#include <sys/stat.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "config.h"

const char DEFAULT_CONFIG[] =
  "# fhvkov - forza horizon overlay (vulkan layer)\n"
  "# positions and sizes are fractions of the game window;\n"
  "# _x/_y are gauge centers. this file is re-read every second,\n"
  "# so you can edit and save while driving.\n"
  "port=9999\n"
  "units=kmh\n"
  "keep=0\n"
  "scale=1.0\n"
  "# needle motion blur: seconds of smear (try 0.06-0.15), 0 = off\n"
  "blur=0.10\n"
  "\n"
  "tach_x=0.878\n"
  "tach_y=0.830\n"
  "tach_r=0.130\n"
  "flash_needle=1\n"
  "# whether to scale max rpm based on rpm reached by car\n"
  "autoscale_rpm=1\n"
  "# offset from max rpm at which needle starts flashing red\n"
  "rpm_off=800.0\n"
  "\n"
  "show_boost=1\n"
  "boost_x=0.775\n"
  "boost_y=0.907\n"
  "boost_r=0.060\n"
  "\n"
  "# lamps: abs, tcs (wheel slip) and tcs launch-control flash\n"
  "show_abs=1\n"
  "show_tcs=0\n"
  "# enabling LC shows the \"tcs\" lamp\n"
  "show_lc=1\n"
  "show_tires=1\n"
  "tire_x=0.970\n"
  "tire_y=0.710\n"
  "tire_sc=1.0\n";

void config_defaults( CONFIG* c ) {
  c->port  = 9999;
  c->units = 0;
  c->keep  = 0;
  c->tach_x = 0.878; c->tach_y = 0.830; c->tach_r = 0.130;
  c->scale = 1.0;
  c->blur  = 0.10;
  c->show_boost = 1;
  c->boost_x = 0.775; c->boost_y = 0.907; c->boost_r = 0.060;
  c->show_abs = 1; c->show_tcs = 1; c->show_lc = 1;
  c->show_tires = 1;
  c->tire_x = 0.97; c->tire_y = 0.71, c->tire_sc = 1.0;
  c->flash_needle = 1;
  c->autoscale_rpm = 1;
  c->rpm_off = 800.0;
}

void config_resolve_path( CONFIG* c ) {
  const char* env = getenv( "FHRPM_CONFIG" );
  if( env ) {
    snprintf( c->path, sizeof( c->path ), "%s", env );
    return;
  }
  const char* home = getenv( "HOME" );
  if( !home )
    home = ".";
  snprintf( c->path, sizeof( c->path ), "%s/.config/fhvkov/fhvkov.conf", home );
}

void config_write_default( const CONFIG* c ) {
  char dir[512];
  const char* home = getenv( "HOME" );
  if( home ) {
    snprintf( dir, sizeof( dir ), "%s/.config", home );
    mkdir( dir, 0755 );
    snprintf( dir, sizeof( dir ), "%s/.config/fhvkov", home );
    mkdir( dir, 0755 );
  }

  FILE* f = fopen( c->path, "w" );
  if( !f )
    return;
  defer( fclose( f ) );

  fwrite( DEFAULT_CONFIG, 1, sizeof( DEFAULT_CONFIG ) - 1, f );
  dlog( "fhvkov: wrote default config to %s\n", c->path );
}

void config_parse_line( CONFIG* c, char* key, char* val ) {
  if(      !strcmp( key, "port" ) )          c->port = atoi( val );
  else if( !strcmp( key, "units" ) )         c->units = !strcmp( val, "mph" );
  else if( !strcmp( key, "keep" ) )          c->keep = atoi( val );
  else if( !strcmp( key, "tach_x" ) )        c->tach_x = atof( val );
  else if( !strcmp( key, "tach_y" ) )        c->tach_y = atof( val );
  else if( !strcmp( key, "tach_r" ) )        c->tach_r = atof( val );
  else if( !strcmp( key, "show_boost" ) )    c->show_boost = atoi( val );
  else if( !strcmp( key, "boost_x" ) )       c->boost_x = atof( val );
  else if( !strcmp( key, "boost_y" ) )       c->boost_y = atof( val );
  else if( !strcmp( key, "boost_r" ) )       c->boost_r = atof( val );
  else if( !strcmp( key, "scale" ) )         c->scale = atof( val );
  else if( !strcmp( key, "blur" ) )          c->blur = atof( val );
  else if( !strcmp( key, "show_abs" ) )      c->show_abs = atoi( val );
  else if( !strcmp( key, "show_tcs" ) )      c->show_tcs = atoi( val );
  else if( !strcmp( key, "show_lc" ) )       c->show_lc = atoi( val );
  else if( !strcmp( key, "show_tires" ) )    c->show_tires = atoi( val );
  else if( !strcmp( key, "tire_x" ) )        c->tire_x = atof( val );
  else if( !strcmp( key, "tire_y" ) )        c->tire_y = atof( val );
  else if( !strcmp( key, "tire_sc" ) )       c->tire_sc = atof( val );
  else if( !strcmp( key, "flash_needle" ) )  c->flash_needle = atoi( val );
  else if( !strcmp( key, "autoscale_rpm" ) ) c->autoscale_rpm = atoi( val );
  else if( !strcmp( key, "rpm_off" ) )       c->rpm_off = atof( val );
}

STAT config_load( CONFIG* c ) {
  FILE* f = fopen( c->path, "r" );
  if( !f )
    return STAT_ERR;
  defer( fclose( f ) );

  char line[256];
  while( fgets( line, sizeof( line ), f ) ) {
    char* p = line;
    while( *p == ' ' || *p == '\t' )
      p++;
    if( *p == '#' || *p == '\n' ||* p == 0 )
      continue;

    char* eq = strchr( p, '=' );
    if( !eq )
      continue;
    *eq = 0;

    char* key = p, *val = eq + 1;
    char* nl = strchr( val, '\n' );
    if( nl )
      *nl = 0;
    char* e = key + strlen( key );
    while( e > key && ( e[-1] == ' ' || e[-1] == '\t' ) )
      *--e = 0;

    config_parse_line( c, key, val );
  }

  struct stat st;
  if( stat( c->path, &st ) == 0 )
    c->mtime = st.st_mtime;
  return STAT_OK;
}

void config_init( CONFIG* c ) {
  config_defaults( c );
  config_resolve_path( c );
  if( !OK( config_load( c ) ) ) {
    config_write_default( c );
    config_load( c );
  }
}

U8 config_poll( CONFIG* c ) {
  struct stat st;
  if( stat( c->path, &st ) != 0 )
    return 0;
  if( st.st_mtime == c->mtime )
    return 0;

  CONFIG fresh;
  config_defaults( &fresh );
  memcpy( fresh.path, c->path, sizeof( fresh.path ) );
  if( !OK( config_load( &fresh ) ) )
    return 0;

  fresh.port = c->port;
  *c = fresh;
  dlog( "fhvkov: config reloaded\n" );
  return 1;
}