#include "common.h"
#include "rds.h"
#include "modulator.h"
#include "lib.h"
#include <time.h>

void saveToFile(const char *filename, RDSEncoder *emp) {
    FILE *file = fopen(filename, "wb");
    if (file == NULL) {
        perror("Error opening file");
        return;
    }
    fwrite(emp, sizeof(RDSEncoder), 1, file);
    fclose(file);
}

void loadFromFile(const char *filename, RDSEncoder *emp) {
    FILE *file = fopen(filename, "rb");
    if (file == NULL) {
        perror("Error opening file");
        return;
    }
    fread(emp, sizeof(RDSEncoder), 1, file);
    fclose(file);
}

int fileExists(const char *filename) {
    FILE *file = fopen(filename, "rb");
    if (file) {
        fclose(file);
        return 1;
    }
    return 0;
}

static void register_oda(RDSEncoder* enc, uint8_t group, uint16_t aid, uint16_t scb) {
	if (enc->oda_state[enc->program].count >= MAX_ODAS) return;

	enc->odas[enc->program][oda_state.count].group = group;
	enc->odas[enc->program][oda_state.count].aid = aid;
	enc->odas[enc->program][oda_state.count].scb = scb;
	enc->oda_state[enc->program].count++;
}

static uint16_t get_next_af(RDSEncoder* enc) {
	static uint8_t af_state;
	uint16_t out;

	if (enc->data[enc->program].af.num_afs) {
		if (af_state == 0) {
			out = (AF_CODE_NUM_AFS_BASE + enc->data[enc->program].af.num_afs) << 8;
			out |= enc->data[enc->program].af.afs[0];
			af_state += 1;
		} else {
			out = enc->data[enc->program].af.afs[af_state] << 8;
			if (enc->data[enc->program].af.afs[af_state + 1])
				out |= enc->data[enc->program].af.afs[af_state + 1];
			else
				out |= AF_CODE_FILLER;
			af_state += 2;
		}
		if (af_state >= enc->data[enc->program].af.num_entries) af_state = 0;
	} else {
		out = AF_CODE_NO_AF << 8 | AF_CODE_FILLER;
	}

	return out;
}
// #endregion

// #region Group encoding
static void get_rds_ps_group(RDSEncoder* enc, uint16_t *blocks) {
	static unsigned char ps_text[PS_LENGTH];
	static unsigned char tps_text[PS_LENGTH];
	static uint8_t ps_csegment;

	if (ps_csegment == 0 && enc->state[enc->program][enc->program].ps_update) {
		memcpy(ps_text, enc->data[enc->program].ps, PS_LENGTH);
		enc->state[enc->program][enc->program].ps_update = 0;
	}
	if(ps_csegment == 0 && enc->state[enc->program][enc->program].tps_update) {
		memcpy(tps_text, enc->data[enc->program].tps, PS_LENGTH);
		enc->state[enc->program][enc->program].tps_update = 0;
	}

	blocks[1] |= enc->data[enc->program].ta << 4;
	blocks[1] |= enc->data[enc->program].ms << 3;
	blocks[1] |= ((enc->data[enc->program].di >> (3 - ps_csegment)) & INT8_0) << 2;
	blocks[1] |= ps_csegment;
	blocks[2] = get_next_af(enc);
	if(enc->data[enc->program].ta && tps_text[0] != '\0') {
		blocks[3] = tps_text[ps_csegment * 2] << 8 | tps_text[ps_csegment * 2 + 1];
	} else {
		/* TODO: Add DPS */
		blocks[3] =  ps_text[ps_csegment * 2] << 8 |  ps_text[ps_csegment * 2 + 1];
	}
	ps_csegment++;
	if (ps_csegment >= 4) ps_csegment = 0;
}

static uint8_t get_rds_rt_group(RDSEncoder* enc, uint16_t *blocks) {
	static unsigned char rt_text[RT_LENGTH];
	static uint8_t rt_state;

	if (enc->state[enc->program].rt_update) {
		memcpy(rt_text, enc->data[enc->program].rt1, RT_LENGTH);
		enc->state[enc->program].rt_ab ^= 1;
		enc->state[enc->program].rt_update = 0;
		rt_state = 0;
	}

	blocks[1] |= 2 << 12;
	blocks[1] |= enc->state[enc->program].rt_ab << 4;
	blocks[1] |= rt_state;
	blocks[2] =  rt_text[rt_state * 4    ] << 8;
	blocks[2] |= rt_text[rt_state * 4 + 1];
	blocks[3] =  rt_text[rt_state * 4 + 2] << 8;
	blocks[3] |= rt_text[rt_state * 4 + 3];

	rt_state++;
	if (rt_state >= enc->state[enc->program].rt_segments) rt_state = 0;
	return 1;
}

static void get_rds_oda_group(RDSEncoder* enc, uint16_t *blocks) {
	RDSODA this_oda = enc->odas[enc->oda_state[enc->program].current];

	blocks[1] |= 3 << 12;

	blocks[1] |= GET_GROUP_TYPE(this_oda.group) << 1;
	blocks[1] |= GET_GROUP_VER(this_oda.group);
	blocks[2] = this_oda.scb;
	blocks[3] = this_oda.aid;

	enc->oda_state[enc->program].current++;
	if (enc->oda_state[enc->program].current >= enc->oda_state[enc->program].count) enc->oda_state[enc->program].current = 0;
}

static uint8_t get_rds_ct_group(RDSEncoder* enc, uint16_t *blocks) {
	static uint8_t latest_minutes;
	struct tm *utc, *local_time;
	time_t now;
	uint8_t l;
	uint32_t mjd;
	int16_t offset;

	now = time(NULL);
	utc = gmtime(&now);

	if (utc->tm_min != latest_minutes) {
		latest_minutes = utc->tm_min;

		l = utc->tm_mon <= 1 ? 1 : 0;
		mjd = 14956 + utc->tm_mday +
			(uint32_t)((utc->tm_year - l) * 365.25f) +
			(uint32_t)((utc->tm_mon + (1+1) + l * 12) * 30.6001f);

		blocks[1] |= 4 << 12 | (mjd >> 15);
		blocks[2] = (mjd << 1) | (utc->tm_hour >> 4);
		blocks[3] = (utc->tm_hour & INT16_L4) << 12 | utc->tm_min << 6;

		local_time = localtime(&now);

		offset = local_time->__tm_gmtoff / (30 * 60);
		if (offset < 0) blocks[3] |= 1 << 5;
		blocks[3] |= abs(offset);

		return 1;
	}

	return 0;
}

static void get_rds_ptyn_group(RDSEncoder* enc, uint16_t *blocks) {
	static unsigned char ptyn_text[PTYN_LENGTH];
	static uint8_t ptyn_state;

	if (ptyn_state == 0 && enc->state[enc->program].ptyn_update) {
		memcpy(ptyn_text, enc->data[enc->program].ptyn, PTYN_LENGTH);
		enc->state[enc->program].ptyn_ab ^= 1;
		enc->state[enc->program].ptyn_update = 0;
	}

	blocks[1] |= 10 << 12 | ptyn_state;
	blocks[1] |= enc->state[enc->program].ptyn_ab << 4;
	blocks[2] =  ptyn_text[ptyn_state * 4 + 0] << 8;
	blocks[2] |= ptyn_text[ptyn_state * 4 + 1];
	blocks[3] =  ptyn_text[ptyn_state * 4 + 2] << 8;
	blocks[3] |= ptyn_text[ptyn_state * 4 + 3];

	ptyn_state++;
	if (ptyn_state == 2) ptyn_state = 0;
}

static void get_rds_lps_group(RDSEncoder* enc, uint16_t *blocks) {
	static unsigned char lps_text[LPS_LENGTH];
	static uint8_t lps_state;

	if (lps_state == 0 && enc->state[enc->program].lps_update) {
		memcpy(lps_text, enc->data[enc->program].lps, LPS_LENGTH);
		enc->state[enc->program].lps_update = 0;
	}

	blocks[1] |= 15 << 12 | lps_state;
	blocks[2] =  lps_text[lps_state * 4    ] << 8;
	blocks[2] |= lps_text[lps_state * 4 + 1];
	blocks[3] =  lps_text[lps_state * 4 + 2] << 8;
	blocks[3] |= lps_text[lps_state * 4 + 3];

	lps_state++;
	if (lps_state == enc->state[enc->program].lps_segments) lps_state = 0;
}

static void get_rds_ecc_group(RDSEncoder* enc, uint16_t *blocks) {
	blocks[1] |= 1 << 12;
	blocks[2] = enc->data[enc->program].ecc;

	if(enc->data[enc->program].pin[0]) {
		blocks[3] = enc->data[enc->program].pin[1] << 11; // day
		blocks[3] |= enc->data[enc->program].pin[2] << 6; // hour
		blocks[3] |= enc->data[enc->program].pin[3]; // minute
	}
}

static void get_rds_lic_group(RDSEncoder* enc, uint16_t *blocks) {
	blocks[1] |= 1 << 12;
	blocks[2] = 0x3000; // 0b0011000000000000
	blocks[2] |= enc->data[enc->program].lic;

	if(enc->data[enc->program].pin[0]) {
		blocks[3] = enc->data[enc->program].pin[1] << 11; // day
		blocks[3] |= enc->data[enc->program].pin[2] << 6; // hour
		blocks[3] |= enc->data[enc->program].pin[3]; // minute
	}
}
static void get_rds_rtplus_group(RDSEncoder* enc, uint16_t *blocks) {
	blocks[1] |= GET_GROUP_TYPE(enc->rtpData[enc->program].group) << 12;
	blocks[1] |= GET_GROUP_VER(enc->rtpData[enc->program].group) << 11;
	blocks[1] |= enc->rtpData[enc->program].toggle << 4 | enc->rtpData[enc->program].running << 3;
	blocks[1] |= (enc->rtpData[enc->program].type[0] & INT8_U5) >> 3;

	blocks[2] =  (enc->rtpData[enc->program].type[0] & INT8_L3) << 13;
	blocks[2] |= (enc->rtpData[enc->program].start[0] & INT8_L6) << 7;
	blocks[2] |= (enc->rtpData[enc->program].len[0] & INT8_L6) << 1;
	blocks[2] |= (enc->rtpData[enc->program].type[1] & INT8_U3) >> 5;

	blocks[3] =  (enc->rtpData[enc->program].type[1] & INT8_L5) << 11;
	blocks[3] |= (enc->rtpData[enc->program].start[1] & INT8_L6) << 5;
	blocks[3] |= enc->rtpData[enc->program].len[1] & INT8_L5;
}
// #endregion

static uint8_t get_rds_custom_groups(RDSEncoder* enc, uint16_t *blocks) {
	if(enc->state[enc->program].custom_group[0] == 1) {
		enc->state[enc->program].custom_group[0] = 0;
		blocks[0] = enc->data[enc->program].pi;
		blocks[1] = enc->state[enc->program].custom_group[1];
		blocks[2] = enc->state[enc->program].custom_group[2];
		blocks[3] = enc->state[enc->program].custom_group[3];
		return 1;
	}
	return 0;
}

static void get_rds_group(RDSEncoder* enc, uint16_t *blocks) {
	blocks[0] = enc->data[enc->program].pi;
	blocks[1] = enc->data[enc->program].tp << 10;
	blocks[1] |= enc->data[enc->program].pty << 5;
	blocks[2] = 0;
	blocks[3] = 0;

	if (enc->data[enc->program].ct && get_rds_ct_group(enc, blocks)) {
		goto group_coded;
	}

	if(get_rds_custom_groups(enc, blocks)) {
		goto group_coded;
	}

	uint8_t good_group = 0;
	uint8_t cant_find_group = 0;
	char grp;

	while(good_group == 0) {
		uint8_t grp_sqc_idx = enc->state[enc->program].grp_seq_idx[0]++;
		if(enc->data[enc->program].grp_sqc[grp_sqc_idx] == '\0') {
			enc->state[enc->program].grp_seq_idx[0] = 0;
			grp_sqc_idx = 0;
		}
		grp = enc->data[enc->program].grp_sqc[grp_sqc_idx];

		if(grp == '0') good_group = 1;
		if(grp == '1' && enc->data[enc->program].ecclic_enabled) good_group = 1;
		if(grp == '2' && enc->data[enc->program].rt1_enabled) good_group = 1;
		if(grp == 'A' && enc->state[enc->program].ptyn_enabled) good_group = 1;
		if(grp == 'X' && enc->data[enc->program].udg1_len != 0) good_group = 1;
		if(grp == 'Y' && enc->data[enc->program].udg2_len != 0) good_group = 1;
		if(grp == 'R' && enc->rtpData[enc->program].enabled) good_group = 1;
		if(grp == '3' && enc->oda_state[enc->program].count != 0) good_group = 1;
		if(grp == 'F' && enc->data[enc->program].lps[0] != '\0') good_group = 1;

		if(!good_group) cant_find_group++;
		else cant_find_group = 0;
		if(!good_group && cant_find_group == 23) {
			cant_find_group = 0;
			return;
			break;
		}
	}

	uint8_t idx;
	switch (grp)
	{
		default:
		case '0':
			if(enc->state[enc->program].grp_seq_idx[1] != 3) enc->state[enc->program].grp_seq_idx[0]--;
			else enc->state[enc->program].grp_seq_idx[1] = 0;
			enc->state[enc->program].grp_seq_idx[1]++;
			get_rds_ps_group(enc, blocks);
			goto group_coded;
		case '1':
			if(enc->data[enc->program].ecc && enc->data[enc->program].lic) {
				if(enc->state[enc->program].ecc_or_lic == 0) {
					get_rds_ecc_group(enc, blocks);
				} else {
					get_rds_lic_group(enc, blocks);
				}
				enc->state[enc->program].ecc_or_lic ^= 1;
			} else if(enc->data[enc->program].lic) {
				get_rds_lic_group(enc, blocks);
			} else {
				get_rds_ecc_group(enc, blocks);
			}
			goto group_coded;
		case '2':
			get_rds_rt_group(enc, blocks);
			goto group_coded;
		case 'A':
			get_rds_ptyn_group(enc, blocks);
			goto group_coded;
		// TODO: Add EON
		case 'X':
			idx = enc->state[enc->program].udg_idxs[0];
			for(int i = 0; i < 3; i++) blocks[i+1] = enc->data[enc->program].udg1[idx][i];
			enc->state[enc->program].udg_idxs[0]++;
			if(enc->state[enc->program].udg_idxs[0] == enc->data[enc->program].udg1_len) enc->state[enc->program].udg_idxs[0] = 0;
			goto group_coded;
		case 'Y':
			idx = enc->state[enc->program].udg_idxs[1];
			for(int i = 0; i < 3; i++) blocks[i+1] = enc->data[enc->program].udg2[idx][i];
			enc->state[enc->program].udg_idxs[1]++;
			if(enc->state[enc->program].udg_idxs[1] == enc->data[enc->program].udg2_len) enc->state[enc->program].udg_idxs[1] = 0;
			goto group_coded;
		case 'R':
			if(enc->state[enc->program].rtp_oda == 0) {
				get_rds_rtplus_group(enc, blocks);
			} else {
				get_rds_oda_group(enc, blocks);
			}
			enc->state[enc->program].rtp_oda ^= 1;
			goto group_coded;
		// TODO: add uecp
		case '3':
			get_rds_oda_group(enc, blocks);
			goto group_coded;
		case 'F':
			get_rds_lps_group(enc, blocks);
			goto group_coded;
	}


group_coded:
	if (IS_TYPE_B(blocks)) {
		blocks[2] = enc->data[enc->program].pi;
	}
}

void get_rds_bits(RDSEncoder* enc, uint8_t *bits) {
	static uint16_t out_blocks[GROUP_LENGTH];
	get_rds_group(enc, out_blocks);
	add_checkwords(enc, out_blocks, bits);
}

static void init_rtplus(RDSEncoder* enc, uint8_t group) {
	register_oda(enc, group, ODA_AID_RTPLUS, 0);
	enc->rtpData[enc->program].group = group;
	enc->rtpData[enc->program].enabled = 0;
}

void init_rds_encoder(RDSEncoder* enc) {
	memset(&enc->data[enc->program].af, 0, sizeof(RDSAFs));
	enc->data[enc->program].ct = 1;
	enc->data[enc->program].di = 1;
	enc->data[enc->program].ecclic_enabled = 1;
	enc->data[enc->program].grp_sqc = (unsigned char*)"002222\0";
	enc->data[enc->program].ms = 1;
	enc->data[enc->program].pi = 0xFFFF;
	enc->data[enc->program].ps = (unsigned char*)"* RDS *";
	enc->data[enc->program].rt1_enabled = 1;

	enc->state[enc->program].rt_ab = 1;
	enc->state[enc->program].ptyn_ab = 1;

	init_rtplus(GROUP_11A);

	if(fileExists("~/.rdsEncoder")) {
		loadFromFile("~/.rdsEncoder", enc);
	} else {
		saveToFile("~/.rdsEncoder");
	}

	init_rds_objects();
}

void set_rds_rt1(RDSEncoder* enc, unsigned char *rt1) {
	uint8_t i = 0, len = 0;

	enc->state[enc->program].rt_update = 1;

	memset(enc->data[enc->program].rt1, ' ', RT_LENGTH);
	while (*rt1 != 0 && len < RT_LENGTH) enc->data[enc->program].rt1[len++] = *rt1++;

	if (len < RT_LENGTH && enc->data[enc->program].shortrt) {
		enc->state[enc->program].rt_segments = 0;

		enc->data[enc->program].rt1[len++] = '\r';

		while (i < len) {
			i += 4;
			enc->state[enc->program].rt_segments++;
		}
	} else {
		enc->state[enc->program].rt_segments = 16;
	}
}

void set_rds_ps(RDSEncoder* enc, unsigned char *ps) {
	uint8_t len = 0;

	enc->state[enc->program].ps_update = 1;
	memset(enc->data[enc->program].ps, ' ', PS_LENGTH);
	while (*ps != 0 && len < PS_LENGTH) enc->data[enc->program].ps[len++] = *ps++;
}

void set_rds_tps(RDSEncoder* enc, unsigned char *tps) {
	uint8_t len = 0;

	enc->state[enc->program].tps_update = 1;
	if(tps[0] == '\0') {
		memset(enc->data[enc->program].tps, 0, PS_LENGTH);
		return;
	}

	memset(enc->data[enc->program].tps, ' ', PS_LENGTH);
	while (*tps != 0 && len < PS_LENGTH) enc->data[enc->program].tps[len++] = *tps++;
}

void set_rds_lps(RDSEncoder* enc, unsigned char *lps) {
	uint8_t i = 0, len = 0;

	enc->state[enc->program].lps_update = 1;
	if(lps[0] == '\0') {
		memset(enc->data[enc->program].lps, 0, LPS_LENGTH);
		return;
	}
	memset(enc->data[enc->program].lps, '\r', LPS_LENGTH);
	while (*lps != 0 && len < LPS_LENGTH) enc->data[enc->program].lps[len++] = *lps++;

	if (len < LPS_LENGTH) {
		enc->state[enc->program].lps_segments = 0;

		len++;

		while (i < len) {
			i += 4;
			enc->state[enc->program].lps_segments++;
		}
	} else {
		enc->state[enc->program].lps_segments = 8;
	}
}

void set_rds_rtplus_flags(RDSEncoder* enc, uint8_t flags) {
	enc->rtpData[enc->program].enabled = (flags==2);
	enc->rtpData[enc->program].running	= flags & INT8_0;
}

void set_rds_rtplus_tags(RDSEncoder* enc, uint8_t *tags) {
	enc->rtpData[enc->program].type[0]	= tags[0] & INT8_L6;
	enc->rtpData[enc->program].start[0]	= tags[1] & INT8_L6;
	enc->rtpData[enc->program].len[0]	= tags[2] & INT8_L6;
	enc->rtpData[enc->program].type[1]	= tags[3] & INT8_L6;
	enc->rtpData[enc->program].start[1]	= tags[4] & INT8_L6;
	enc->rtpData[enc->program].len[1]	= tags[5] & INT8_L5;

	enc->rtpData[enc->program].toggle ^= 1;
	enc->rtpData[enc->program].running = 1;
	enc->rtpData[enc->program].enabled = 1;
}

void set_rds_ptyn(RDSEncoder* enc, unsigned char *ptyn) {
	uint8_t len = 0;

	enc->state[enc->program].ptyn_update = 1;

	if(ptyn[0] == '\0') {
		memset(enc->data[enc->program].ptyn, 0, PTYN_LENGTH);
		return;
	}

	memset(enc->data[enc->program].ptyn, ' ', PTYN_LENGTH);
	while (*ptyn != 0 && len < PTYN_LENGTH) enc->data[enc->program].ptyn[len++] = *ptyn++;
}