#include "repl.h"

#include "eval.h"
#include "memory_stream.h"
#include "print.h"
#include "read.h"

#include <assert.h>
#include <stdio.h>

#define PROMPT "> "

static int read_line(char buffer[REPL_IO_BUFFER_SIZE])
{
	for (unsigned i = 0; i < REPL_IO_BUFFER_SIZE; ++i) {
		const int c = getchar();
		switch (c) {
		case EOF:
			return EOF;
		case '\n':
			return (int)i;
		default:
			buffer[i] = (char)c;
			break;
		}
	}
	assert(false);
	return -2;
}

void repl_init(repl_t *repl)
{
	am_init(&repl->am);
}

int repl_run(repl_t *repl)
{
	int len;
	memory_stream_t input;

	while (true) {
		fputs(PROMPT, stdout);

		len = read_line(repl->io_buffer);
		if (len < 0) {
			fputc('\n', stdout);
			return 0;
		}
		memory_stream_init(&input, (const uint8_t *)repl->io_buffer, len);
		read(&repl->am, (stream_t *)&input);

		eval(&repl->am);

		len = print(&repl->am, repl->io_buffer, REPL_IO_BUFFER_SIZE - 1);
		repl->io_buffer[len] = '\n';
		fwrite(repl->io_buffer, 1, len + 1, stdout);
	}
}