// dirstest — exercises lib/dirs against an env state pre-arranged by
// the C driver (test/wcc/975_dirs_run.c).
//
// Pre-arranged env (set via setenv/unsetenv before exec'ing
// `ww run lib/dirs/dirstest.ww`; see 975_dirs_run.c):
//
//   HOME             = <tmpl>            (mkdtemp'd /tmp/wwdirs-XXXXXX)
//   XDG_CONFIG_HOME  = <tmpl>/cfg        (absolute → XDG branch)
//   XDG_CACHE_HOME   = "relative/path"   (non-abs → fallback to HOME)
//   XDG_DATA_HOME    unset               (fallback to HOME)
//   XDG_STATE_HOME   unset               (fallback to HOME)
//   WW_TEST_TMPDIR   = <tmpl>            (so this fixture can compute
//                                         the expected paths)
//
// Cohorts (one @test fn per row, in numeric order from main):
//
//   1. config("myapp")  — XDG-set+absolute  → <tmpl>/cfg/myapp
//   2. cache("myapp")   — XDG-set+relative  → <tmpl>/.cache/myapp        (abs-check fallback)
//   3. data("myapp")    — XDG-unset         → <tmpl>/.local/share/myapp  (HOME fallback)
//   4. state("myapp")   — XDG-unset         → <tmpl>/.local/state/myapp  (HOME fallback)
//
// Static-buffer gotcha: dirs.config / dirs.cache / dirs.data /
// dirs.state all return views into the same module-level pathbuf.
// Each @test calls EXACTLY ONE dirs.* function, builds its expected
// string into a separate `scratch: [256]u8` BEFORE that call, and
// asserts immediately. Don't call two dirs.* fns and compare across
// — the second clobbers the first's view.
//
// A failing row aborts via the assert/abort builtin (task #5 @test
// conversion).
//
// Don't `use io;` here — lib/os and lib/io collide on read/write/
// close (task #17). We need only os.getenv.

package dirs_test;

import dirs;
import os;



fn streq(a: str, b: str) bool = {
	if (a.len != b.len) { return false; };
	let i: i32 = 0;
	for (i < a.len) {
		if (a[i] != b[i]) { return false; };
		i += 1;
	};
	return true;
};

// scratch — local buffer for expected-path construction. Independent
// of dirs.pathbuf; both views stay valid through the streq compare
// because they live in different buffers.
let scratch: [256]u8;

fn putscratch(off: i32, s: str) i32 = {
	let i: i32 = 0;
	for (i < s.len) {
		if (off + i >= 255) { break; };
		scratch[off + i] = s[i];
		i += 1;
	};
	return off + i;
};

// expected — build "<tmpl>/<sub>/<prog>" into scratch and return a
// view. Mirrors dirs.build but writes into our scratch buffer so
// the expected and got views can be compared without aliasing.
fn expected(tmpl: str, sub: str, prog: str) str = {
	let off: i32 = 0;
	off = putscratch(off, tmpl);
	if (off < 255) { scratch[off] = 47u8; off += 1; };	// '/'
	off = putscratch(off, sub);
	if (off < 255) { scratch[off] = 47u8; off += 1; };
	off = putscratch(off, prog);
	let r: str;
	r.ptr = &scratch[0];
	r.len = off;
	return r;
};

fn gettmpdir() str = {
	match (os.getenv("WW_TEST_TMPDIR")) {
	case let s: str => return s;
	case void => {
		abort();
		let empty: str;
		return empty;
	};
	};
};

// ---- 1: XDG_CONFIG_HOME=<tmpl>/cfg → <tmpl>/cfg/myapp --------------

@test fn test_config_xdg_set() void = {
	let tmpl = gettmpdir();
	let exp = expected(tmpl, "cfg", "myapp");
	let got = dirs.config("myapp");
	assert(!(!streq(got, exp)));
};

// ---- 2: XDG_CACHE_HOME="relative/path" → fallback to $HOME/.cache --
//
// Exercises Hare's `if (!path::abs(path)) yield;` branch — a
// non-absolute XDG_*_HOME silently falls through to the HOME path.

@test fn test_cache_xdg_relative_fallback() void = {
	let tmpl = gettmpdir();
	let exp = expected(tmpl, ".cache", "myapp");
	let got = dirs.cache("myapp");
	assert(!(!streq(got, exp)));
};

// ---- 3: XDG_DATA_HOME unset → fallback to $HOME/.local/share -------

@test fn test_data_unset_fallback() void = {
	let tmpl = gettmpdir();
	let exp = expected(tmpl, ".local/share", "myapp");
	let got = dirs.data("myapp");
	assert(!(!streq(got, exp)));
};

// ---- 4: XDG_STATE_HOME unset → fallback to $HOME/.local/state ------

@test fn test_state_unset_fallback() void = {
	let tmpl = gettmpdir();
	let exp = expected(tmpl, ".local/state", "myapp");
	let got = dirs.state("myapp");
	assert(!(!streq(got, exp)));
};