
HeaderType const& m_names;
WriteError m_error { WriteError::None };
OutputStream& m_output;
};
}
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