#include <math.h>
#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>
#include <limits.h>
#include <string.h>
#include "jl_mem.h"
#include "soundfile.h"
#include "sample.h"
#include "fx.h"

static bool starts_with(char *s, char *prefix)
{
    int n = strlen(prefix);
    if(n > strlen(s)) {
        return false;
    }

    for(int i = 0; i < n; ++i) {
        if(s[i] != prefix[i]) {
            return false;
        }
    }

    return true;
}

static void fsample_apply_effect(FSample *s, char *txt)
{
    // Attempt to parse each effect until one works.
    if(starts_with(txt, "amp(")) {
        double gain;
        if(sscanf(txt, "amp(%lf)", &gain) != 1) {
            goto apply_fx_err;
        }
        fx_amp(s, gain);
    }
    else if(starts_with(txt, "balance(")) {
        double balance;
        if(sscanf(txt, "balance(%lf)", &balance) != 1) {
            goto apply_fx_err;
        }
        fx_balance(s, balance);
    }
    else if(starts_with(txt, "divide_rms(")) {
        double t_ms;
        if(sscanf(txt, "divide_rms(%lf)", &t_ms) != 1) {
            goto apply_fx_err;
        }
        fx_divide_rms(s, t_ms);
    }
    else if(starts_with(txt, "fade_in(")) {
        double t_ms;
        if(sscanf(txt, "fade_in(%lf)", &t_ms) != 1) {
            goto apply_fx_err;
        }
        fx_fade_in(s, t_ms);
    }
    else if(starts_with(txt, "ir(")) {
        char path[MAX_FX_LINE];
        double mix;
        if(sscanf(txt, "ir(%[^,], %lf)", path, &mix) != 2) {
            goto apply_fx_err;
        }
        fx_ir(s, path, mix);
    }
    else if(starts_with(txt, "mono()")) {
        fx_mono(s);
    }
    else if(starts_with(txt, "pan(")) {
        double pan;
        if(sscanf(txt, "pan(%lf)", &pan) != 1) {
            goto apply_fx_err;
        }
        fx_pan(s, pan);
    }
    else if(starts_with(txt, "pre_cut(")) {
        double pct, fade_ms;
        if(sscanf(txt, "pre_cut(%lf, %lf)", &pct, &fade_ms) != 2) {
            goto apply_fx_err;
        }
        fx_pre_cut(s, pct, fade_ms);
    }
    else if(starts_with(txt, "playback_speed(")) {
        double speed;
        if(sscanf(txt, "playback_speed(%lf)", &speed) != 1) {
            goto apply_fx_err;
        }
        fx_playback_speed(s, speed);
    }
    else if(starts_with(txt, "pre_delay(")) {
        double left_ms, right_ms;
        if(sscanf(txt, "pre_delay(%lf, %lf)", &left_ms, &right_ms) != 2) {
            goto apply_fx_err;
        }
        fx_pre_delay(s, left_ms, right_ms);
    }
    else if(starts_with(txt, "rc_highpass(")) {
        double freq;
        int order;
        if(sscanf(txt, "rc_highpass(%lf, %d)", &freq, &order) != 2) {
            goto apply_fx_err;
        }
        fx_rc_highpass(s, freq, order);
    }
    else if(starts_with(txt, "rc_lowpass(")) {
        double freq;
        int order;
        if(sscanf(txt, "rc_lowpass(%lf, %d)", &freq, &order) != 2) {
            goto apply_fx_err;
        }
        fx_rc_lowpass(s, freq, order);
    }
    else if(starts_with(txt, "rc_highshelf(")) {
        double freq, gain;
        int order;
        if(sscanf(txt, "rc_highshelf(%lf, %d, %lf)", &freq, &order, &gain) != 3) {
            goto apply_fx_err;
        }
        fx_rc_highshelf(s, freq, order, gain);
    }
    else if(starts_with(txt, "rc_lowshelf(")) {
        double freq, gain;
        int order;
        if(sscanf(txt, "rc_lowshelf(%lf, %d, %lf)", &freq, &order, &gain) != 3) {
            goto apply_fx_err;
        }
        fx_rc_lowshelf(s, freq, order, gain);
    }
    else if(starts_with(txt, "stereo_width(")) {
        double width;
        if(sscanf(txt, "stereo_width(%lf)", &width) != 1) {
            goto apply_fx_err;
        }
        fx_stereo_width(s, width);
    }
    else {
        printf("Unknown effect: %s\n", txt);
    }

    return;

apply_fx_err:
    printf("Parsing error: %s\n", txt);
    exit(1);
}

void fsample_load(FSample *s, char *path, SoundConfig *conf, int buf_size)
{
    s->len = soundfile_load_stereo(path, &s->L, &s->R);

    // Apply global pre effects.
    for(int i = 0; conf->global_fx_pre[i][0] != '\0'; ++i) {
        fsample_apply_effect(s, conf->global_fx_pre[i]);
    }

    // Apply pre effects.
    for(int i = 0; conf->fx_pre[i][0] != '\0'; ++i) {
        fsample_apply_effect(s, conf->fx_pre[i]);
    }

    // Apply post effets.
    for(int i = 0; conf->fx_post[i][0] != '\0'; ++i) {
        fsample_apply_effect(s, conf->fx_post[i]);
    }

    // Apply global post effects.
    for(int i = 0; conf->global_fx_post[i][0] != '\0'; ++i) {
        fsample_apply_effect(s, conf->global_fx_post[i]);
    }
}

void fsample_set_data(FSample *s, float *L, float *R, int len)
{
    jl_free(s->L);
    jl_free(s->R);
    s->L = L;
    s->R = R;
    s->len = len;
}

double fsample_max_amp(FSample *s)
{
    double max = 0;
    for(int i = 0; i < s->len; i++) {
        if(max < s->L[i]) {
            max = s->L[i];
        } else if(max < -s->L[i]) {
            max = -s->L[i];
        }

        if(max < s->R[i]) {
            max = s->R[i];
        } else if(max < -s->R[i]) {
            max = -s->R[i];
        }
    }
    return max;
}

void fsample_free(FSample *s)
{
    jl_free(s->L);
    jl_free(s->R);
    s->R = s->L = NULL;
    s->len = 0;
}