#include "src/ir/regexp/encoding/enc.h"
#include "src/util/range.h"

namespace re2c {

const uint32_t Enc::SURR_MIN = 0xD800;
const uint32_t Enc::SURR_MAX = 0xDFFF;
const uint32_t Enc::UNICODE_ERROR = 0xFFFD;

const uint32_t Enc::asc2ebc[256] =
    { /* Based on ISO 8859/1 and Code Page 37 */
        0x00, 0x01, 0x02, 0x03, 0x37, 0x2d, 0x2e, 0x2f, 0x16, 0x05, 0x25, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
        0x10, 0x11, 0x12, 0x13, 0x3c, 0x3d, 0x32, 0x26, 0x18, 0x19, 0x3f, 0x27, 0x1c, 0x1d, 0x1e, 0x1f,
        0x40, 0x5a, 0x7f, 0x7b, 0x5b, 0x6c, 0x50, 0x7d, 0x4d, 0x5d, 0x5c, 0x4e, 0x6b, 0x60, 0x4b, 0x61,
        0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, 0xf9, 0x7a, 0x5e, 0x4c, 0x7e, 0x6e, 0x6f,
        0x7c, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6,
        0xd7, 0xd8, 0xd9, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xba, 0xe0, 0xbb, 0xb0, 0x6d,
        0x79, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96,
        0x97, 0x98, 0x99, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, 0xa8, 0xa9, 0xc0, 0x4f, 0xd0, 0xa1, 0x07,
        0x20, 0x21, 0x22, 0x23, 0x24, 0x15, 0x06, 0x17, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x09, 0x0a, 0x1b,
        0x30, 0x31, 0x1a, 0x33, 0x34, 0x35, 0x36, 0x08, 0x38, 0x39, 0x3a, 0x3b, 0x04, 0x14, 0x3e, 0xff,
        0x41, 0xaa, 0x4a, 0xb1, 0x9f, 0xb2, 0x6a, 0xb5, 0xbd, 0xb4, 0x9a, 0x8a, 0x5f, 0xca, 0xaf, 0xbc,
        0x90, 0x8f, 0xea, 0xfa, 0xbe, 0xa0, 0xb6, 0xb3, 0x9d, 0xda, 0x9b, 0x8b, 0xb7, 0xb8, 0xb9, 0xab,
        0x64, 0x65, 0x62, 0x66, 0x63, 0x67, 0x9e, 0x68, 0x74, 0x71, 0x72, 0x73, 0x78, 0x75, 0x76, 0x77,
        0xac, 0x69, 0xed, 0xee, 0xeb, 0xef, 0xec, 0xbf, 0x80, 0xfd, 0xfe, 0xfb, 0xfc, 0xad, 0x8e, 0x59,
        0x44, 0x45, 0x42, 0x46, 0x43, 0x47, 0x9c, 0x48, 0x54, 0x51, 0x52, 0x53, 0x58, 0x55, 0x56, 0x57,
        0x8c, 0x49, 0xcd, 0xce, 0xcb, 0xcf, 0xcc, 0xe1, 0x70, 0xdd, 0xde, 0xdb, 0xdc, 0x8d, 0xae, 0xdf
    };

const uint32_t Enc::ebc2asc[256] =
    { /* Based on ISO 8859/1 and Code Page 37 */
        0x00, 0x01, 0x02, 0x03, 0x9c, 0x09, 0x86, 0x7f, 0x97, 0x8d, 0x8e, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
        0x10, 0x11, 0x12, 0x13, 0x9d, 0x85, 0x08, 0x87, 0x18, 0x19, 0x92, 0x8f, 0x1c, 0x1d, 0x1e, 0x1f,
        0x80, 0x81, 0x82, 0x83, 0x84, 0x0a, 0x17, 0x1b, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x05, 0x06, 0x07,
        0x90, 0x91, 0x16, 0x93, 0x94, 0x95, 0x96, 0x04, 0x98, 0x99, 0x9a, 0x9b, 0x14, 0x15, 0x9e, 0x1a,
        0x20, 0xa0, 0xe2, 0xe4, 0xe0, 0xe1, 0xe3, 0xe5, 0xe7, 0xf1, 0xa2, 0x2e, 0x3c, 0x28, 0x2b, 0x7c,
        0x26, 0xe9, 0xea, 0xeb, 0xe8, 0xed, 0xee, 0xef, 0xec, 0xdf, 0x21, 0x24, 0x2a, 0x29, 0x3b, 0xac,
        0x2d, 0x2f, 0xc2, 0xc4, 0xc0, 0xc1, 0xc3, 0xc5, 0xc7, 0xd1, 0xa6, 0x2c, 0x25, 0x5f, 0x3e, 0x3f,
        0xf8, 0xc9, 0xca, 0xcb, 0xc8, 0xcd, 0xce, 0xcf, 0xcc, 0x60, 0x3a, 0x23, 0x40, 0x27, 0x3d, 0x22,
        0xd8, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0xab, 0xbb, 0xf0, 0xfd, 0xde, 0xb1,
        0xb0, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, 0x70, 0x71, 0x72, 0xaa, 0xba, 0xe6, 0xb8, 0xc6, 0xa4,
        0xb5, 0x7e, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0xa1, 0xbf, 0xd0, 0xdd, 0xfe, 0xae,
        0x5e, 0xa3, 0xa5, 0xb7, 0xa9, 0xa7, 0xb6, 0xbc, 0xbd, 0xbe, 0x5b, 0x5d, 0xaf, 0xa8, 0xb4, 0xd7,
        0x7b, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0xad, 0xf4, 0xf6, 0xf2, 0xf3, 0xf5,
        0x7d, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50, 0x51, 0x52, 0xb9, 0xfb, 0xfc, 0xf9, 0xfa, 0xff,
        0x5c, 0xf7, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0xb2, 0xd4, 0xd6, 0xd2, 0xd3, 0xd5,
        0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0xb3, 0xdb, 0xdc, 0xd9, 0xda, 0x9f
    };

/*
 * Returns code point representation for current
 * encoding with regard to current policy.
 *
 * Since code point is exacly specified by user,
 * it is assumed that user considers it to be valid.
 * We must check it.
 *
 * Returns false if this code point exceeds maximum
 * or is forbidden by current policy, otherwise
 * returns true. Overwrites code point.
 */
bool Enc::encode(uint32_t & c) const
{
	if (c >= nCodePoints ())
	{
		return false;
	}

	switch (type_)
	{
		case ASCII:
			return true;
		case EBCDIC:
			c = asc2ebc[c];
			return true;
		case UCS2:
		case UTF16:
		case UTF32:
		case UTF8:
			if (c < SURR_MIN || c > SURR_MAX)
				return true;
			else
			{
				switch (policy_)
				{
					case POLICY_FAIL:
						return false;
					case POLICY_SUBSTITUTE:
						c = UNICODE_ERROR;
						return true;
					case POLICY_IGNORE:
						return true;
				}
			}
	}
	return false; // to silence gcc warning
}

/*
 * Returns original representation of code point.
 * Assumes code point is valid (hence 'unsafe').
 */
uint32_t Enc::decodeUnsafe(uint32_t c) const
{
	switch (type_)
	{
		case EBCDIC:
			c = ebc2asc[c & 0xFF];
			break;
		case ASCII:
		case UCS2:
		case UTF16:
		case UTF32:
		case UTF8:
			break;
	}
	return c;
}

/*
 * Returns [l - h] range representation for current
 * encoding with regard to current policy.
 *
 * Since range borders are exacly specified by user,
 * it is assumed that user considers that all code
 * points from this range are valid. re2c must check it.
 *
 * Returns NULL if range contains code points that
 * exceed maximum or are forbidden by current policy,
 * otherwise returns pointer to newly constructed range.
 */
Range * Enc::encodeRange(uint32_t l, uint32_t h) const
{
	if (l >= nCodePoints () || h >= nCodePoints ())
	{
		return NULL;
	}

	Range * r = NULL;
	switch (type_)
	{
		case ASCII:
			r = Range::ran (l, h + 1);
			break;
		case EBCDIC:
		{
			const uint32_t el = asc2ebc[l];
			r = Range::sym (el);
			for (uint32_t c = l + 1; c <= h; ++c)
			{
				const uint32_t ec = asc2ebc[c];
				r = Range::add (r, Range::sym (ec));
			}
			break;
		}
		case UCS2:
		case UTF16:
		case UTF32:
		case UTF8:
			r = Range::ran (l, h + 1);
			if (l <= SURR_MAX && h >= SURR_MIN)
			{
				switch (policy_)
				{
					case POLICY_FAIL:
						r = NULL;
						break;
					case POLICY_SUBSTITUTE:
					{
						Range * surrs = Range::ran (SURR_MIN, SURR_MAX + 1);
						Range * error = Range::sym (UNICODE_ERROR);
						r = Range::sub (r, surrs);
						r = Range::add (r, error);
						break;
					}
					case POLICY_IGNORE:
						break;
				}
			}
			break;
	}
	return r;
}

/*
 * Returns full range representation for current encoding
 * with regard to current policy.
 *
 * Since range is defined declaratively, re2c does
 * all the necessary corrections 'for free'.
 *
 * Always succeeds, returns pointer to newly constructed
 * range.
 */
Range * Enc::fullRange() const
{
	Range * r = Range::ran (0, nCodePoints());
	if (policy_ != POLICY_IGNORE)
	{
		Range * surrs = Range::ran (SURR_MIN, SURR_MAX + 1);
		r = Range::sub (r, surrs);
	}
	return r;
}

} // namespace re2c
