#include "gc.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;
}

int
main(int argc, char **argv)
{
	const char *src = NULL;
	const char *out = NULL;
	const char *wwiout = NULL;	/* -I <out.wwi>: M2 export-data producer */
	int testmode = 0;
	int sepmode = 0;		/* -c: #22 M3 separate-compile / primary-
					 * only codegen (emit imported==0 decls
					 * only; treat `.wwi` deps as external) */
	for (int i = 1; i < argc; i++) {
		const char *a = argv[i];
		if (strcmp(a, "-o") == 0 && i + 1 < argc) {
			out = argv[++i];
		} else if (strcmp(a, "-I") == 0 && i + 1 < argc) {
			wwiout = argv[++i];
		} else if (strcmp(a, "-T") == 0) {
			testmode = 1;
		} else if (strcmp(a, "-c") == 0) {
			sepmode = 1;
		} else if (a[0] == '-') {
			fprintf(stderr, "w6c: unknown flag %s\n", a);
			return 2;
		} else if (src == NULL) {
			src = a;
		} else {
			fprintf(stderr, "w6c: only one input supported\n");
			return 2;
		}
	}
	if (src == NULL) {
		fputs("usage: w6c [-T] [-c] [-I out.wwi] [-o out.s] file.ww\n", stderr);
		return 2;
	}

	char *buf;
	u64 len;
	if (slurp(src, &buf, &len) < 0) {
		fprintf(stderr, "w6c: %s: cannot read\n", src);
		return 1;
	}

	Arena *a = newarena();
	Lex l;
	Parser p;
	Checker c;
	Cg cg;

	lexinit(&l, a, src, buf, len);
	parserinit(&p, a, &l);
	Node *file = parsefile(&p);
	if (l.errs || p.errs) return 1;

	check_init(&c, a);
	c.is_test = testmode;
	c.sep_mode = sepmode;
	check_file(&c, file);
	if (c.errs) return 1;

	/* M2 export-data: write the `.wwi` after a clean check, before cgen.
	 * Dead on the live path (no existing invocation passes -I); the
	 * producer's check_exported_type may reject a dangling export. */
	if (wwiout) {
		FILE *wf = fopen(wwiout, "wb");
		if (wf == NULL) {
			fprintf(stderr, "w6c: cannot open %s\n", wwiout);
			return 1;
		}
		if (wwi_emit(&c, wf, file) != 0) { fclose(wf); return 1; }
		fclose(wf);
	}

	FILE *of = stdout;
	if (out) {
		of = fopen(out, "wb");
		if (of == NULL) {
			fprintf(stderr, "w6c: cannot open %s\n", out);
			return 1;
		}
	}

	cg_init(&cg, a);
	cg.sep_mode = sepmode;
	/* #99: wwiout != NULL <=> this is a sep DEP unit (the producer passes
	 * -I to deps only; the root's .wwi is stripped per #69). Gates the
	 * bare-`main` carve-out so only the root/link-entry main stays bare. */
	cg.sep_isdep = (wwiout != NULL);
	cg_file(&cg, of, file);

	if (of != stdout) fclose(of);
	freearena(a);
	free(buf);
	return 0;
}