package shared

import (
	"io/fs"
	"testing"
	"testing/fstest"

	"gitea.maximumdirect.net/eric/notarius/internal/framework/llm"
	"gitea.maximumdirect.net/eric/notarius/internal/framework/promptfs"
)

func TestSharedPromptFilesReturnsNewSlice(t *testing.T) {
	first := SharedPromptFiles()
	second := SharedPromptFiles()

	if len(first) != 3 || len(second) != 3 {
		t.Fatalf("SharedPromptFiles() lengths = %d and %d, want 3", len(first), len(second))
	}
	first[0].Name = "changed.md"
	if second[0].Name != "common-dnd-system.md" {
		t.Fatalf("SharedPromptFiles() reused descriptor slice: %#v", second)
	}
}

func TestSharedPromptFilesReferenceEmbeddedAssets(t *testing.T) {
	for _, file := range SharedPromptFiles() {
		if file.FS == nil {
			t.Fatalf("SharedPromptFiles() descriptor %q has nil FS", file.Name)
		}
		if _, err := fs.ReadFile(file.FS, file.Path); err != nil {
			t.Fatalf("ReadFile(%q) error = %v, want nil", file.Path, err)
		}
	}
}

func TestHashPartsReferenceSharedPrompts(t *testing.T) {
	assertHashParts(t, "common", CommonHashParts(), []string{
		"assets/prompts/common-dnd-system.md",
		"assets/prompts/common-dnd-transcript.md",
	})
	assertHashParts(t, "reference", ReferenceHashParts(), []string{
		"assets/prompts/common-dnd-references.md",
	})

	for _, part := range append(CommonHashParts(), ReferenceHashParts()...) {
		if _, err := fs.ReadFile(part.FS, part.Path); err != nil {
			t.Fatalf("ReadFile(%q) error = %v, want nil", part.Path, err)
		}
	}
}

func assertHashParts(t *testing.T, name string, parts []llm.AssetHashPart, want []string) {
	t.Helper()
	if len(parts) != len(want) {
		t.Fatalf("%s hash parts length = %d, want %d", name, len(parts), len(want))
	}
	for i, part := range parts {
		if part.Path != want[i] {
			t.Fatalf("%s hash part %d path = %q, want %q", name, i, part.Path, want[i])
		}
		if part.FS == nil {
			t.Fatalf("%s hash part %d has nil FS", name, i)
		}
	}
}

func TestModulePromptFSMountsDNDSharedPrompts(t *testing.T) {
	fsys, err := ModulePromptFS("dnd.test", fstest.MapFS{
		"assets/prompts/dnd.test.yaml": {Data: []byte("id: dnd.test")},
	}, []promptfs.ModulePromptFile{
		{Name: "dnd.test.yaml", Path: "assets/prompts/dnd.test.yaml"},
	})
	if err != nil {
		t.Fatalf("ModulePromptFS() error = %v, want nil", err)
	}

	for _, path := range []string{
		"assets/prompts/dnd.test/dnd.test.yaml",
		"assets/prompts/dnd.test/sharedassets/common-dnd-system.md",
		"assets/prompts/dnd.test/sharedassets/common-dnd-transcript.md",
		"assets/prompts/dnd.test/sharedassets/common-dnd-references.md",
	} {
		if _, err := fs.ReadFile(fsys, path); err != nil {
			t.Fatalf("ReadFile(%q) error = %v, want nil", path, err)
		}
	}
}