/*
  LibRCC - module responsible for library initialization 

  Copyright (C) 2005-2018 Suren A. Chilingaryan <csa@suren.me>

  This library is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License version 2.1 or later
  as published by the Free Software Foundation.

  This library is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License 
  for more details.

  You should have received a copy of the GNU Lesser General Public License 
  along with this program; if not, write to the Free Software Foundation, Inc.,
  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <errno.h>

#include <string.h>
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */


#include "../config.h"

#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */

#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif /* HAVE_SYS_TYPES_H */
#ifdef HAVE_SYS_STAT_H
# include <sys/stat.h>
#endif /* HAVE_SYS_STAT_H */

#ifdef HAVE_PWD_H
# include <pwd.h>
#endif /* HAVE_PWD_H */

#ifdef HAVE_SYS_FILE_H
# include <sys/file.h>
#endif /* HAVE_SYS_FILE_H */


#include "internal.h"
#include "rccconfig.h"
#include "rccenca.h"
#include "rcclist.h"
#include "plugin.h"
#include "engine.h"
#include "rccxml.h"
#include "rccexternal.h"
#include "rcctranslate.h"
#include "rcclock.h"
#include "rcchome.h"

static int initialized = 0;
rcc_context rcc_default_ctx = NULL;
static rcc_compiled_configuration_s compiled_configuration;

rcc_compiled_configuration rccGetCompiledConfiguration() {
    compiled_configuration.flags = 0;
#ifdef HAVE_RCD
    compiled_configuration.flags|=RCC_CC_FLAG_HAVE_RCD;
#endif /* HAVE_RCD */
#ifdef HAVE_ENCA
    compiled_configuration.flags|=RCC_CC_FLAG_HAVE_ENCA;
#endif /* HAVE_ENCA */
#ifdef HAVE_DLOPEN
    compiled_configuration.flags|=RCC_CC_FLAG_HAVE_DYNAMIC_ENGINES;
#endif /* HAVE_DLOPEN */
#ifdef HAVE_DB_H
    compiled_configuration.flags|=RCC_CC_FLAG_HAVE_BERKLEY_DB;
#endif /* HAVE_DB_H */
#ifdef HAVE_LIBTRANSLATE
    compiled_configuration.flags|=RCC_CC_FLAG_HAVE_LIBTRANSLATE;
#endif /* HAVE_LIBTRANSLATE */

    return &compiled_configuration;
}

int rccInit(void) {
    int err;
    unsigned long i, rpos;
    
    if (initialized) return 0;
    
    rccHomeSet();
    
    memcpy(rcc_default_languages, rcc_default_languages_embeded, (RCC_MAX_LANGUAGES + 1)*sizeof(rcc_language));
    memcpy(rcc_default_aliases, rcc_default_aliases_embeded, (RCC_MAX_ALIASES + 1)*sizeof(rcc_language_alias));
    memcpy(rcc_default_relations, rcc_default_relations_embeded, (RCC_MAX_RELATIONS + 1)*sizeof(rcc_language_relation));
    memcpy(rcc_option_descriptions, rcc_option_descriptions_embeded, (RCC_MAX_OPTIONS + 1)*sizeof(rcc_option_description));

#ifdef HAVE_LIBTRANSLATE
    rccExternalInit();
#endif /* HAVE_LIBTRANSLATE */    

    for (rpos=0;rcc_default_relations[rpos].lang;rpos++);
    for (i=0;rcc_default_languages[i].sn;i++) {
	if (!strcasecmp(rcc_default_languages[i].sn, rcc_default_language_sn)) continue;
	if (!strcasecmp(rcc_default_languages[i].sn, rcc_disabled_language_sn)) continue;
	if (!strcasecmp(rcc_default_languages[i].sn, rcc_english_language_sn)) continue;

	rcc_default_relations[rpos].lang = rcc_default_languages[i].sn;
	rcc_default_relations[rpos++].parent = rcc_english_language_sn;
    }
    rcc_default_relations[rpos].lang = NULL;
    rcc_default_relations[rpos].parent = NULL;

    err = rccPluginInit();
    if (!err) err = rccTranslateInit();
    if (!err) err = rccXmlInit(1);
    if (!err) err = rccEngineInit();

    if (err) {
	rccFree();
	return err;
    }

    initialized = 1;

    return 0;
}

void rccFree(void) {
    if (rcc_default_ctx) {
	rccFreeContext(rcc_default_ctx);
	rcc_default_ctx = NULL;
    }
    
    rccEngineFree();
	// Clean-up might cause problems if LibXML2 is also used by an application outside of LibXML2...
	// According to LibXML2 developers, usage of this function is not advised, cleanup only should be performed on application exit, and is done libxml2 automatically.
    //rccXmlFree();
    rccTranslateFree();
    rccPluginFree();

    rccExternalFree();

    rccHomeFree();

    initialized = 0;
}

rcc_context rccCreateContext(const char *locale_variable, unsigned int max_languages, unsigned int max_classes, rcc_class_ptr defclasses, rcc_init_flags flags) {
    unsigned int i;
    
    rcc_context ctx;
    rcc_language_ptr *languages;
    rcc_language_internal *ilang;
    rcc_class_ptr *classes;
    rcc_class_internal *iclass;
    rcc_language_config configs;
    rcc_iconv *from;
    rcc_mutex mutex;

    if (!initialized) return NULL;
    
    if (!max_languages) {
	if (flags&RCC_FLAG_NO_DEFAULT_CONFIGURATION) max_languages = RCC_MAX_LANGUAGES;
	else {
	    for (i=0;rcc_default_languages[i].sn;i++);
	    max_languages = i;
	}
    }
    
    if (!max_classes) {
	if (defclasses) {
	    for (i=0;defclasses[i].name;i++);
	    max_classes = i;
	} else max_classes = RCC_MAX_CLASSES;
    }

    ctx = (rcc_context)malloc(sizeof(struct rcc_context_t));
    languages = (rcc_language_ptr*)malloc((max_languages+1)*sizeof(rcc_language_ptr));
    classes = (rcc_class_ptr*)malloc((max_classes+1)*sizeof(rcc_class_ptr));
    from = (rcc_iconv*)malloc((max_classes)*sizeof(rcc_iconv));
    ilang = (rcc_language_internal*)malloc((max_languages+1)*sizeof(rcc_language_internal));
    iclass = (rcc_class_internal*)malloc((max_classes+1)*sizeof(rcc_class_internal));
    mutex = rccMutexCreate();

    configs = (rcc_language_config)malloc((max_languages)*sizeof(struct rcc_language_config_t));
    
    if ((!ctx)||(!languages)||(!classes)||(!from)||(!ilang)||(!iclass)||(!mutex)||(!configs)) {
	if (mutex) rccMutexFree(mutex);
	if (from) free(from);
	if (configs) free(configs);
	if (classes) free(classes);
	if (languages) free(languages);
	if (ilang) free(ilang);
	if (iclass) free(iclass);
	if (ctx) free(ctx);
	return NULL;
    }

    ctx->configuration_lock = 0;
    
    ctx->mutex = mutex;
    
    ctx->db4ctx = NULL;

    ctx->aliases[0] = NULL;
    for (i=0;rcc_default_aliases[i].alias;i++)
	rccRegisterLanguageAlias(ctx, rcc_default_aliases + i);
    
    ctx->ilang = ilang;
    ctx->iclass = iclass;
    
    ctx->languages = languages;
    ctx->max_languages = max_languages;
    ctx->n_languages = 0;
    languages[0] = NULL;

    ctx->classes = classes;
    ctx->max_classes = max_classes;
    ctx->n_classes = 0;
    classes[0] = NULL;

    ctx->lastprefix[0] = 0;
    
    ctx->iconv_from = from;
    for (i=0;i<max_classes;i++) from[i] = NULL;
    for (i=0;i<RCC_MAX_CHARSETS;i++) ctx->iconv_auto[i] = NULL;
    
    ctx->configs = configs;
    for (i=0;i<max_languages;i++)
	configs[i].charset = NULL;

    ctx->current_language = 0;
    ctx->default_language = 0;

    if (locale_variable) {
	if (strlen(locale_variable)>=RCC_MAX_VARIABLE_CHARS) {
	    rccFreeContext(ctx);
	    return NULL;
	}
	strcpy(ctx->locale_variable, locale_variable);
    } else {
	strcpy(ctx->locale_variable, RCC_LOCALE_VARIABLE);
    }

    for (i=0;i<RCC_MAX_OPTIONS;i++) rccOptionSetDefault(ctx, (rcc_option)i);
    
    if (flags&RCC_FLAG_NO_DEFAULT_CONFIGURATION) {
	rccRegisterLanguage(ctx, rcc_default_languages);
	ctx->current_config = NULL;
    } else {
	for (i=0;rcc_default_languages[i].sn;i++)
	    rccRegisterLanguage(ctx, rcc_default_languages+i);

	if (max_languages < i) {
	    rccFreeContext(ctx);
	    return NULL;
	}

	for (i=0;rcc_default_relations[i].lang;i++)
	    rccRegisterLanguageRelation(ctx, rcc_default_relations+i);
	
	ctx->current_config = rccGetCurrentConfig(ctx);
    } 
    
    if (defclasses) {
	for (i=0;defclasses[i].name;i++)
	    rccRegisterClass(ctx, defclasses+i);

	if (max_classes < i) {
	    rccFreeContext(ctx);
	    return NULL;
	}	    
    }

    ctx->configure = 1;
    
    return ctx;
}

int rccInitDefaultContext(const char *locale_variable, unsigned int max_languages, unsigned int max_classes, rcc_class_ptr defclasses, rcc_init_flags flags) {
    if (!initialized) return -1;
    if (rcc_default_ctx) rccFreeContext(rcc_default_ctx);
    rcc_default_ctx = rccCreateContext(locale_variable, max_languages, max_classes, defclasses, flags);
    if (rcc_default_ctx) return 0;
    return -1;
}


static void rccFreeIConv(rcc_context ctx) {
    unsigned int i;
    
    if ((!ctx)||(!ctx->iconv_from)) return;

    for (i=0;i<ctx->n_classes;i++) {
	if (ctx->iconv_from[i]) {
	    rccIConvClose(ctx->iconv_from[i]);
	    ctx->iconv_from[i] = NULL;
	}
    }
    for (i=0;i<RCC_MAX_CHARSETS;i++) {
	if (ctx->iconv_auto[i]) {
	    rccIConvClose(ctx->iconv_auto[i]);
	    ctx->iconv_auto[i] = NULL;
	}
    }    
}

void rccFreeContext(rcc_context ctx) {
    unsigned int i;
    
    if (ctx) {
	if (ctx->db4ctx) rccDb4FreeContext(ctx->db4ctx);
	rccFreeIConv(ctx);
	if (ctx->iconv_from) free(ctx->iconv_from);
	
	if (ctx->configs) {
	    for (i=0;i<ctx->max_languages;i++)
		rccConfigClear(ctx->configs+i);
	    free(ctx->configs);
	}
	if (ctx->iclass) free(ctx->iclass);
	if (ctx->classes) free(ctx->classes);
	if (ctx->ilang) free(ctx->ilang);
	if (ctx->languages) free(ctx->languages);
	if (ctx->mutex) rccMutexFree(ctx->mutex);
	free(ctx);
    }
}

int rccInitDb4(rcc_context ctx, const char *name, rcc_db4_flags flags) {
    size_t size;
    char *dbname;
    
    if (!ctx) {
	if (rcc_default_ctx) ctx = rcc_default_ctx;
	else return -1;
    }

    if (!name) name = "default";

    size = strlen(rcc_home_dir) + strlen(name) + 32;
    dbname = (char*)malloc(size*sizeof(char));
    if (!dbname) return -1;

    sprintf(dbname,"%s/.rcc/",rcc_home_dir);
#ifdef _WIN32
    mkdir(dbname);
#else
    mkdir(dbname, 00755);
#endif
    
    sprintf(dbname,"%s/.rcc/%s.db/",rcc_home_dir,name);
#ifdef _WIN32
    mkdir(dbname);
#else
    mkdir(dbname, 00755);
#endif

    ctx->db4ctx = rccDb4CreateContext(dbname, flags);
    free(dbname);	
    
    if (!ctx->db4ctx) return -1;

    return 0;
}

int rccLockConfiguration(rcc_context ctx, unsigned int lock_code) {
    if (!ctx) {
	if (rcc_default_ctx) ctx = rcc_default_ctx;
	else return -1;
    }

    if (ctx->configuration_lock) return -1;
    ctx->configuration_lock = lock_code;
    return 0;
}

int rccUnlockConfiguration(rcc_context ctx, unsigned int lock_code) {
    if (!ctx) {
	if (rcc_default_ctx) ctx = rcc_default_ctx;
	else return -1;
    }

    if (ctx->configuration_lock != lock_code) return -1;
    ctx->configuration_lock = 0;
    return 0;    
}

rcc_language_id rccRegisterLanguage(rcc_context ctx, rcc_language *language) {
    unsigned int i;
    if (!ctx) {
	if (rcc_default_ctx) ctx = rcc_default_ctx;
	else return (rcc_language_id)-1;
    }
    if (!language) return (rcc_language_id)-1;
    if (ctx->configuration_lock) return (rcc_language_id)-1;
    
    if (ctx->n_languages == ctx->max_languages) return (rcc_language_id)-1;
    
    memcpy(ctx->ilang + ctx->n_languages, language, sizeof(rcc_language));
    ctx->ilang[ctx->n_languages].parents[0] = (rcc_language_id)-1;
    ctx->ilang[ctx->n_languages].latin = 0;
    
    for (i=0;language->charsets[i];i++)
	if ((strstr(language->charsets[i],"8859"))&&(language->charsets[i][strlen(language->charsets[i])-1]=='1')) {
	    ctx->ilang[ctx->n_languages].latin = 1;
	    break;
	}

    if ((i==1)&&(!language->charsets[1])&&(rccIsUTF8(language->charsets[0])))
	    ctx->ilang[ctx->n_languages].latin = 1;

    ctx->languages[ctx->n_languages] = (rcc_language_ptr)(ctx->ilang + ctx->n_languages);
    ctx->languages[++ctx->n_languages] = NULL;
    
    if (!ctx->current_language)
	ctx->current_config = rccGetCurrentConfig(ctx);
    
    return ctx->n_languages-1;
}

rcc_charset_id rccLanguageRegisterCharset(rcc_language *language, rcc_charset charset) {
    unsigned int i;
    
    if ((!language)||(!charset)) return (rcc_charset_id)-1;
    for (i=0;language->charsets[i];i++);
    if (i>=RCC_MAX_CHARSETS) return (rcc_charset_id)-1;

    if ((strstr(charset,"8859"))&&(charset[strlen(charset)-1]=='1')) 
	((rcc_language_internal*)language)->latin = 1;
    
    language->charsets[i++] = charset;
    language->charsets[i] = NULL;
    return i-1;
}

rcc_engine_id rccLanguageRegisterEngine(rcc_language *language, rcc_engine *engine) {
    unsigned int i;
    
    if ((!language)||(!engine)) return (rcc_engine_id)-1;
    for (i=0;language->engines[i];i++);
    if (i>=RCC_MAX_ENGINES) return (rcc_engine_id)-1;
    language->engines[i++] = engine;
    language->engines[i] = NULL;
    return i-1;
}

rcc_alias_id rccRegisterLanguageAlias(rcc_context ctx, rcc_language_alias *alias) {
    unsigned int i;
    
    if (!ctx) {
	if (rcc_default_ctx) ctx = rcc_default_ctx;
	else return (rcc_alias_id)-1;
    }
    if (!alias) return (rcc_alias_id)-1;
    
    for (i=0;ctx->aliases[i];i++)
    if (i>=RCC_MAX_ALIASES) return (rcc_alias_id)-1;
    
    ctx->aliases[i++] = alias;
    ctx->aliases[i] = NULL;

    return i-1;
}

rcc_relation_id rccRegisterLanguageRelation(rcc_context ctx, rcc_language_relation *relation) {
    unsigned int i;
    rcc_language_id language_id;
    const char *lang;
    const char *parent;
    rcc_language_id *list;
    
    if (!ctx) {
	if (rcc_default_ctx) ctx = rcc_default_ctx;
	else return (rcc_alias_id)-1;
    }
    if (!relation) return (rcc_relation_id)-1;

    lang = relation->lang;
    parent = relation->parent;
    if ((!lang)||(!parent)||(!strcasecmp(lang,parent))) return (rcc_relation_id)-1;
    
    language_id = rccGetLanguageByName(ctx, lang);
    if (language_id == (rcc_language_id)-1) return (rcc_relation_id)-1;
    

    list = ((rcc_language_internal*)ctx->languages[language_id])->parents;

    language_id = rccGetLanguageByName(ctx, parent);
    if (language_id == (rcc_language_id)-1) return (rcc_relation_id)0;
    
    for (i=0;list[i]!=(rcc_language_id)-1;i++)
	if (list[i] == language_id) return (rcc_relation_id)0;

    if (i<RCC_MAX_LANGUAGE_PARENTS) {
	list[i++] = language_id;
    	list[i] = (rcc_language_id)-1;
    } else return (rcc_relation_id)-1;
    
    
    return (rcc_relation_id)0;
}


rcc_class_id rccRegisterClass(rcc_context ctx, rcc_class *cl) {
    if (!ctx) {
	if (rcc_default_ctx) ctx = rcc_default_ctx;
	else return (rcc_class_id)-1;
    }
    if (!cl) return (rcc_class_id)-1;
    if (ctx->configuration_lock) return (rcc_class_id)-1;
    if (ctx->n_classes == ctx->max_classes) return (rcc_class_id)-1;

    ctx->configure = 1;
    
    memcpy(ctx->iclass + ctx->n_classes, cl, sizeof(rcc_class));
    ctx->iclass[ctx->n_classes].disabled = NULL;
    ctx->iclass[ctx->n_classes].additional = NULL;

    ctx->classes[ctx->n_classes] = (rcc_class_ptr)(ctx->iclass + ctx->n_classes);
    ctx->classes[++ctx->n_classes] = NULL;
    
    if (!strcasecmp(cl->name, "id3")) {
	rccRegisterDisabledCharsets(ctx, ctx->n_classes - 1, rcc_default_disabled_id3_charsets);
    } else if (!strcasecmp(cl->name, "id3v2")) {
	rccRegisterAdditionalCharsets(ctx, ctx->n_classes - 1, rcc_default_additional_id3v2_charsets);
    }

    return ctx->n_classes-1;
}

int rccRegisterDisabledCharsets(rcc_context ctx, rcc_class_id class_id, rcc_charset *charsets) {
    if (!ctx) {
	if (rcc_default_ctx) ctx = rcc_default_ctx;
	else return -1;
    }
    if (ctx->configuration_lock) return -1;
    if ((class_id == (rcc_class_id)-1)||(class_id >= ctx->n_classes)) return -1;

    ctx->iclass[class_id].disabled = charsets;
    return 0;
}

int rccRegisterAdditionalCharsets(rcc_context ctx, rcc_class_id class_id, rcc_charset *charsets) {
    if (!ctx) {
	if (rcc_default_ctx) ctx = rcc_default_ctx;
	else return -1;
    }
    if (ctx->configuration_lock) return -1;
    if ((class_id == (rcc_class_id)-1)||(class_id >= ctx->n_classes)) return -1;

    ctx->iclass[class_id].additional = charsets;
    return 0;
}

rcc_class_type rccGetClassType(rcc_context ctx, rcc_class_id class_id) {
    rcc_class_type clt;
    
    if (!ctx) {
	if (rcc_default_ctx) ctx = rcc_default_ctx;
	else return RCC_CLASS_INVALID;
    }

    if ((class_id<0)||(class_id>=ctx->n_classes)) return RCC_CLASS_INVALID;
    
    /*DS: temporary solution */
    
    clt = ctx->classes[class_id]->class_type;
    
    if ((!strcasecmp(ctx->classes[class_id]->name, "out"))&&(clt == RCC_CLASS_STANDARD))
	clt = RCC_CLASS_TRANSLATE_LOCALE;
    
    return clt;
}

const char *rccGetClassName(rcc_context ctx, rcc_class_id class_id) {
    if ((class_id<0)||(class_id>=ctx->n_classes)) return NULL;

    if (!ctx) {
	if (rcc_default_ctx) ctx = rcc_default_ctx;
	else return NULL;
    }

    return ctx->classes[class_id]->name;
}

const char *rccGetClassFullName(rcc_context ctx, rcc_class_id class_id) {
    if ((class_id<0)||(class_id>=ctx->n_classes)) return NULL;

    if (!ctx) {
	if (rcc_default_ctx) ctx = rcc_default_ctx;
	else return NULL;
    }

    return ctx->classes[class_id]->fullname;
}


int rccIsDisabledCharsetName(rcc_context ctx, rcc_class_id class_id, const char *charset) {
    unsigned int i;
    rcc_charset *charsets;

    if (!ctx) {
	if (rcc_default_ctx) ctx = rcc_default_ctx;
	else return RCC_CLASS_INVALID;
    }

    if ((!charset)||(class_id<0)||(class_id>=ctx->n_classes)) return -1;

    charsets = ctx->iclass[class_id].disabled;
    if (!charsets) return 0;
    
    for (i=0;charsets[i];i++) {
	if (!strcasecmp(charsets[i], charset)) return 1;
	else if (!strcasecmp(charsets[i], rcc_default_unicode_charsets)) {
	    if (rccIsUnicode(charset)) return 1;
	}
	else if (!strcasecmp(charsets[i], rcc_default_nonunicode_charsets)) {
	    if (!rccIsUnicode(charset)) return 1;
	}
    }
    return 0;    
}


int rccConfigure(rcc_context ctx) {
    unsigned int i;
    rcc_charset *charsets;
    const char *charset;
    rcc_language_config cfg;
    
    if (!ctx) return -1;
    if (!ctx->configure) return 0;
    
    

    cfg = rccGetCurrentConfig(ctx);
    if (!cfg) return -1;

    rccMutexLock(ctx->mutex);
    rccMutexLock(cfg->mutex);

    rccFreeIConv(ctx);
    for (i=0;i<ctx->n_classes;i++) {
	charset = rccConfigGetCurrentCharsetName(cfg, (rcc_class_id)i);
	if ((!charset)||(rccIsUTF8(charset))) continue;
	ctx->iconv_from[i] = rccIConvOpen("UTF-8", charset);
    }
    
    charsets = rccGetCurrentAutoCharsetList(ctx);
    if (charsets) {
	for (i=0;charsets[i];i++) {
	    charset = charsets[i];
	    if ((!charset)||(rccIsUTF8(charset))) continue;
	    ctx->iconv_auto[i] = rccIConvOpen("UTF-8", charset);
	}
    }
    
    ctx->configure = 0;
    
    rccMutexUnLock(cfg->mutex);
    rccMutexUnLock(ctx->mutex);
    
    return 0;
}

char *rccCreateResult(rcc_context ctx, size_t len) {
    char *res;

    if (!len) len = strlen(ctx->tmpbuffer);

    res = (char*)malloc(len+1);
    if (!res) return NULL;

    memcpy(res, ctx->tmpbuffer, len);
    res[len] = 0;
    
    return res;    
}