#include <stdio.h>

#include "apfl.h"

#include "format.h"

#define POSFMT "%d:%d"
#define POSARGS error.position.line, error.position.col
#define POS2ARGS error.position2.line, error.position2.col

#define TRY(x) do { if (!(x)) return false; } while (0)

const char *
apfl_error_type_name(enum apfl_error_type type)
{
    switch (type) {
    case APFL_ERR_MALLOC_FAILED:
        return "APFL_ERR_MALLOC_FAILED";
    case APFL_ERR_INPUT_ERROR:
        return "APFL_ERR_INPUT_ERROR";
    case APFL_ERR_UNEXPECTED_EOF:
        return "APFL_ERR_UNEXPECTED_EOF";
    case APFL_ERR_EXPECTED_EQ_AFTER_COLON:
        return "APFL_ERR_EXPECTED_EQ_AFTER_COLON";
    case APFL_ERR_UNEXPECTED_BYTE:
        return "APFL_ERR_UNEXPECTED_BYTE";
    case APFL_ERR_UNEXPECTED_BYTE_IN_NUMBER:
        return "APFL_ERR_UNEXPECTED_BYTE_IN_NUMBER";
    case APFL_ERR_EXPECTED_DIGIT:
        return "APFL_ERR_EXPECTED_DIGIT";
    case APFL_ERR_EXPECTED_HEX_IN_HEX_ESCAPE:
        return "APFL_ERR_EXPECTED_HEX_IN_HEX_ESCAPE";
    case APFL_ERR_INVALID_ESCAPE_SEQUENCE:
        return "APFL_ERR_INVALID_ESCAPE_SEQUENCE";
    case APFL_ERR_NO_LINEBREAK_AFTER_CONTINUE_LINE:
        return "APFL_ERR_NO_LINEBREAK_AFTER_CONTINUE_LINE";
    case APFL_ERR_UNEXPECTED_TOKEN:
        return "APFL_ERR_UNEXPECTED_TOKEN";
    case APFL_ERR_MISMATCHING_CLOSING_BRACKET:
        return "APFL_ERR_MISMATCHING_CLOSING_BRACKET";
    case APFL_ERR_UNEXPECTED_EOF_AFTER_TOKEN:
        return "APFL_ERR_UNEXPECTED_EOF_AFTER_TOKEN";
    case APFL_ERR_STATEMENTS_BEFORE_PARAMETERS:
        return "APFL_ERR_STATEMENTS_BEFORE_PARAMETERS";
    case APFL_ERR_EMPTY_ASSIGNMENT_BEFORE_PARAMETERS:
        return "APFL_ERR_EMPTY_ASSIGNMENT_BEFORE_PARAMETERS";
    case APFL_ERR_UNEXPECTED_EXPRESSION:
        return "APFL_ERR_UNEXPECTED_EXPRESSION";
    case APFL_ERR_INVALID_ASSIGNMENT_LHS:
        return "APFL_ERR_INVALID_ASSIGNMENT_LHS";
    case APFL_ERR_EMPTY_ASSIGNMENT:
        return "APFL_ERR_EMPTY_ASSIGNMENT";
    case APFL_ERR_ONLY_ONE_EXPAND_ALLOWED:
        return "APFL_ERR_ONLY_ONE_EXPAND_ALLOWED";
    case APFL_ERR_UNEXPECTED_CONSTANT_IN_MEMBER_ACCESS:
        return "APFL_ERR_UNEXPECTED_CONSTANT_IN_MEMBER_ACCESS";
    case APFL_ERR_UNEXPECTED_EXPR_IN_MEMBER_ACCESS:
        return "APFL_ERR_UNEXPECTED_EXPR_IN_MEMBER_ACCESS";
    case APFL_ERR_UNEXPECTED_BLANK_IN_MEMBER_ACCESS:
        return "APFL_ERR_UNEXPECTED_BLANK_IN_MEMBER_ACCESS";
    case APFL_ERR_NOT_IMPLEMENTED:
        return "APFL_ERR_NOT_IMPLEMENTED";
    }

    return "<unknown error>";
}

const char *
apfl_error_as_const_string(struct apfl_error error)
{
    switch (error.type) {
    case APFL_ERR_MALLOC_FAILED:
        return apfl_messages.could_not_alloc_mem;
    case APFL_ERR_INPUT_ERROR:
        return apfl_messages.input_error_while_parsing;
    case APFL_ERR_UNEXPECTED_EOF:
        return apfl_messages.unexpected_end_of_file;
    case APFL_ERR_NOT_IMPLEMENTED:
        return apfl_messages.feature_not_implemented;
    default:
        return NULL;
    }
}

static bool
format_error(struct apfl_format_writer w, struct apfl_error error)
{
    switch (error.type) {
    case APFL_ERR_MALLOC_FAILED:
        return apfl_format_put_string(w, apfl_messages.could_not_alloc_mem);
    case APFL_ERR_INPUT_ERROR:
        return apfl_format_put_string(w, apfl_messages.input_error_while_parsing);
    case APFL_ERR_UNEXPECTED_EOF:
        return apfl_format_put_string(w, apfl_messages.unexpected_end_of_file);
    case APFL_ERR_EXPECTED_EQ_AFTER_COLON:
        TRY(apfl_format_put_string(w, "Expected '=' after ':' at "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_UNEXPECTED_BYTE:
        TRY(apfl_format_put_string(w, "Unexpected byte '"));
        TRY(apfl_format_put_char(w, error.byte));
        TRY(apfl_format_put_string(w, "' (0x"));
        TRY(apfl_format_put_hexbyte(w, (unsigned char)error.byte));
        TRY(apfl_format_put_string(w, ") at "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_UNEXPECTED_BYTE_IN_NUMBER:
        TRY(apfl_format_put_string(w, "Unexpected byte '"));
        TRY(apfl_format_put_char(w, error.byte));
        TRY(apfl_format_put_string(w, "' while parsing number at "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_EXPECTED_DIGIT:
        TRY(apfl_format_put_string(w, "Expected a digit at "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_EXPECTED_HEX_IN_HEX_ESCAPE:
        TRY(apfl_format_put_string(w, "Expected a hex-digit in hex escape at "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_INVALID_ESCAPE_SEQUENCE:
        TRY(apfl_format_put_string(w, "Invalid escape sequence \\"));
        TRY(apfl_format_put_char(w, error.byte));
        TRY(apfl_format_put_string(w, " at "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_NO_LINEBREAK_AFTER_CONTINUE_LINE:
        TRY(apfl_format_put_string(w, "No line break (after optional comments) after \\ at "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_UNEXPECTED_TOKEN:
        TRY(apfl_format_put_string(w, "Unexpected `"));
        TRY(apfl_format_put_string(w, apfl_token_type_name(error.token_type)));
        TRY(apfl_format_put_string(w, "` token at "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_MISMATCHING_CLOSING_BRACKET:
        TRY(apfl_format_put_string(w, "Closing `"));
        TRY(apfl_format_put_string(w, apfl_token_type_name(error.token_type)));
        TRY(apfl_format_put_string(w, "` token at "));
        TRY(apfl_format_put_pos(w, error.position));
        TRY(apfl_format_put_string(w, "Does not match opening `"));
        TRY(apfl_format_put_string(w, apfl_token_type_name(error.token_type2)));
        TRY(apfl_format_put_string(w, "` at "));
        TRY(apfl_format_put_pos(w, error.position2));
        return true;
    case APFL_ERR_UNEXPECTED_EOF_AFTER_TOKEN:
        TRY(apfl_format_put_string(w, "Unexpected end of file after `"));
        TRY(apfl_format_put_string(w, apfl_token_type_name(error.token_type)));
        TRY(apfl_format_put_string(w, "` token at "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_STATEMENTS_BEFORE_PARAMETERS:
        TRY(apfl_format_put_string(w, "Unexpected statements before parameters near "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_EMPTY_ASSIGNMENT_BEFORE_PARAMETERS:
        TRY(apfl_format_put_string(w, "Unexpected empty assignment before parameters near "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_UNEXPECTED_EXPRESSION:
        TRY(apfl_format_put_string(w, "Unexpected expression near "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_INVALID_ASSIGNMENT_LHS:
        TRY(apfl_format_put_string(w, "Invalid left hand side of assignment near "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_EMPTY_ASSIGNMENT:
        TRY(apfl_format_put_string(w, "Empty assignment at "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_ONLY_ONE_EXPAND_ALLOWED:
        TRY(apfl_format_put_string(w, "Only one expansion (~) is allowed per level, near "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_UNEXPECTED_CONSTANT_IN_MEMBER_ACCESS:
        TRY(apfl_format_put_string(w, "Unexpected constant in member access near "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_UNEXPECTED_EXPR_IN_MEMBER_ACCESS:
        TRY(apfl_format_put_string(w, "Unexpected expression in member access near "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_UNEXPECTED_BLANK_IN_MEMBER_ACCESS:
        TRY(apfl_format_put_string(w, "Unexpected blank (\"_\") in member access near "));
        TRY(apfl_format_put_pos(w, error.position));
        return true;
    case APFL_ERR_NOT_IMPLEMENTED:
        TRY(apfl_format_put_string(w, apfl_messages.feature_not_implemented));
        return true;
    }

    TRY(apfl_format_put_string(w, "Unknown error "));
    TRY(apfl_format_put_int(w, (int)error.type));
    return true;
}

bool
apfl_error_print(struct apfl_error error, FILE *file)
{
    struct apfl_format_writer w = apfl_format_file_writer(file);
    TRY(format_error(w, error));
    TRY(apfl_format_put_char(w, '\n'));
    return true;
}

bool
apfl_error_as_string(struct apfl_error error, struct apfl_allocator allocator, struct apfl_string *out)
{
    struct apfl_string_builder builder;
    apfl_string_builder_init(allocator, &builder);
    TRY(format_error(apfl_format_string_writer(&builder), error));
    *out = apfl_string_builder_move_string(&builder);
    return true;
}

struct apfl_error
apfl_error_simple(enum apfl_error_type type)
{
    return (struct apfl_error) { .type = type };
}

bool
apfl_error_is_fatal_type(enum apfl_error_type type)
{
    switch (type) {
    case APFL_ERR_MALLOC_FAILED:
    case APFL_ERR_INPUT_ERROR:
        return true;
    default:
        return false;
    }
}