/* SPDX-License-Identifier: Unlicense
 *
 * This program translates Sierra m68k assembly dialect to GNU AS m68k dialect.
 *
 * NOTE: Unicode is not supported, ASCII only.
 */

#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

#define OK 0
#define ERR 2

enum tok_kind {
    TK_NONE = 0,
    TK_SPACE,
    TK_TAB,
    TK_CR,
    TK_LF,
    TK_DOT,
    TK_COMMA,
    TK_PLUS,
    TK_MINUS,
    TK_EQ,
    TK_COLON,
    TK_ASTERISK,
    TK_STRING,
    TK_ALNUM,
    TK_NUMDEC,
    TK_NUMOCT,
    TK_NUMHEX,
    TK_PARENL,
    TK_PARENR,
    TK_COMMENT_ASTERISK,
    TK_COMMENT_SEMICOLON,
};

struct tok {
    enum tok_kind kind;
    size_t offset;
    size_t length;
};

enum lex_error {
    LE_NONE = 0,
};

struct lex {
    // Input data buffer
    FILE *parsed_input_stream;
    char *parsed_input;
    size_t parsed_input_size;
    // Tokens table
    FILE *tokbuf_stream;
    struct tok *tokbuf;
    size_t tokbuf_size;
    // State
    size_t offset;
    enum lex_error error;
};

enum stmt_kind {
    SK_NONE = 0,
    SK_LABEL,
    SK_INSTRUCTION,
    SK_TEXT,
    SK_DIR_FILE,
    SK_DIR_TEXT,
    SK_DIR_ALIGN,
    SK_DIR_DEF_ENDEF,
    SK_DIR_GLOBL,
    SK_DIR_LINE,
};

enum opcode {
    OPCODE_NONE,
    OPCODE_NOP,
};

enum opsize {
    OPSIZE_NONE = 0,
    OPSIZE_S,
    OPSIZE_B,
    OPSIZE_W,
    OPSIZE_L,
};

enum arg_kind {
    ARG_NONE = 0,
    ARG_DN,
    ARG_AN,
    ARG_AN_ADDR,
    ARG_AN_ADDR_INCR,
    ARG_AN_ADDR_DECR,
    ARG_AN_ADDR_16,
    ARG_AN_ADDR_8_XN,
    ARG_ADDR_WORD,
    ARG_ADDR_LONG,
    ARG_ADDR_UNSPEC,
    ARG_PC_ADDR_16,
    ARG_PC_ADDR_8_XN,
    ARG_IMMEDIATE,
};

struct arg_8_xn {
    int8_t val;
    int8_t an;
    int8_t xi;
};

struct instruction {
    enum opcode opcode;
    enum opsize opsize;
    enum arg_kind arg1_kind, arg2_kind;
    union {
        int32_t imm, addr;
        struct arg_8_xn arg_8_xn; // For (d,An,Xi) and (d,PC,Xn)
    } arg1, arg2;
};

struct def_endef {
    size_t sym_id;
    size_t tag_sym_id;
    int32_t size;
    int32_t storage_class;
    int32_t type;
};

struct stmt {
    enum stmt_kind kind;
    union {
        struct instruction instruction;
        int32_t align;
        size_t globl_sym_id;
        size_t file_sym_id;
    };
    size_t first_token, num_tokens; // Statement tokens span, may be NULL
    size_t comment_token;
};

struct symbol {
    size_t offset; // Byte offset in continuous null terminated symbol buffer
    // Instead of strcmp every item in symtab we can compare hashes and get O(N)
    // for search.
    uint32_t hash;
};

struct pars {
    struct lex *lex;
    // Statement table
    FILE *stmttab_stream;
    struct stmt *stmttab;
    size_t stmttab_size;
    // Symbol table
    FILE *symtab_stream;
    struct sym *symtab;
    size_t symtab_size;
    // Symbol buffer for symbol table
    FILE *symbuf_stream;
    char *symbuf;
    size_t symbuf_size;
};

struct assem {
    struct pars *pars;
};

static int lex_init(struct lex *const self)
{
    (void) self;
    return OK;
}

static int lex_next(struct lex *const self)
{
    (void) self;
    return OK;
}

static void lex_destroy(struct lex *const self)
{
    (void) self;
}

static int pars_init(struct pars *const self, struct lex *const lex)
{
    (void) self;
    (void) lex;
    return OK;
}

static int pars_run(struct pars *const self, FILE *const stream)
{
    (void) self;
    (void) stream;
    return OK;
}

static void pars_destroy(struct pars *const self)
{
    (void) self;
}

static int assem_init(struct assem *const self, struct pars *const pars)
{
    (void) self;
    (void) pars;
    return OK;
}

static int assem_resolve(struct assem *const self)
{
    (void) self;
    return OK;
}

static int assem_emit(struct assem *const self, FILE *const stream)
{
    (void) self;
    (void) stream;
    return OK;
}

static void assem_destroy(struct assem *const self)
{
    (void) self;
}

int main(const int argc, char *const argv[])
{
    // No fucks given about arguments for now
    (void)argc;
    (void)argv;
    struct lex lex;
    struct pars pars;
    if (OK != lex_init(&lex)) {
        return EXIT_FAILURE;
    }
    // Chain lexer and parser
    if (OK != pars_init(&pars, &lex)) {
        lex_destroy(&lex);
        return EXIT_FAILURE;
    }
    // Parse assembly program text (tokenize + parse)
    if (OK != pars_run(&pars, stdin)) {
        pars_destroy(&pars);
        lex_destroy(&lex);
        return EXIT_FAILURE;
    }
    struct assem assem;
    // Allocate adn populate code table and metadata table from parsed data
    if (OK != assem_init(&assem, &pars)) {
        pars_destroy(&pars);
        lex_destroy(&lex);
        return EXIT_FAILURE;
    }
    // Resolve all ambiguities
    if (OK != assem_resolve(&assem)) {
        assem_destroy(&assem);
        pars_destroy(&pars);
        lex_destroy(&lex);
        return EXIT_FAILURE;
    }
    // Emit unambiguous assembly language program text for specified dialect
    // (currently m68k GNU AS only is supported)
    if (OK != assem_emit(&assem, stdout)) {
        assem_destroy(&assem);
        pars_destroy(&pars);
        lex_destroy(&lex);
        return EXIT_FAILURE;
    }
    assem_destroy(&assem);
    pars_destroy(&pars);
    lex_destroy(&lex);
}