package mapping

import (
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"
)

// sdkPath is the one third-party import this package is allowed: the payload
// shapes it translates to and from.
const sdkPath = "code.gitea.io/sdk/gitea"

// The bridge translates values and nothing else: no network, no filesystem, no
// clock, no configuration. Every one of those is a caller's to supply, which is
// what lets this package be reasoned about and tested without a Gitea anywhere.
//
// THE RULE THIS TEST USED TO MAKE was stronger and is no longer true. The
// shapes lived in internal/wire, which imported the standard library and
// nothing else, so "the bridge cannot reach a transport" held by construction:
// there was nothing in its dependency graph that could open a socket. The SDK's
// types come with the SDK's client attached, so the graph now contains an HTTP
// client whatever this package does with it — and a test that claimed otherwise
// would be a test that lies.
//
// So it asserts the part that survives, which is also the part that catches a
// real mistake: what THIS package reaches for. DIRECT imports, not the
// dependency walk internal/issue does — the domain reaches os through
// internal/project and that is the domain's business. A transport that grew a
// helper here, or a lookup that quietly opened a config file, is what this
// catches, and it still fails on `os`, on `net/http` and on internal/gitea.
func TestTheBridgeTranslatesAndNothingElse(t *testing.T) {
	forbidden := map[string]string{
		"net/http":  "an HTTP call belongs in the transport",
		"net":       "an HTTP call belongs in the transport",
		"os":        "a pure function reads no file and no environment",
		"os/exec":   "nothing here shells out",
		"io/ioutil": "a pure function reads no file",
		"git.noodles.cam/claude-skills/marketplace/cli/internal/gitea":   "the transport imports this package, never the reverse",
		"git.noodles.cam/claude-skills/marketplace/cli/internal/config":  "credentials and repositories are the transport's",
		"git.noodles.cam/claude-skills/marketplace/cli/internal/project": "nothing here resolves a path",
	}
	allowed := map[string]bool{
		sdkPath: true,
		"git.noodles.cam/claude-skills/marketplace/cli/internal/issue": true,
		"git.noodles.cam/claude-skills/marketplace/cli/internal/wire":  true,
	}

	for _, dep := range directImports(t) {
		if why, bad := forbidden[dep]; bad {
			t.Errorf("mapping imports %s — %s", dep, why)
			continue
		}
		// A standard-library import path has no dot in its first element,
		// because it has no domain name in front of it. Everything else has to
		// be named above: one third party is a decision, two is a habit.
		first, _, _ := strings.Cut(dep, "/")
		if strings.Contains(first, ".") && !allowed[dep] {
			t.Errorf("mapping imports %s — the only payload vocabulary here is %s", dep, sdkPath)
		}
	}
}

// The clock is the caller's, and `time` alone can no longer say so: the SDK
// hands over a time.Time, so this package imports the package to format one
// back into the string an issue file holds. What it must never do is ASK what
// time it is — a `synced:` stamped here would be stamped at translation rather
// than at the write it describes, and two issues pushed in one run would carry
// two different times for one run.
//
// The source, then, rather than the import graph: the difference between
// formatting a timestamp and having a clock is not visible in `go list`.
func TestTheBridgeHasNoClock(t *testing.T) {
	for _, path := range sourceFiles(t) {
		raw, err := os.ReadFile(path)
		if err != nil {
			t.Fatal(err)
		}
		for _, banned := range []string{"time.Now(", "time.Since(", "time.Until("} {
			if strings.Contains(string(raw), banned) {
				t.Errorf("%s calls %s) — the clock belongs to the caller", filepath.Base(path), banned)
			}
		}
	}
}

func directImports(t *testing.T) []string {
	t.Helper()
	out, err := exec.Command("go", "list", "-f", `{{join .Imports "\n"}}`, ".").Output()
	if err != nil {
		t.Fatalf("go list: %v", err)
	}
	return strings.Fields(string(out))
}

// sourceFiles is this package's own .go files, tests excluded: a test may look
// at a clock, and one of them does.
func sourceFiles(t *testing.T) []string {
	t.Helper()
	out, err := exec.Command("go", "list", "-f", `{{range .GoFiles}}{{.}}
{{end}}`, ".").Output()
	if err != nil {
		t.Fatalf("go list: %v", err)
	}
	var paths []string
	for _, name := range strings.Fields(string(out)) {
		paths = append(paths, name)
	}
	if len(paths) == 0 {
		t.Fatal("go list named no source files — this test would pass on an empty package")
	}
	return paths
}