#include "cache.h"
#include "userdiff.h"
#include "cache.h"
#include "attr.h"

static struct userdiff_driver *drivers;
static int ndrivers;
static int drivers_alloc;

#define PATTERNS(name, pattern, word_regex)                     \
        { name, NULL, -1, { pattern, REG_EXTENDED },            \
          word_regex "|[^[:space:]]|[\xc0-\xff][\x80-\xbf]+" }
#define IPATTERN(name, pattern, word_regex)                     \
        { name, NULL, -1, { pattern, REG_EXTENDED | REG_ICASE }, \
          word_regex "|[^[:space:]]|[\xc0-\xff][\x80-\xbf]+" }
static struct userdiff_driver builtin_drivers[] = {
IPATTERN("fortran",
         "!^([C*]|[ \t]*!)\n"
         "!^[ \t]*MODULE[ \t]+PROCEDURE[ \t]\n"
         "^[ \t]*((END[ \t]+)?(PROGRAM|MODULE|BLOCK[ \t]+DATA"
                "|([^'\" \t]+[ \t]+)*(SUBROUTINE|FUNCTION))[ \t]+[A-Z].*)$",
         /* -- */
         "[a-zA-Z][a-zA-Z0-9_]*"
         "|\\.([Ee][Qq]|[Nn][Ee]|[Gg][TtEe]|[Ll][TtEe]|[Tt][Rr][Uu][Ee]|[Ff][Aa][Ll][Ss][Ee]|[Aa][Nn][Dd]|[Oo][Rr]|[Nn]?[Ee][Qq][Vv]|[Nn][Oo][Tt])\\."
         /* numbers and format statements like 2E14.4, or ES12.6, 9X.
          * Don't worry about format statements without leading digits since
          * they would have been matched above as a variable anyway. */
         "|[-+]?[0-9.]+([AaIiDdEeFfLlTtXx][Ss]?[-+]?[0-9.]*)?(_[a-zA-Z0-9][a-zA-Z0-9_]*)?"
         "|//|\\*\\*|::|[/<>=]="),
PATTERNS("html", "^[ \t]*(<[Hh][1-6][ \t].*>.*)$",
         "[^<>= \t]+"),
PATTERNS("java",
         "!^[ \t]*(catch|do|for|if|instanceof|new|return|switch|throw|while)\n"
         "^[ \t]*(([A-Za-z_][A-Za-z_0-9]*[ \t]+)+[A-Za-z_][A-Za-z_0-9]*[ \t]*\\([^;]*)$",
         /* -- */
         "[a-zA-Z_][a-zA-Z0-9_]*"
         "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
         "|[-+*/<>%&^|=!]="
         "|--|\\+\\+|<<=?|>>>?=?|&&|\\|\\|"),
PATTERNS("objc",
         /* Negate C statements that can look like functions */
         "!^[ \t]*(do|for|if|else|return|switch|while)\n"
         /* Objective-C methods */
         "^[ \t]*([-+][ \t]*\\([ \t]*[A-Za-z_][A-Za-z_0-9* \t]*\\)[ \t]*[A-Za-z_].*)$\n"
         /* C functions */
         "^[ \t]*(([A-Za-z_][A-Za-z_0-9]*[ \t]+)+[A-Za-z_][A-Za-z_0-9]*[ \t]*\\([^;]*)$\n"
         /* Objective-C class/protocol definitions */
         "^(@(implementation|interface|protocol)[ \t].*)$",
         /* -- */
         "[a-zA-Z_][a-zA-Z0-9_]*"
         "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
         "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"),
PATTERNS("pascal",
         "^(((class[ \t]+)?(procedure|function)|constructor|destructor|interface|"
                "implementation|initialization|finalization)[ \t]*.*)$"
         "\n"
         "^(.*=[ \t]*(class|record).*)$",
         /* -- */
         "[a-zA-Z_][a-zA-Z0-9_]*"
         "|[-+0-9.e]+|0[xXbB]?[0-9a-fA-F]+"
         "|<>|<=|>=|:=|\\.\\."),
PATTERNS("perl",
         "^[ \t]*package .*;\n"
         "^[ \t]*sub .* \\{\n"
         "^[A-Z]+ \\{\n"        /* BEGIN, END, ... */
         "^=head[0-9] ",        /* POD */
         /* -- */
         "[[:alpha:]_'][[:alnum:]_']*"
         "|0[xb]?[0-9a-fA-F_]*"
         /* taking care not to interpret 3..5 as (3.)(.5) */
         "|[0-9a-fA-F_]+(\\.[0-9a-fA-F_]+)?([eE][-+]?[0-9_]+)?"
         "|=>|-[rwxoRWXOezsfdlpSugkbctTBMAC>]|~~|::"
         "|&&=|\\|\\|=|//=|\\*\\*="
         "|&&|\\|\\||//|\\+\\+|--|\\*\\*|\\.\\.\\.?"
         "|[-+*/%.^&<>=!|]="
         "|=~|!~"
         "|<<|<>|<=>|>>"),
PATTERNS("php",
         "^[\t ]*(((public|protected|private|static)[\t ]+)*function.*)$\n"
         "^[\t ]*(class.*)$",
         /* -- */
         "[a-zA-Z_][a-zA-Z0-9_]*"
         "|[-+0-9.e]+|0[xXbB]?[0-9a-fA-F]+"
         "|[-+*/<>%&^|=!.]=|--|\\+\\+|<<=?|>>=?|===|&&|\\|\\||::|->"),
PATTERNS("python", "^[ \t]*((class|def)[ \t].*)$",
         /* -- */
         "[a-zA-Z_][a-zA-Z0-9_]*"
         "|[-+0-9.e]+[jJlL]?|0[xX]?[0-9a-fA-F]+[lL]?"
         "|[-+*/<>%&^|=!]=|//=?|<<=?|>>=?|\\*\\*=?"),
         /* -- */
PATTERNS("ruby", "^[ \t]*((class|module|def)[ \t].*)$",
         /* -- */
         "(@|@@|\\$)?[a-zA-Z_][a-zA-Z0-9_]*"
         "|[-+0-9.e]+|0[xXbB]?[0-9a-fA-F]+|\\?(\\\\C-)?(\\\\M-)?."
         "|//=?|[-+*/<>%&^|=!]=|<<=?|>>=?|===|\\.{1,3}|::|[!=]~"),
PATTERNS("bibtex", "(@[a-zA-Z]{1,}[ \t]*\\{{0,1}[ \t]*[^ \t\"@',\\#}{~%]*).*$",
         "[={}\"]|[^={}\" \t]+"),
PATTERNS("tex", "^(\\\\((sub)*section|chapter|part)\\*{0,1}\\{.*)$",
         "\\\\[a-zA-Z@]+|\\\\.|[a-zA-Z0-9\x80-\xff]+"),
PATTERNS("cpp",
         /* Jump targets or access declarations */
         "!^[ \t]*[A-Za-z_][A-Za-z_0-9]*:.*$\n"
         /* C/++ functions/methods at top level */
         "^([A-Za-z_][A-Za-z_0-9]*([ \t]+[A-Za-z_][A-Za-z_0-9]*([ \t]*::[ \t]*[^[:space:]]+)?){1,}[ \t]*\\([^;]*)$\n"
         /* compound type at top level */
         "^((struct|class|enum)[^;]*)$",
         /* -- */
         "[a-zA-Z_][a-zA-Z0-9_]*"
         "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
         "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"),
PATTERNS("csharp",
         /* Keywords */
         "!^[ \t]*(do|while|for|if|else|instanceof|new|return|switch|case|throw|catch|using)\n"
         /* Methods and constructors */
         "^[ \t]*(((static|public|internal|private|protected|new|virtual|sealed|override|unsafe)[ \t]+)*[][<>@.~_[:alnum:]]+[ \t]+[<>@._[:alnum:]]+[ \t]*\\(.*\\))[ \t]*$\n"
         /* Properties */
         "^[ \t]*(((static|public|internal|private|protected|new|virtual|sealed|override|unsafe)[ \t]+)*[][<>@.~_[:alnum:]]+[ \t]+[@._[:alnum:]]+)[ \t]*$\n"
         /* Type definitions */
         "^[ \t]*(((static|public|internal|private|protected|new|unsafe|sealed|abstract|partial)[ \t]+)*(class|enum|interface|struct)[ \t]+.*)$\n"
         /* Namespace */
         "^[ \t]*(namespace[ \t]+.*)$",
         /* -- */
         "[a-zA-Z_][a-zA-Z0-9_]*"
         "|[-+0-9.e]+[fFlL]?|0[xXbB]?[0-9a-fA-F]+[lL]?"
         "|[-+*/<>%&^|=!]=|--|\\+\\+|<<=?|>>=?|&&|\\|\\||::|->"),
{ "default", NULL, -1, { NULL, 0 } },
};
#undef PATTERNS
#undef IPATTERN

static struct userdiff_driver driver_true = {
        "diff=true",
        NULL,
        0,
        { NULL, 0 }
};

static struct userdiff_driver driver_false = {
        "!diff",
        NULL,
        1,
        { NULL, 0 }
};

static struct userdiff_driver *userdiff_find_by_namelen(const char *k, int len)
{
        int i;
        for (i = 0; i < ndrivers; i++) {
                struct userdiff_driver *drv = drivers + i;
                if (!strncmp(drv->name, k, len) && !drv->name[len])
                        return drv;
        }
        for (i = 0; i < ARRAY_SIZE(builtin_drivers); i++) {
                struct userdiff_driver *drv = builtin_drivers + i;
                if (!strncmp(drv->name, k, len) && !drv->name[len])
                        return drv;
        }
        return NULL;
}

static struct userdiff_driver *parse_driver(const char *var,
                const char *value, const char *type)
{
        struct userdiff_driver *drv;
        const char *dot;
        const char *name;
        int namelen;

        if (prefixcmp(var, "diff."))
                return NULL;
        dot = strrchr(var, '.');
        if (dot == var + 4)
                return NULL;
        if (strcmp(type, dot+1))
                return NULL;

        name = var + 5;
        namelen = dot - name;
        drv = userdiff_find_by_namelen(name, namelen);
        if (!drv) {
                ALLOC_GROW(drivers, ndrivers+1, drivers_alloc);
                drv = &drivers[ndrivers++];
                memset(drv, 0, sizeof(*drv));
                drv->name = xmemdupz(name, namelen);
                drv->binary = -1;
        }
        return drv;
}

static int parse_funcname(struct userdiff_funcname *f, const char *k,
                const char *v, int cflags)
{
        if (git_config_string(&f->pattern, k, v) < 0)
                return -1;
        f->cflags = cflags;
        return 1;
}

static int parse_string(const char **d, const char *k, const char *v)
{
        if (git_config_string(d, k, v) < 0)
                return -1;
        return 1;
}

static int parse_tristate(int *b, const char *k, const char *v)
{
        if (v && !strcasecmp(v, "auto"))
                *b = -1;
        else
                *b = git_config_bool(k, v);
        return 1;
}

static int parse_bool(int *b, const char *k, const char *v)
{
        *b = git_config_bool(k, v);
        return 1;
}

int userdiff_config(const char *k, const char *v)
{
        struct userdiff_driver *drv;

        if ((drv = parse_driver(k, v, "funcname")))
                return parse_funcname(&drv->funcname, k, v, 0);
        if ((drv = parse_driver(k, v, "xfuncname")))
                return parse_funcname(&drv->funcname, k, v, REG_EXTENDED);
        if ((drv = parse_driver(k, v, "binary")))
                return parse_tristate(&drv->binary, k, v);
        if ((drv = parse_driver(k, v, "command")))
                return parse_string(&drv->external, k, v);
        if ((drv = parse_driver(k, v, "textconv")))
                return parse_string(&drv->textconv, k, v);
        if ((drv = parse_driver(k, v, "cachetextconv")))
                return parse_bool(&drv->textconv_want_cache, k, v);
        if ((drv = parse_driver(k, v, "wordregex")))
                return parse_string(&drv->word_regex, k, v);

        return 0;
}

struct userdiff_driver *userdiff_find_by_name(const char *name) {
        int len = strlen(name);
        return userdiff_find_by_namelen(name, len);
}

struct userdiff_driver *userdiff_find_by_path(const char *path)
{
        static struct git_attr *attr;
        struct git_attr_check check;

        if (!attr)
                attr = git_attr("diff");
        check.attr = attr;

        if (!path)
                return NULL;
        if (git_checkattr(path, 1, &check))
                return NULL;

        if (ATTR_TRUE(check.value))
                return &driver_true;
        if (ATTR_FALSE(check.value))
                return &driver_false;
        if (ATTR_UNSET(check.value))
                return NULL;
        return userdiff_find_by_name(check.value);
}