/** \ingroup rpmdep
 * \file lib/rpmal.c
 */

#include "system.h"


#include <rpm/rpmds.h>
#include <rpm/rpmte.h>
#include <rpm/rpmfi.h>

#include "lib/rpmal.h"
#include "lib/misc.h"

#include "debug.h"

typedef struct availablePackage_s * availablePackage;
typedef int rpmalNum;

/** \ingroup rpmdep
 * Info about a single package to be installed.
 */
struct availablePackage_s {
    rpmte p;                    /*!< transaction member */
    rpmds provides;		/*!< Provides: dependencies. */
    rpmfi fi;			/*!< File info set. */
};

typedef struct availableIndexEntry_s *	availableIndexEntry;

/** \ingroup rpmdep
 * A single available item (e.g. a Provides: dependency).
 */
struct availableIndexEntry_s {
    rpmalNum pkgNum;	        /*!< Containing package index. */
    unsigned int entryIx;	/*!< Dependency index. */
};

struct fileNameEntry_s {
    const char * dirName;
    const char * baseName;
};


/** \ingroup rpmdep
 * A file to be installed/removed.
 */
typedef struct fileIndexEntry_s * fileIndex;

struct fileIndexEntry_s {
    rpmalNum pkgNum;		/*!< Containing package index. */
    unsigned int entryIx;
};

#undef HASHTYPE
#undef HTKEYTYPE
#undef HTDATATYPE
#define HASHTYPE rpmalProvidesHash
#define HTKEYTYPE const char *
#define HTDATATYPE struct availableIndexEntry_s
#include "lib/rpmhash.H"
#include "lib/rpmhash.C"

#undef HASHTYPE
#undef HTKEYTYPE
#undef HTDATATYPE
#define HASHTYPE rpmalFileHash
#define HTKEYTYPE struct fileNameEntry_s
#define HTDATATYPE struct fileIndexEntry_s
#include "lib/rpmhash.H"
#include "lib/rpmhash.C"



/** \ingroup rpmdep
 * Set of available packages, items, and directories.
 */
struct rpmal_s {
    availablePackage list;	/*!< Set of packages. */
    rpmalProvidesHash providesHash;
    rpmalFileHash fileHash;
    int delta;			/*!< Delta for pkg list reallocation. */
    int size;			/*!< No. of pkgs in list. */
    int alloced;		/*!< No. of pkgs allocated for list. */
    rpm_color_t tscolor;	/*!< Transaction color. */
    rpm_color_t prefcolor;	/*!< Transaction preferred color. */
};

/**
 * Destroy available item index.
 * @param al		available list
 */
static void rpmalFreeIndex(rpmal al)
{
    al->providesHash = rpmalProvidesHashFree(al->providesHash);
    al->fileHash = rpmalFileHashFree(al->fileHash);
}

rpmal rpmalCreate(int delta, rpm_color_t tscolor, rpm_color_t prefcolor)
{
    rpmal al = xcalloc(1, sizeof(*al));

    al->delta = delta;
    al->size = 0;
    al->alloced = al->delta;
    al->list = xmalloc(sizeof(*al->list) * al->alloced);;

    al->providesHash = NULL;
    al->fileHash = NULL;
    al->tscolor = tscolor;
    al->prefcolor = prefcolor;

    return al;
}

rpmal rpmalFree(rpmal al)
{
    availablePackage alp;
    int i;

    if (al == NULL)
	return NULL;

    if ((alp = al->list) != NULL)
    for (i = 0; i < al->size; i++, alp++) {
	alp->provides = rpmdsFree(alp->provides);
	alp->fi = rpmfiFree(alp->fi);
    }
    al->list = _free(al->list);
    al->alloced = 0;

    rpmalFreeIndex(al);
    al = _free(al);
    return NULL;
}

static unsigned int fileHash(struct fileNameEntry_s file){
    return hashFunctionString(file.dirName) ^ hashFunctionString(file.baseName);
}

static int fileCompare(struct fileNameEntry_s one, struct fileNameEntry_s two) {
    int rc = 0;
    rc = strcmp(one.dirName, two.dirName);
    if (!rc)
	rc = strcmp(one.baseName, two.baseName);
    return rc;
}

void rpmalDel(rpmal al, rpmte p)
{
    availablePackage alp;
    rpmalNum pkgNum;

    if (al == NULL || al->list == NULL)
	return;		/* XXX can't happen */

    // XXX use a search for self provide
    for (pkgNum=0; pkgNum<al->size; pkgNum++) {
	if (al->list[pkgNum].p == p) {
	    break;
	}
    }
    if (pkgNum == al->size ) return; // Not found!

    alp = al->list + pkgNum;
    // do not actually delete, just set p to NULL
    // and later filter that out of the results
    alp->p = NULL;
}

static void rpmalAddFiles(rpmal al, rpmalNum pkgNum, rpmfi fi){
    struct fileNameEntry_s fileName;
    struct fileIndexEntry_s fileEntry;
    int i;
    rpm_color_t ficolor;

    fileEntry.pkgNum = pkgNum;

    fi = rpmfiInit(fi, 0);
    while ((i = rpmfiNext(fi)) >= 0) {
	/* Ignore colored provides not in our rainbow. */
        ficolor = rpmfiFColor(fi);
        if (al->tscolor && ficolor && !(al->tscolor & ficolor))
            continue;

	fileName.dirName = rpmfiDN(fi);
	fileName.baseName = rpmfiBN(fi);

	fileEntry.entryIx = i;

	rpmalFileHashAddEntry(al->fileHash, fileName, fileEntry);
    }
}

static void rpmalAddProvides(rpmal al, rpmalNum pkgNum, rpmds provides){
    struct availableIndexEntry_s indexEntry;
    rpm_color_t dscolor;

    indexEntry.pkgNum = pkgNum;

    if (rpmdsInit(provides) != NULL)
    while (rpmdsNext(provides) >= 0) {
        /* Ignore colored provides not in our rainbow. */
        dscolor = rpmdsColor(provides);
        if (al->tscolor && dscolor && !(al->tscolor & dscolor))
            continue;

	indexEntry.entryIx = rpmdsIx(provides);
	rpmalProvidesHashAddEntry(al->providesHash, rpmdsN(provides), indexEntry);
    }
}

void rpmalAdd(rpmal al, rpmte p)
{
    rpmalNum pkgNum;
    availablePackage alp;

    if (al->size == al->alloced) {
	al->alloced += al->delta;
	al->list = xrealloc(al->list, sizeof(*al->list) * al->alloced);
    }
    pkgNum = al->size++;

    alp = al->list + pkgNum;

    alp->p = p;

    alp->provides = rpmdsLink(rpmteDS(p, RPMTAG_PROVIDENAME));
    alp->fi = rpmfiLink(rpmteFI(p));

    if (al->providesHash != NULL) { // index is already created
	rpmalAddProvides(al, pkgNum, alp->provides);
	rpmalAddFiles(al, pkgNum, alp->fi);
    }

    assert(((rpmalNum)(alp - al->list)) == pkgNum);
}

static void rpmalMakeIndex(rpmal al)
{
    availablePackage alp;
    int i;
    int providesCnt = 0;
    int fileCnt = 0;

    if (al == NULL || al->list == NULL) return;
    if (al->providesHash != NULL || al->fileHash != NULL)
	return;
    for (i = 0; i < al->size; i++) {
	alp = al->list + i;
	if (alp->provides != NULL)
	    providesCnt += rpmdsCount(alp->provides);
	if (alp->fi != NULL)
	    fileCnt += rpmfiFC(alp->fi);
    }

    al->providesHash = rpmalProvidesHashCreate(providesCnt/4+128, hashFunctionString,
					       strcmp, NULL, NULL);
    al->fileHash = rpmalFileHashCreate(fileCnt/4+128, fileHash, fileCompare,
				       NULL, NULL);

    for (i = 0; i < al->size; i++) {
	alp = al->list + i;
	rpmalAddProvides(al, i, alp->provides);
	rpmalAddFiles(al, i, alp->fi);
    }
}

static rpmte * rpmalAllFileSatisfiesDepend(const rpmal al, const rpmds ds)
{
    const char *fileName = rpmdsN(ds);
    const char *slash; 
    rpmte * ret = NULL;

    if (al == NULL || fileName == NULL || *fileName != '/')
	return NULL;

    /* Split path into dirname and basename components for lookup */
    if ((slash = strrchr(fileName, '/')) != NULL) {
	fileIndex result;
	int resultCnt = 0;
	size_t bnStart = (slash - fileName) + 1;
	char dirName[bnStart + 1];
	struct fileNameEntry_s fne = {
	    .baseName = fileName + bnStart,
	    .dirName = dirName,
	};
	strncpy(dirName, fileName, bnStart);
	dirName[bnStart] = '\0';

	rpmalFileHashGetEntry(al->fileHash, fne, &result, &resultCnt, NULL);

	if (resultCnt > 0) {
	    int i, found;
	    ret = xmalloc((resultCnt+1) * sizeof(*ret));

	    for (found = i = 0; i < resultCnt; i++) {
		availablePackage alp = al->list + result[i].pkgNum;
		if (alp->p == NULL) // deleted
		    continue;

		rpmdsNotify(ds, "(added files)", 0);

		ret[found] = alp->p;
		found++;
	    }
	    ret[found] = NULL;
	}
    }

    return ret;
}

static rpmte * rpmalAllSatisfiesDepend(const rpmal al, const rpmds ds)
{
    rpmte * ret = NULL;
    int i, found;
    const char * name;
    availableIndexEntry result;
    int resultCnt;

    availablePackage alp;
    int rc;

    if (al == NULL || ds == NULL || (name = rpmdsN(ds)) == NULL)
	return ret;

    if (al->providesHash == NULL && al->fileHash == NULL)
	rpmalMakeIndex(al);

    if (*name == '/') {
	/* First, look for files "contained" in package ... */
	ret = rpmalAllFileSatisfiesDepend(al, ds);
	if (ret != NULL && *ret != NULL)
	    return ret;
	/* ... then, look for files "provided" by package. */
	ret = _free(ret);
    }

    rpmalProvidesHashGetEntry(al->providesHash, name, &result,
			      &resultCnt, NULL);

    if (resultCnt==0) return NULL;

    ret = xmalloc((resultCnt+1) * sizeof(*ret));

    for (found=i=0; i<resultCnt; i++) {
	alp = al->list + result[i].pkgNum;
	if (alp->p == NULL) // deleted
	    continue;
	(void) rpmdsSetIx(alp->provides, result[i].entryIx);
	rc = 0;
	if (rpmdsIx(alp->provides) >= 0)
	    rc = rpmdsCompare(alp->provides, ds);

	if (rc) {
	    rpmdsNotify(ds, "(added provide)", 0);
	    ret[found] = alp->p;
	    found++;
	}
    }
    ret[found] = NULL;

    return ret;
}

rpmte
rpmalSatisfiesDepend(const rpmal al, const rpmds ds)
{
    rpmte *providers = rpmalAllSatisfiesDepend(al, ds);
    rpmte best = NULL;

    if (providers) {
	if (al->tscolor) {
	    /*
	     * For colored dependencies, try to find a matching provider.
	     * Otherwise prefer provider of ts preferred color.
	     */
	    rpm_color_t dscolor = rpmdsColor(ds);
	    for (rpmte *p = providers; *p; p++) {
		rpm_color_t tecolor = rpmteColor(*p);
		if (dscolor) {
		    if (dscolor == tecolor) best = *p;
		} else if (al->prefcolor) {
		    if (al->prefcolor == tecolor) best = *p;
		}
		if (best) break;
	    }
	}
	/* if not decided by now, just pick first match */
	if (!best) best = providers[0];
	free(providers);
    }
    return best;
}