#include "meta.h"
#include "../coding/coding.h"
#include "../layout/layout.h"


#define TXT_LINE_MAX 0x2000
#ifdef VGMSTREAM_MIXING
#define TXTP_MIXING_MAX 64
#endif

typedef struct {
    char filename[TXT_LINE_MAX];
    int subsong;
    uint32_t channel_mask;
    int channel_mappings_on;
    int channel_mappings[32];

#if VGMSTREAM_MIXING
    int mixing_count;
    mix_config_data mixing[TXTP_MIXING_MAX];
#endif

    double config_loop_count;
    double config_fade_time;
    double config_fade_delay;
    int config_ignore_loop;
    int config_force_loop;
    int config_ignore_fade;

    int sample_rate;

} txtp_entry;

typedef struct {
    txtp_entry *entry;
    size_t entry_count;
    size_t entry_max;

    uint32_t loop_start_segment;
    uint32_t loop_end_segment;

    txtp_entry default_entry;
    int default_entry_set;

    size_t is_layered;
    int is_loop_keep;
} txtp_header;

static txtp_header* parse_txtp(STREAMFILE* streamFile);
static void clean_txtp(txtp_header* txtp);
static void apply_config(VGMSTREAM *vgmstream, txtp_entry *current);


/* TXTP - an artificial playlist-like format to play files with segments/layers/config */
VGMSTREAM * init_vgmstream_txtp(STREAMFILE *streamFile) {
    VGMSTREAM * vgmstream = NULL;
    txtp_header* txtp = NULL;
    segmented_layout_data *data_s = NULL;
    layered_layout_data * data_l = NULL;
    int i;


    /* checks */
    if (!check_extensions(streamFile, "txtp"))
        goto fail;

    /* read .txtp text file to get segments */
    txtp = parse_txtp(streamFile);
    if (!txtp) goto fail;


    if (txtp->entry_count == 0)
        goto fail;


    if (txtp->entry_count == 1 && !txtp->loop_start_segment) {
        /* single file */
        STREAMFILE* temp_streamFile = open_streamfile_by_filename(streamFile, txtp->entry[0].filename);
        if (!temp_streamFile) goto fail;
        temp_streamFile->stream_index = txtp->entry[0].subsong;

        vgmstream = init_vgmstream_from_STREAMFILE(temp_streamFile);
        close_streamfile(temp_streamFile);
        if (!vgmstream) goto fail;

        apply_config(vgmstream, &txtp->entry[0]);
    }
    else if (txtp->is_layered) {
        /* layered multi file */
        int channel_count = 0, loop_flag;

        /* init layout */
        data_l = init_layout_layered(txtp->entry_count);
        if (!data_l) goto fail;

        /* open each segment subfile */
        for (i = 0; i < txtp->entry_count; i++) {
            STREAMFILE* temp_streamFile = open_streamfile_by_filename(streamFile, txtp->entry[i].filename);
            if (!temp_streamFile) goto fail;
            temp_streamFile->stream_index = txtp->entry[i].subsong;

            data_l->layers[i] = init_vgmstream_from_STREAMFILE(temp_streamFile);
            close_streamfile(temp_streamFile);
            if (!data_l->layers[i]) goto fail;

            apply_config(data_l->layers[i], &txtp->entry[i]);

            /* get actual channel count after config */
            channel_count += data_l->layers[i]->channels;
        }

        /* setup layered VGMSTREAMs */
        if (!setup_layout_layered(data_l))
            goto fail;

        loop_flag = data_l->layers[0]->loop_flag;

        /* build the VGMSTREAM */
        vgmstream = allocate_vgmstream(channel_count,loop_flag);
        if (!vgmstream) goto fail;

        vgmstream->sample_rate = data_l->layers[0]->sample_rate;
        vgmstream->num_samples = data_l->layers[0]->num_samples;
        vgmstream->loop_start_sample = data_l->layers[0]->loop_start_sample;
        vgmstream->loop_end_sample = data_l->layers[0]->loop_end_sample;

        vgmstream->meta_type = meta_TXTP;
        vgmstream->coding_type = data_l->layers[0]->coding_type;
        vgmstream->layout_type = layout_layered;

        vgmstream->layout_data = data_l;
    }
    else {
        /* segmented multi file */
        int num_samples, loop_start_sample = 0, loop_end_sample = 0;
        int loop_flag, channel_count;

        /* init layout */
        data_s = init_layout_segmented(txtp->entry_count);
        if (!data_s) goto fail;

        /* open each segment subfile */
        for (i = 0; i < txtp->entry_count; i++) {
            STREAMFILE* temp_streamFile = open_streamfile_by_filename(streamFile, txtp->entry[i].filename);
            if (!temp_streamFile) goto fail;
            temp_streamFile->stream_index = txtp->entry[i].subsong;

            data_s->segments[i] = init_vgmstream_from_STREAMFILE(temp_streamFile);
            close_streamfile(temp_streamFile);
            if (!data_s->segments[i]) goto fail;

            apply_config(data_s->segments[i], &txtp->entry[i]);
        }

        /* setup segmented VGMSTREAMs */
        if (!setup_layout_segmented(data_s))
            goto fail;

        /* get looping and samples */
        if (txtp->loop_start_segment && !txtp->loop_end_segment)
            txtp->loop_end_segment = txtp->entry_count;
        loop_flag = (txtp->loop_start_segment > 0 && txtp->loop_start_segment <= txtp->entry_count);

        num_samples = 0;
        for (i = 0; i < data_s->segment_count; i++) {

            if (loop_flag && txtp->loop_start_segment == i+1) {
                if (txtp->is_loop_keep /*&& data_s->segments[i]->loop_start_sample*/)
                    loop_start_sample = num_samples + data_s->segments[i]->loop_start_sample;
                else
                    loop_start_sample = num_samples;
            }

            num_samples += data_s->segments[i]->num_samples;

            if (loop_flag && txtp->loop_end_segment == i+1) {
                if (txtp->is_loop_keep && data_s->segments[i]->loop_end_sample)
                    loop_end_sample = num_samples - data_s->segments[i]->num_samples + data_s->segments[i]->loop_end_sample;
                else
                    loop_end_sample = num_samples;
            }
        }

        channel_count = data_s->segments[0]->channels;

        /* build the VGMSTREAM */
        vgmstream = allocate_vgmstream(channel_count,loop_flag);
        if (!vgmstream) goto fail;

        vgmstream->sample_rate = data_s->segments[0]->sample_rate;
        vgmstream->num_samples = num_samples;
        vgmstream->loop_start_sample = loop_start_sample;
        vgmstream->loop_end_sample = loop_end_sample;

        vgmstream->meta_type = meta_TXTP;
        vgmstream->coding_type = data_s->segments[0]->coding_type;
        vgmstream->layout_type = layout_segmented;
        vgmstream->layout_data = data_s;
    }


    /* apply default config to the resulting file */
    if (txtp->default_entry_set) {
        apply_config(vgmstream, &txtp->default_entry);
    }


    clean_txtp(txtp);
    return vgmstream;

fail:
    clean_txtp(txtp);
    close_vgmstream(vgmstream);
    free_layout_segmented(data_s);
    free_layout_layered(data_l);
    return NULL;
}

static void apply_config(VGMSTREAM *vgmstream, txtp_entry *current) {
    vgmstream->channel_mask = current->channel_mask;

    vgmstream->channel_mappings_on = current->channel_mappings_on;
    if (vgmstream->channel_mappings_on) {
        int ch;
        for (ch = 0; ch < 32; ch++) {
            vgmstream->channel_mappings[ch] = current->channel_mappings[ch];
        }
    }

#ifdef VGMSTREAM_MIXING
    if (current->mixing_count > 0) {
        int i, ch_max_cur;
        if (vgmstream->mixing_count + current->mixing_count > vgmstream->mixing_size) {
            VGM_LOG("TXTP: ignored mixing\n");
            return;
        }

        ch_max_cur = vgmstream->channels;

        for (i = 0; i < current->mixing_count; i++) {
            mix_config_data mix = current->mixing[i];

            vgmstream->mixing[vgmstream->mixing_count] = mix;
            vgmstream->mixing_count++;

            /* some mixes change output channels */
            switch(vgmstream->mixing[i].command) {
                case MIX_DOWNMIX:
                    if (mix.ch_a < 0 || mix.ch_a >= ch_max_cur || ch_max_cur - 1 == 0) break;
                    ch_max_cur--;
                    break;

                case MIX_DOWNMIX_REST:
                    if (mix.ch_a < 0 || mix.ch_a >= ch_max_cur) break;
                    ch_max_cur = mix.ch_a + 1; /* simply clamp channels */
                    break;

                case MIX_UPMIX:
                    if (mix.ch_a < 0 || mix.ch_a > ch_max_cur) break; /* ch_a can be == max_cur, since we are inserting */
                    ch_max_cur++;
                    break;

                default:
                    break;
            }
        }

        vgmstream->output_channels = ch_max_cur;
    }
#endif

    if (current->sample_rate > 0)
        vgmstream->sample_rate = current->sample_rate;

    vgmstream->config_loop_count = current->config_loop_count;
    vgmstream->config_fade_time = current->config_fade_time;
    vgmstream->config_fade_delay = current->config_fade_delay;
    vgmstream->config_ignore_loop = current->config_ignore_loop;
    vgmstream->config_force_loop = current->config_force_loop;
    vgmstream->config_ignore_fade = current->config_ignore_fade;
}

/* ********************************** */

static void clean_filename(char * filename) {
    int i;
    size_t len;

    if (filename[0] == '\0')
        return;

    /* normalize paths */
    fix_dir_separators(filename);

    /* remove trailing spaces */
    len = strlen(filename);
    for (i = len-1; i > 0; i--) {
        if (filename[i] != ' ')
            break;
        filename[i] = '\0';
    }

}

static int get_double(const char * config, double *value) {
    int n;
    if (sscanf(config, "%lf%n", value,&n) != 1) {
        *value = 0;
        return 0;
    }
    return n;
}
static int get_int(const char * config, int *value) {
    int n;
    if (sscanf(config, "%i%n", value,&n) != 1) {
        *value = 0;
        return 0;
    }
    return n;
}

#ifdef VGMSTREAM_MIXING
static void add_mixing(txtp_entry* cfg, mix_config_data* mix, mix_command_t command) {
    if (cfg->mixing_count + 1 > TXTP_MIXING_MAX) {
        VGM_LOG("TXTP: too many mixes\n");
        return;
    }

    /* parsers reads ch1 = first, but for mixing code ch0 = first
     * (if parser reads ch0 here it'll becode -1 and ignored in code) */
    mix->ch_a--;
    mix->ch_b--;
    mix->command = command;
    cfg->mixing[cfg->mixing_count] = *mix; /* memcpy'ed */
    cfg->mixing_count++;
}
#endif


static void add_config(txtp_entry* current, txtp_entry* cfg, const char* filename) {
    strcpy(current->filename, filename);

    current->subsong = cfg->subsong;

    current->channel_mask = cfg->channel_mask;

    if (cfg->channel_mappings_on) {
        int ch;
        current->channel_mappings_on = cfg->channel_mappings_on;
        for (ch = 0; ch < 32; ch++) {
            current->channel_mappings[ch] = cfg->channel_mappings[ch];
        }
    }

#ifdef VGMSTREAM_MIXING
    //*current = *cfg; /* don't memcopy to allow list additions */

    if (cfg->mixing_count > 0) {
        int i;
        for (i = 0; i < cfg->mixing_count; i++) {
            current->mixing[current->mixing_count] = cfg->mixing[i];
            current->mixing_count++;
        }
    }
#endif

    current->config_loop_count = cfg->config_loop_count;
    current->config_fade_time = cfg->config_fade_time;
    current->config_fade_delay = cfg->config_fade_delay;
    current->config_ignore_loop = cfg->config_ignore_loop;
    current->config_force_loop = cfg->config_force_loop;
    current->config_ignore_fade = cfg->config_ignore_fade;

    current->sample_rate = cfg->sample_rate;

}

static int add_filename(txtp_header * txtp, char *filename, int is_default) {
    int i, n;
    txtp_entry cfg = {0};
    size_t range_start, range_end;
    const char separator = '#';


    //;VGM_LOG("TXTP: filename=%s\n", filename);

    /* parse config: file.ext#(command) */
    {
        char *config;

        /* find config start (filenames and config can contain multiple dots and #,
         * so this may be fooled by certain patterns of . and #) */
        config = strchr(filename, '.'); /* first dot (may be a false positive) */
        if (!config) /* extensionless */
            config = filename;
        config = strchr(config,separator); /* next should be config (hopefully right after extension) */
        if (!config) /* no config */
            config = filename;

        range_start = 0;
        range_end = 1;
        do {
            /* get config pointer but remove config from filename */
            config = strchr(config, separator);
            if (!config)
                continue;
            //;VGM_LOG("TXTP: config=%s\n", config);

            config[0] = '\0';
            config++;


            if (config[0] == 'c') {
                /* channel mask: file.ext#c1,2 = play channels 1,2 and mutes rest */
                int ch;

                config++;
                cfg.channel_mask = 0;
                while (sscanf(config, "%d%n", &ch,&n) == 1) {
                    if (ch > 0 && ch <= 32)
                        cfg.channel_mask |= (1 << (ch-1));

                    config += n;
                    if (config[0]== ',' || config[0]== '-') /* "-" for PowerShell, may have problems with "," */
                        config++;
                    else if (config[0] != '\0')
                        break;
                };
            }
            else if (config[0] == 'm') {
                /* channel mappings: file.ext#m1-2,3-4 = swaps channels 1<>2 and 3<>4 */
                int ch_from = 0, ch_to = 0;

                config++;
                cfg.channel_mappings_on = 1;

                while (config[0] != '\0') {
                    if (sscanf(config, "%d%n", &ch_from, &n) != 1)
                        break;
                    config += n;
                    if (config[0]== ',' || config[0]== '-')
                        config++;
                    else if (config[0] != '\0')
                        break;

                    if (sscanf(config, "%d%n", &ch_to, &n) != 1)
                        break;
                    config += n;
                    if (config[0]== ',' || config[0]== '-')
                        config++;
                    else if (config[0] != '\0')
                        break;

                    if (ch_from > 0 && ch_from <= 32 && ch_to > 0 && ch_to <= 32) {
                        cfg.channel_mappings[ch_from-1] = ch_to-1;
                    }
               }
            }
#ifdef VGMSTREAM_MIXING
            else if (config[0] == 'm') {
                /* channel mixing: file.ext#m(sub-command),(sub-command),etc */
                char cmd;

                config++;

                while (config[0] != '\0') {
                    mix_config_data mix = {0};

                    if (config[0]== ',') {
                        config++;
                        continue;
                    }

                    if (sscanf(config, "%d-%d%n", &mix.ch_a, &mix.ch_b, &n) == 2 && n != 0) {
                        add_mixing(&cfg, &mix, MIX_SWAP); /* N-M: swaps M with N */
                        config += n;
                        continue;
                    }

                    if ((sscanf(config, "%d+%d*%f%n", &mix.ch_a, &mix.ch_b, &mix.vol_a, &n) == 3 && n != 0) ||
                        (sscanf(config, "%d+%dx%f%n", &mix.ch_a, &mix.ch_b, &mix.vol_a, &n) == 3 && n != 0)) {
                        add_mixing(&cfg, &mix, MIX_ADD_VOLUME); /* N+M*V: mixes M * volume to N */
                        config += n;
                        continue;
                    }

                    if (sscanf(config, "%d+%d%n", &mix.ch_a, &mix.ch_b, &n) == 2 && n != 0) {
                        add_mixing(&cfg, &mix, MIX_ADD); /* N+M: mixes M to N */
                        config += n;
                        continue;
                    }

                    if ((sscanf(config, "%d*%f~%f@%f~%f%n", &mix.ch_a, &mix.vol_a, &mix.vol_b, &mix.pos_a, &mix.pos_b, &n) == 5 && n != 0) ||
                        (sscanf(config, "%dx%f~%f@%f~%f%n", &mix.ch_a, &mix.vol_a, &mix.vol_b, &mix.pos_a, &mix.pos_b, &n) == 5 && n != 0)) {
                        add_mixing(&cfg, &mix, MIX_CROSSFADE); /* N*V1~V2@P1~P2: fades from volume1 to 2 between position1 to 2 */
                        config += n;
                        continue;
                    }

                    if ((sscanf(config, "%d*%f%n", &mix.ch_a, &mix.vol_a, &n) == 2 && n != 0) ||
                        (sscanf(config, "%dx%f%n", &mix.ch_a, &mix.vol_a, &n) == 2 && n != 0)) {
                        add_mixing(&cfg, &mix, MIX_VOLUME); /* N*V: changes volume of N */
                        config += n;
                        continue;
                    }

                    if (sscanf(config, "%d%c%n", &mix.ch_a, &cmd, &n) == 2 && n != 0 && cmd == 'D') {
                        add_mixing(&cfg, &mix, MIX_DOWNMIX_REST); /* ND: downmix N and all following channels */
                        config += n;
                        continue;
                    }

                    if (sscanf(config, "%d%c%n", &mix.ch_a, &cmd, &n) == 2 && n != 0 && cmd == 'd') {
                        add_mixing(&cfg, &mix, MIX_DOWNMIX);/* Nd: downmix N only */
                        config += n;
                        continue;
                    }

                    if (sscanf(config, "%d%c%n", &mix.ch_a, &cmd, &n) == 2 && n != 0 && cmd == 'u') {
                        add_mixing(&cfg, &mix, MIX_UPMIX); /* Nu: upmix N */
                        config += n;
                        continue;
                    }

                    break; /* unknown/mix end */
               }
            }
#endif
            else if (config[0] == 's' || (config[0] >= '0' && config[0] <= '9')) {
                /* subsongs: file.ext#s2 = play subsong 2, file.ext#2~10 = play subsong range */
                int subsong_start = 0, subsong_end = 0;

                if (config[0]== 's')
                    config++;
                if (sscanf(config, "%d~%d", &subsong_start, &subsong_end) == 2) {
                    if (subsong_start > 0 && subsong_end > 0) {
                        range_start = subsong_start-1;
                        range_end = subsong_end;
                    }
                }
                else if (sscanf(config, "%u", &subsong_start) == 1) {
                    if (subsong_start > 0) {
                        range_start = subsong_start-1;
                        range_end = subsong_start;
                    }
                }
                else {
                    config = NULL; /* wrong config, ignore */
                }
            }
            else if (config[0] == 'i') {
                config++;
                cfg.config_ignore_loop = 1;
            }
            else if (config[0] == 'E') {
                config++;
                cfg.config_force_loop = 1;
            }
            else if (config[0] == 'F') {
                config++;
                cfg.config_ignore_fade = 1;
            }
            else if (config[0] == 'l') {
                config++;
                config += get_double(config, &cfg.config_loop_count);
            }
            else if (config[0] == 'f') {
                config++;
                config += get_double(config, &cfg.config_fade_time);
            }
            else if (config[0] == 'd') {
                config++;
                config += get_double(config, &cfg.config_fade_delay);
            }
            else if (config[0] == 'h') {
                config++;
                config += get_int(config, &cfg.sample_rate);
            }
            else if (config[0] == ' ') {
                continue; /* likely a comment, find next # */
            }
            else {
                //;VGM_LOG("TXTP: unknown command '%c'\n", config[0]);
                break; /* also possibly a comment too */
            }

        } while (config != NULL);

        //;VGM_LOG("TXTP: config: range %i~%i, mask=%x\n", range_start, range_end, channel_mask);
    }


    clean_filename(filename);
    //;VGM_LOG("TXTP: clean filename='%s'\n", filename);

    /* config that applies to all files */
    if (is_default) {
        txtp->default_entry_set = 1;
        add_config(&txtp->default_entry, &cfg, filename);
        return 1;
    }

    /* add filenames */
    for (i = range_start; i < range_end; i++){
        txtp_entry *current;

        /* resize in steps if not enough */
        if (txtp->entry_count+1 > txtp->entry_max) {
            txtp_entry *temp_entry;

            txtp->entry_max += 5;
            temp_entry = realloc(txtp->entry, sizeof(txtp_entry) * txtp->entry_max);
            if (!temp_entry) goto fail;
            txtp->entry = temp_entry;
        }

        /* new entry */
        current = &txtp->entry[txtp->entry_count];
        memset(current,0, sizeof(txtp_entry));
        cfg.subsong = (i+1);

        add_config(current, &cfg, filename);

        txtp->entry_count++;
    }

    return 1;
fail:
    return 0;
}

static int parse_num(const char * val, uint32_t * out_value) {
    int hex = (val[0]=='0' && val[1]=='x');
    if (sscanf(val, hex ? "%x" : "%u", out_value)!=1)
        goto fail;

    return 1;
fail:
    return 0;
}

static int parse_keyval(txtp_header * txtp, const char * key, const char * val) {
    //;VGM_LOG("TXTP: key=val '%s'='%s'\n", key,val);

    if (0==strcmp(key,"loop_start_segment")) {
        if (!parse_num(val, &txtp->loop_start_segment)) goto fail;
    }
    else if (0==strcmp(key,"loop_end_segment")) {
        if (!parse_num(val, &txtp->loop_end_segment)) goto fail;
    }
    else if (0==strcmp(key,"mode")) {
        if (0==strcmp(val,"layers")) {
            txtp->is_layered = 1;
        }
        else {
            goto fail;
        }
    }
    else if (0==strcmp(key,"loop_mode")) {
        if (0==strcmp(val,"keep")) {
            txtp->is_loop_keep = 1;
        }
        else {
            goto fail;
        }
    }
    else if (0==strcmp(key,"commands")) {
        char val2[TXT_LINE_MAX];
        strcpy(val2, val); /* copy since val is modified here but probably not important */
        if (!add_filename(txtp, val2, 1)) goto fail;
    }
    else {
        goto fail;
    }

    return 1;
fail:
    VGM_LOG("TXTP: error while parsing key=val '%s'='%s'\n", key,val);
    return 0;
}

static txtp_header* parse_txtp(STREAMFILE* streamFile) {
    txtp_header* txtp = NULL;
    off_t txt_offset = 0x00;
    off_t file_size = get_streamfile_size(streamFile);


    txtp = calloc(1,sizeof(txtp_header));
    if (!txtp) goto fail;


    /* empty file: use filename with config (ex. "song.ext#3.txtp") */
    if (get_streamfile_size(streamFile) == 0) {
        char filename[PATH_LIMIT] = {0};
        char* ext;
        get_streamfile_filename(streamFile, filename,PATH_LIMIT);

        /* remove ".txtp" */
        ext = strrchr(filename,'.');
        if (!ext) goto fail; /* ??? */
        ext[0] = '\0';

        if (!add_filename(txtp, filename, 0))
            goto fail;

        return txtp;
    }


    /* skip BOM if needed */
    if ((uint16_t)read_16bitLE(0x00, streamFile) == 0xFFFE || (uint16_t)read_16bitLE(0x00, streamFile) == 0xFEFF)
        txt_offset = 0x02;

    /* read lines */
    while (txt_offset < file_size) {
        char line[TXT_LINE_MAX] = {0};
        char key[TXT_LINE_MAX] = {0}, val[TXT_LINE_MAX] = {0}; /* at least as big as a line to avoid overflows (I hope) */
        char filename[TXT_LINE_MAX] = {0};
        int ok, bytes_read, line_done;

        bytes_read = get_streamfile_text_line(TXT_LINE_MAX,line, txt_offset,streamFile, &line_done);
        if (!line_done) goto fail;

        txt_offset += bytes_read;

        /* get key/val (ignores lead/trail spaces, stops at space/separator) */
        ok = sscanf(line, " %[^ \t#=] = %[^ \t\r\n] ", key,val);
        if (ok == 2) { /* no key=val */
            if (!parse_keyval(txtp, key, val)) /* read key/val */
                goto fail;
            continue;
        }

        /* must be a filename (only remove spaces from start/end, as filenames con contain mid spaces/#/etc) */
        ok = sscanf(line, " %[^\t\r\n] ", filename);
        if (ok != 1) /* not a filename either */
            continue;
        if (filename[0] == '#')
            continue; /* simple comment */

        /* filename with config */
        if (!add_filename(txtp, filename, 0))
            goto fail;
    }


    return txtp;
fail:
    clean_txtp(txtp);
    return NULL;
}

static void clean_txtp(txtp_header* txtp) {
    if (!txtp)
        return;

    free(txtp->entry);
    free(txtp);
}