#include <stdio.h>
#include <stdlib.h>
#include <dlfcn.h>
#include <string.h>
#include <unistd.h> // getopt
#include <assert.h>

#define DEFUALT_PATH "./bin"
#define DEFUALT_TYPE "lalr-table"
#define DEFAULT_OUTPUT "bin/a"

#include "parts/symbol.h"
size_t total_symbols;
int (*symbol_is_terminal)(symbol s);
int (*symbol_is_input_end)(symbol s);
int (*symbol_is_valid)(symbol s);

#include "parts/grammar.h"
struct production *grammar;
size_t total_productions;

char **semantic_action_str;

#include "parts/precedence.h"
int *precedence_symbol;
int *precedence_production;

struct precedence_def{
    int flag;
    int *list;
    size_t nlist;
} *precedence_defs;
size_t nprecedence_defs;
void precedence_tables_fill();
void precedence_tables_free();

#include "parts/table.h"
struct action **table;
size_t table_states;
int (*table_fill)();
void (*table_free)();

#include "util-tables.c"


void *xdlsym(void *handle, char *sym)
{
    void *r = dlsym(handle, sym);
    if(!r) {
        fprintf(stderr, "ERROR: Symbol '%s' was not found\n", sym);
        dlclose(handle);
        exit(1);
    }
    return r;
}

#define GET_VARIABLE(var, handle)                    \
    var = *(typeof(&var))xdlsym(handle, #var)


char *modpath(char *name)
{
    static char fullpath[128];

    // TODO: search the GENERATE_PARSER_PATH env var
    char *path = DEFUALT_PATH;

    assert(snprintf(fullpath, 128, "%s/%s.so", path, name) < 128);
    return fullpath;
}

char *add_extension(char *str, char *ext)
{
    static char full[128];
    assert((strlen(str) + strlen(ext) + 1) <= 128);
    memcpy(full, str, strlen(str)+1);
    return strcat(full, ext);
}

void set_stdout(char *filename)
{
    if(!filename) filename = "/dev/tty";
    assert(freopen(filename, "w", stdout));
}

int main(int argc, char **argv)
{
    char *type = DEFUALT_TYPE;
    char *output_path = DEFAULT_OUTPUT;

    int opt;
    while((opt = getopt(argc, argv, "t:o:")) != -1) {
        switch(opt) {
        case 't': type = optarg; break;
        case 'o': output_path = optarg; break;
        default: fprintf(stderr, "ERROR: Unknown options '%c'\n", optopt);
            return 1;
        }
    }

    if(optind == argc) {
        fprintf(stderr, "ERROR: No input file\n");
        return 1;
    }

    void *table_handle = dlopen(modpath(type), RTLD_LAZY);
    if(!table_handle) { fputs(dlerror(), stderr); return 1; }
    void *def_handle = dlopen(argv[optind], RTLD_LAZY);
    if(!def_handle) { fputs(dlerror(), stderr); return 1; }

    GET_VARIABLE(table, table_handle);
    GET_VARIABLE(table_states, table_handle);
    GET_VARIABLE(table_fill, table_handle);
    GET_VARIABLE(table_free, table_handle);

    GET_VARIABLE(total_symbols, def_handle);
    GET_VARIABLE(symbol_is_terminal, def_handle);
    GET_VARIABLE(symbol_is_input_end, def_handle);
    GET_VARIABLE(symbol_is_valid, def_handle);
    GET_VARIABLE(grammar, def_handle);
    GET_VARIABLE(total_productions, def_handle);
    GET_VARIABLE(semantic_action_str, def_handle);
    GET_VARIABLE(precedence_defs, def_handle);
    GET_VARIABLE(nprecedence_defs, def_handle);

    precedence_tables_fill();
    util_tables_fill();

    int r = 0;
    if((r = table_fill())) {
        fprintf(stderr, "ERROR: Table couldn't be generated\n");
        goto cleanup;
    }

    set_stdout(add_extension(output_path, ".c"));
    printf("size_t total_symbols = %zu;\n", total_symbols);
    printf("IMPLEMENT_FUNCPTR(int, symbol_is_valid, (symbol s)) {return s < total_symbols;}\n");

    printf("struct production _grammar[] = {\n");
    grammar_print_cstyle();
    printf("};\n");

    printf("struct production *grammar = _grammar;");
    printf("size_t total_productions = %zu;\n", total_productions);

    printf("struct action **table = (struct action *([])){\n");
    table_print_cstyle();
    printf("};\n");
    printf("size_t table_states = %zu;\n", table_states);

    printf("int *precedence_symbol = (int[]){");
    for(size_t i = 0; i < total_symbols; i++) printf("%d, ", precedence_symbol[i]);
    printf("};\n");
    printf("int *precedence_production = (int[]){");
    for(size_t i = 0; i < total_productions; i++) printf("%d, ", precedence_production[i]);
    printf("};\n");

    for(size_t i = 0; i < total_productions; i++) {
        printf("#define A(n) (*(stack_head-3*%zu+3*n-1))\n", grammar[i].nRHS-1);
        printf("int __prod%zu_action(int *stack_head)\n", i);
        printf("{ int v;\n");
        printf(semantic_action_str[i]);
        printf("return v; }\n");
        printf("#undef A\n");
    }

    printf("typedef int (*semantic_action_fn)(int *stack_head);\n");

    printf("semantic_action_fn *semantic_actions = (semantic_action_fn[]){\n");
    for(size_t i = 0; i < total_productions; i++)
        printf("__prod%zu_action, ", i);
    printf("};");
    set_stdout(NULL);

cleanup:
    table_free();
    precedence_tables_free();
    util_tables_free();

    dlclose(table_handle);
    dlclose(def_handle);
    return r;
}

void precedence_tables_fill()
{
    precedence_symbol = calloc(total_symbols, sizeof(*precedence_symbol));
    precedence_production = calloc(total_productions, sizeof(*precedence_production));

    for(size_t i = 0; i < nprecedence_defs; i++)
        for(size_t j = 0; j < precedence_defs[i].nlist; j++)
            if(precedence_defs[i].flag >= 0)
                precedence_symbol[precedence_defs[i].list[j]] = PRECEDENCE_SET(precedence_defs[i].flag, i+1);
            else
                precedence_production[precedence_defs[i].list[j]] = PRECEDENCE_SET(~precedence_defs[i].flag, i+1);

    for(size_t i = 0; i < total_productions; i++) {
        if(precedence_production[i]) continue;

        for(size_t j = 0; j < grammar[i].nRHS; j++)
            if(precedence_symbol[grammar[i].RHS[j]]) {
                precedence_production[i] = precedence_symbol[grammar[i].RHS[j]];
                break;
            }
    }
}
void precedence_tables_free()
{
    free(precedence_symbol);
    free(precedence_production);
}