package builder

import (
	"context"
	"os"
	"path/filepath"
	"testing"
)

const aBundle = `{"module":"greeter","version":"1",
  "build":{"artifacts":[
    {"name":"code","kind":"bundle","language":"typescript","entrypoints":["index.js"]}]},
  "resources":[
    {"id":"files","type":"archive","path":"/opt/greeter","artifact":"code"}]}`

// compiling is a runner that behaves like a toolchain: when asked to compile, it leaves output
// where the toolchain says output lands. Without this the pack step has nothing to pack, and the
// test would be asserting on a failure rather than on a build.
type compiling struct{ *recorded }

func (c compiling) run(ctx context.Context, dir, name string, args ...string) (string, error) {
	out, err := c.recorded.run(ctx, dir, name, args...)
	if name != "docker" || len(args) == 0 || args[0] != "run" {
		return out, err
	}
	// **Writes where it was TOLD to**, rather than to a fixed directory. A fake that always wrote
	// to one place would pass whether or not the builder gave each artifact its own — which is the
	// thing being tested.
	where := ""
	for i, a := range args {
		if a == "--outDir" && i+1 < len(args) {
			where = args[i+1]
		}
	}
	if where == "" {
		return out, err
	}
	made := filepath.Join(dir, where)
	if err := os.MkdirAll(made, 0o755); err != nil {
		return "", err
	}
	if err := os.WriteFile(filepath.Join(made, "index.js"), []byte("console.log(1)"), 0o644); err != nil {
		return "", err
	}
	return out, err
}

// **A module says what it is written in, and needs no Dockerfile.** This is the whole point of the
// bundle recipe: the same module previously needed a hand-written recipe repeating an incantation
// that is easy to get wrong in ways that fail somewhere else.

// A bundle naming packages it keeps external is bundled with them as imports, and carries the
// toolchain's node_modules for them — the one case it still does.

// A language whose bundle carries its own dependencies copies nothing in: a Go binary is static.
func TestOnlyALanguageWithARuntimeDirectoryCopiesDependenciesIn(t *testing.T) {
	ts, _ := ToolchainFor("typescript")
	if ts.Dependencies != "/app/runtime" {
		t.Fatalf("typescript bundles run with %q", ts.Dependencies)
	}
	for _, language := range []string{"go", "python"} {
		chain, _ := ToolchainFor(language)
		if chain.Dependencies != "" {
			t.Fatalf("%s copies %q into every bundle, and its bundles carry their own", language, chain.Dependencies)
		}
	}
}

// **Refused before anything is built, naming what to build first.** A base the mesh has not built
// is not a compile that fails on its first line — it is a question somebody can answer, and saying
// it early is the difference between a fixable message and one about a missing image.

// A language the mesh does not build is refused the same way, and names what it can build.

// **One module, two bundles, and neither packs the other.**
//
// The case that matters for real modules: a module is one piece of software and may still carry a
// daemon in one language and tools in another (ADR 0040). An earlier version of this compiled
// every bundle into the toolchain's single output directory, so two of them would overwrite each
// other and then be packed together — one artifact containing both, twice.