#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>

#include "bytecode.h"
#include "format.h"
#include "io.h"
#include "lex.h"

#define ELF_HEADER_SIZE 0xb0

enum map_type {
    MAP_LEFT_TIMES,
    MAP_RIGHT_TIMES,
    MAP_LEFT_PLUS,
    MAP_RIGHT_PLUS,
};

static enum map_type maps[16];
static size_t mapi = 0;

static char* label_names[2048];
static symbol label_symbols[2048];
static size_t labeli = 0;

enum map_type pop(void) {
    if (mapi <= 0) {
        fprintf(stderr, "unmatched }\n");
        exit(1);
    }

    return maps[--mapi];
}

void push(enum map_type type) {
    if (mapi >= 16) {
        fprintf(stderr, "out of maps\n");
        exit(1);
    }

    maps[mapi++] = type;
}

symbol lookup_label(const char* name) {
    for (size_t i = 0; i < labeli; i++) {
        if (strcmp(label_names[i], name) == 0) {
            fprintf(stderr, "%s\n", name);
            return label_symbols[i];
        }
    }

    if (labeli >= 2048) {
        fprintf(stderr, "out of labels\n");
        exit(1);
    }

    fprintf(stderr, "%s:\n", name);

    unsigned long len = strlen(name) + 1;
    label_names[labeli] = malloc(len);
    memcpy(label_names[labeli], name, len);
    label_symbols[labeli] = new_symbol();
    return label_symbols[labeli++];
}

void nomap(void) {
    if (mapi > 0) {
        fprintf(stderr, "expected all maps to be closed before new label or EOF\n");
        exit(1);
    }
}

void begin_map(enum map_type type) {
    if (next().type != TOK_MAP_BEGIN) {
        fprintf(stderr, "expected {\n");
        exit(1);
    }
    push(type);
}

symbol compile(void) {
    symbol entry_point = init_bytecode();

    while (true) {
        struct token tok = next();
        switch (tok.type) {
        case TOK_COMM:
            comm();
            break;
        case TOK_ASSOCL:
            assocl();
            break;
        case TOK_ASSOCR:
            assocr();
            break;
        case TOK_DISTL:
            distl();
            break;
        case TOK_DISTR:
            distr();
            break;
        case TOK_FACTL:
            factl();
            break;
        case TOK_FACTR:
            factr();
            break;
        case TOK_MAPL:
            begin_map(MAP_LEFT_TIMES);
            mapl_begin();
            break;
        case TOK_MAPR:
            begin_map(MAP_RIGHT_TIMES);
            mapr_begin();
            break;
        case TOK_UNITIL:
            unitil();
            break;
        case TOK_UNITIR:
            unitir();
            break;
        case TOK_UNITEL:
            unitel();
            break;
        case TOK_UNITER:
            uniter();
            break;
        case TOK_COMM_PLUS:
            comm_plus();
            break;
        case TOK_ASSOCL_PLUS:
            assocl_plus();
            break;
        case TOK_ASSOCR_PLUS:
            assocr_plus();
            break;
        case TOK_MAPL_PLUS:
            begin_map(MAP_LEFT_PLUS);
            mapl_plus_begin();
            break;
        case TOK_MAPR_PLUS:
            begin_map(MAP_RIGHT_PLUS);
            mapr_plus_begin();
            break;
        case TOK_INL:
            inl();
            break;
        case TOK_INR:
            inr();
            break;
        case TOK_OUT:
            out();
            break;
        case TOK_HALT:
            halt();
            break;
        case TOK_LABEL:
            nomap();
            define_executable_symbol(lookup_label(tok.identifier));
            break;
        case TOK_JUMP:
        fprintf(stderr, "!jump %s\n", tok.identifier);
            nomap();
            jump(lookup_label(tok.identifier));
            break;
        case TOK_MAP_BEGIN:
            fprintf(stderr, "unexpected {\n");
            exit(1);
            break;
        case TOK_MAP_END:
            ; enum map_type type = pop();
            switch (type) {
            case MAP_LEFT_TIMES:
                mapl_end();
                break;
            case MAP_RIGHT_TIMES:
                mapr_end();
                break;
            case MAP_LEFT_PLUS:
                mapl_plus_end();
                break;
            case MAP_RIGHT_PLUS:
                mapr_plus_end();
                break;
            }
            break;
        case TOK_EOF:
            goto eof;
        case TOK_IF:
            nomap();
            struct token a = next();
            struct token b = next();
            fprintf(stderr, "!if %s %s\n", a.identifier, b.identifier);
            symbol aa = lookup_label(a.identifier);
            symbol bb = lookup_label(b.identifier);
            if (a.type != TOK_JUMP || b.type != TOK_JUMP) {
                fprintf(stderr, "arguments to 'if' should be labels\n");
                exit(1);
            }
            jump_if(aa, bb);
            break;
        }
    }
eof:
    nomap();
    finish_bytecode();
    return entry_point;
}

int main(int argc, char** argv) {
    if (argc != 3) {
        fprintf(stderr, "usage: %s <output file> <source file>\n", argv[0]);
        exit(1);
    }
    open_files(argv[2], argv[1]);

    elf_executable();
    symbol entry_point = compile();
    finish_executable(entry_point);

    close_files();
    return 0;
}