/*
 * wwdump — deterministic dump tool for ww source.
 *
 * Reads a .ww file and writes either a token stream or an AST
 * s-expression to stdout, byte-for-byte stable across runs. It is the
 * diff anchor for self-host: the C-side libwcc and the future ww-side
 * frontend must produce the same dump for the same input.
 *
 *   wwdump -t file.ww   tokens, one per line: "<file>:<l>:<c> <kind> [val]"
 *   wwdump -a file.ww   AST as s-expr, one node per line
 *
 * No newlines or trailing whitespace varies by phase of the moon. If
 * the bytes differ, somebody changed the front end.
 */
#include "ww.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

static int
slurp(const char *path, char **outbuf, u64 *outlen)
{
	FILE *f = fopen(path, "rb");
	if (f == NULL) return -1;
	fseek(f, 0, SEEK_END);
	long n = ftell(f);
	fseek(f, 0, SEEK_SET);
	if (n < 0) { fclose(f); return -1; }
	char *b = malloc((size_t)n + 1);
	if (b == NULL) { fclose(f); return -1; }
	if (fread(b, 1, (size_t)n, f) != (size_t)n) { free(b); fclose(f); return -1; }
	b[n] = '\0';
	fclose(f);
	*outbuf = b;
	*outlen = (u64)n;
	return 0;
}

static int
dump_tokens(const char *src, char *buf, u64 len, FILE *out)
{
	Arena *a = newarena();
	Lex l;
	lexinit(&l, a, src, buf, len);
	for (;;) {
		Tok t = lexnext(&l);
		tokprint(out, t);
		if (t.kind == TK_EOF || t.kind == TK_ERR) break;
	}
	int errs = l.errs;
	freearena(a);
	return errs ? 1 : 0;
}

static int
dump_ast(const char *src, char *buf, u64 len, FILE *out)
{
	Arena *a = newarena();
	Lex l;
	Parser p;
	lexinit(&l, a, src, buf, len);
	parserinit(&p, a, &l);
	Node *file = parsefile(&p);
	int errs = l.errs || p.errs;
	if (file) astprint(out, file);
	freearena(a);
	return errs ? 1 : 0;
}

int
main(int argc, char **argv)
{
	int mode = 't';	/* tokens by default */
	const char *src = NULL;
	const char *out = NULL;
	for (int i = 1; i < argc; i++) {
		const char *a = argv[i];
		if (strcmp(a, "-t") == 0) mode = 't';
		else if (strcmp(a, "-a") == 0) mode = 'a';
		else if (strcmp(a, "-o") == 0 && i + 1 < argc) out = argv[++i];
		else if (a[0] == '-') {
			fprintf(stderr, "wwdump: unknown flag %s\n", a);
			return 2;
		}
		else if (src == NULL) src = a;
		else {
			fputs("wwdump: only one input supported\n", stderr);
			return 2;
		}
	}
	if (src == NULL) {
		fputs("usage: wwdump [-t|-a] [-o out] file.ww\n", stderr);
		return 2;
	}

	char *buf;
	u64 len;
	if (slurp(src, &buf, &len) < 0) {
		fprintf(stderr, "wwdump: %s: cannot read\n", src);
		return 1;
	}

	FILE *of = stdout;
	if (out) {
		of = fopen(out, "wb");
		if (of == NULL) {
			fprintf(stderr, "wwdump: cannot open %s\n", out);
			return 1;
		}
	}

	int rc;
	if (mode == 'a') rc = dump_ast(src, buf, len, of);
	else rc = dump_tokens(src, buf, len, of);

	if (of != stdout) fclose(of);
	free(buf);
	return rc;
}