#include "cache.h"

#include "string-list.h"

#include "mailmap.h"

#include "object-store.h"

#define DEBUG_MAILMAP 0

#if DEBUG_MAILMAP

#define debug_mm(...) fprintf(stderr, __VA_ARGS__)

#define debug_str(X) ((X) ? (X) : "(none)")

#else

static inline void debug_mm(const char *format, ...) {}

static inline const char *debug_str(const char *s) { return s; }

#endif

const char *git_mailmap_file;

const char *git_mailmap_blob;

struct mailmap_info {

	char *name;

	char *email;

};

struct mailmap_entry {

	/* name and email for the simple mail-only case */

	char *name;

	char *email;

	/* name and email for the complex mail and name matching case */

	struct string_list namemap;

};

static void free_mailmap_info(void *p, const char *s)

{

	struct mailmap_info *mi = (struct mailmap_info *)p;

	debug_mm("mailmap: -- complex: '%s' -> '%s' <%s>\n",

		 s, debug_str(mi->name), debug_str(mi->email));

	free(mi->name);

	free(mi->email);

}

static void free_mailmap_entry(void *p, const char *s)

{

	struct mailmap_entry *me = (struct mailmap_entry *)p;

	debug_mm("mailmap: removing entries for <%s>, with %d sub-entries\n",

		 s, me->namemap.nr);

	debug_mm("mailmap: - simple: '%s' <%s>\n",

		 debug_str(me->name), debug_str(me->email));

	free(me->name);

	free(me->email);

	me->namemap.strdup_strings = 1;

	string_list_clear_func(&me->namemap, free_mailmap_info);

}

/*

 * On some systems (e.g. MinGW 4.0), string.h has _only_ inline

 * definition of strcasecmp and no non-inline implementation is

 * supplied anywhere, which is, eh, "unusual"; we cannot take an

 * address of such a function to store it in namemap.cmp.  This is

 * here as a workaround---do not assign strcasecmp directly to

 * namemap.cmp until we know no systems that matter have such an

 * "unusual" string.h.

 */

static int namemap_cmp(const char *a, const char *b)

{

	return strcasecmp(a, b);

}

static void add_mapping(struct string_list *map,

			char *new_name, char *new_email,

			char *old_name, char *old_email)

{

	struct mailmap_entry *me;

	struct string_list_item *item;

	if (old_email == NULL) {

		old_email = new_email;

		new_email = NULL;

	}

	item = string_list_insert(map, old_email);

	if (item->util) {

		me = (struct mailmap_entry *)item->util;

	} else {

		me = xcalloc(1, sizeof(struct mailmap_entry));

		me->namemap.strdup_strings = 1;

		me->namemap.cmp = namemap_cmp;

		item->util = me;

	}

	if (old_name == NULL) {

		debug_mm("mailmap: adding (simple) entry for '%s'\n", old_email);

		/* Replace current name and new email for simple entry */

		if (new_name) {

			free(me->name);

			me->name = xstrdup(new_name);

		}

		if (new_email) {

			free(me->email);

			me->email = xstrdup(new_email);

		}

	} else {

		struct mailmap_info *mi = xcalloc(1, sizeof(struct mailmap_info));

		debug_mm("mailmap: adding (complex) entry for '%s'\n", old_email);

		mi->name = xstrdup_or_null(new_name);

		mi->email = xstrdup_or_null(new_email);

		string_list_insert(&me->namemap, old_name)->util = mi;

	}

	debug_mm("mailmap:  '%s' <%s> -> '%s' <%s>\n",

		 debug_str(old_name), old_email,

		 debug_str(new_name), debug_str(new_email));

}

static char *parse_name_and_email(char *buffer, char **name,

				  char **email, int allow_empty_email)

{

	char *left, *right, *nstart, *nend;

	*name = *email = NULL;

	if ((left = strchr(buffer, '<')) == NULL)

		return NULL;

	if ((right = strchr(left+1, '>')) == NULL)

		return NULL;

	if (!allow_empty_email && (left+1 == right))

		return NULL;

	/* remove whitespace from beginning and end of name */

	nstart = buffer;

	while (isspace(*nstart) && nstart < left)

		++nstart;

	nend = left-1;

	while (nend > nstart && isspace(*nend))

		--nend;

	*name = (nstart <= nend ? nstart : NULL);

	*email = left+1;

	*(nend+1) = '\0';

	*right++ = '\0';

	return (*right == '\0' ? NULL : right);

}

static void read_mailmap_line(struct string_list *map, char *buffer,

			      char **repo_abbrev)

{

	char *name1 = NULL, *email1 = NULL, *name2 = NULL, *email2 = NULL;

	if (buffer[0] == '#') {

		static const char abbrev[] = "# repo-abbrev:";

		int abblen = sizeof(abbrev) - 1;

		int len = strlen(buffer);

		if (!repo_abbrev)

			return;

		if (len && buffer[len - 1] == '\n')

			buffer[--len] = 0;

		if (!strncmp(buffer, abbrev, abblen)) {

			char *cp;

			free(*repo_abbrev);

			for (cp = buffer + abblen; isspace(*cp); cp++)

				; /* nothing */

			*repo_abbrev = xstrdup(cp);

		}

		return;

	}

	if ((name2 = parse_name_and_email(buffer, &name1, &email1, 0)) != NULL)

		parse_name_and_email(name2, &name2, &email2, 1);

	if (email1)

		add_mapping(map, name1, email1, name2, email2);

}

static int read_mailmap_file(struct string_list *map, const char *filename,

			     char **repo_abbrev)

{

	char buffer[1024];

	FILE *f;

	if (!filename)

		return 0;

	f = fopen(filename, "r");

	if (!f) {

		if (errno == ENOENT)

			return 0;

		return error_errno("unable to open mailmap at %s", filename);

	}

	while (fgets(buffer, sizeof(buffer), f) != NULL)

		read_mailmap_line(map, buffer, repo_abbrev);

	fclose(f);

	return 0;

}

static void read_mailmap_string(struct string_list *map, char *buf,

				char **repo_abbrev)

{

	while (*buf) {

		char *end = strchrnul(buf, '\n');

		if (*end)

			*end++ = '\0';

		read_mailmap_line(map, buf, repo_abbrev);

		buf = end;

	}

}

static int read_mailmap_blob(struct string_list *map,

			     const char *name,

			     char **repo_abbrev)

{

	struct object_id oid;

	char *buf;

	unsigned long size;

	enum object_type type;

	if (!name)

		return 0;

	if (get_oid(name, &oid) < 0)

		return 0;

	buf = read_object_file(&oid, &type, &size);

	if (!buf)

		return error("unable to read mailmap object at %s", name);

	if (type != OBJ_BLOB)

		return error("mailmap is not a blob: %s", name);

	read_mailmap_string(map, buf, repo_abbrev);

	free(buf);

	return 0;

}

int read_mailmap(struct string_list *map, char **repo_abbrev)

{

	int err = 0;

	map->strdup_strings = 1;

	map->cmp = namemap_cmp;

	if (!git_mailmap_blob && is_bare_repository())

		git_mailmap_blob = "HEAD:.mailmap";

	err |= read_mailmap_file(map, ".mailmap", repo_abbrev);

	if (startup_info->have_repository)

		err |= read_mailmap_blob(map, git_mailmap_blob, repo_abbrev);

	err |= read_mailmap_file(map, git_mailmap_file, repo_abbrev);

	return err;

}

void clear_mailmap(struct string_list *map)

{

	debug_mm("mailmap: clearing %d entries...\n", map->nr);

	map->strdup_strings = 1;

	string_list_clear_func(map, free_mailmap_entry);

	debug_mm("mailmap: cleared\n");

}

/*

 * Look for an entry in map that match string[0:len]; string[len]

 * does not have to be NUL (but it could be).

 */

static struct string_list_item *lookup_prefix(struct string_list *map,

					      const char *string, size_t len)

{

	int i = string_list_find_insert_index(map, string, 1);

	if (i < 0) {

		/* exact match */

		i = -1 - i;

		if (!string[len])

			return &map->items[i];

		/*

		 * that map entry matches exactly to the string, including

		 * the cruft at the end beyond "len".  That is not a match

		 * with string[0:len] that we are looking for.

		 */

	} else if (!string[len]) {

		/*

		 * asked with the whole string, and got nothing.  No

		 * matching entry can exist in the map.

		 */

		return NULL;

	}

	/*

	 * i is at the exact match to an overlong key, or location the

	 * overlong key would be inserted, which must come after the

	 * real location of the key if one exists.

	 */

	while (0 <= --i && i < map->nr) {

		int cmp = strncasecmp(map->items[i].string, string, len);

		if (cmp < 0)

			/*

			 * "i" points at a key definitely below the prefix;

			 * the map does not have string[0:len] in it.

			 */

			break;

		else if (!cmp && !map->items[i].string[len])

			/* found it */

			return &map->items[i];

		/*

		 * otherwise, the string at "i" may be string[0:len]

		 * followed by a string that sorts later than string[len:];

		 * keep trying.

		 */

	}

	return NULL;

}

int map_user(struct string_list *map,

	     const char **email, size_t *emaillen,

	     const char **name, size_t *namelen)

{

	struct string_list_item *item;

	struct mailmap_entry *me;

	debug_mm("map_user: map '%.*s' <%.*s>\n",

		 (int)*namelen, debug_str(*name),

		 (int)*emaillen, debug_str(*email));

	item = lookup_prefix(map, *email, *emaillen);

	if (item != NULL) {

		me = (struct mailmap_entry *)item->util;

		if (me->namemap.nr) {

			/*

			 * The item has multiple items, so we'll look up on

			 * name too. If the name is not found, we choose the

			 * simple entry.

			 */

			struct string_list_item *subitem;

			subitem = lookup_prefix(&me->namemap, *name, *namelen);

			if (subitem)

				item = subitem;

		}

	}

	if (item != NULL) {

		struct mailmap_info *mi = (struct mailmap_info *)item->util;

		if (mi->name == NULL && mi->email == NULL) {

			debug_mm("map_user:  -- (no simple mapping)\n");

			return 0;

		}

		if (mi->email) {

				*email = mi->email;

				*emaillen = strlen(*email);

		}

		if (mi->name) {

				*name = mi->name;

				*namelen = strlen(*name);

		}

		debug_mm("map_user:  to '%.*s' <%.*s>\n",

			 (int)*namelen, debug_str(*name),

			 (int)*emaillen, debug_str(*email));

		return 1;

	}

	debug_mm("map_user:  --\n");

	return 0;

}