package birddeploy

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

	"evobgp/internal/store"
)

func TestWriteGenerationPinsCompleteIncludeTree(t *testing.T) {
	active := t.TempDir()
	if err := os.Mkdir(filepath.Join(active, "bird.d"), 0o755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(active, "bird.d", "operator.conf"), []byte("# operator"), 0o644); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(active, "bird.d", "evobgp_removed.conf"), []byte("# removed"), 0o644); err != nil {
		t.Fatal(err)
	}
	gen := filepath.Join(active, ".evobgp-generation-test")
	if err := os.Mkdir(gen, 0o755); err != nil {
		t.Fatal(err)
	}
	fragments := map[string]string{"bird.conf": "include \"bird.d/*.conf\";\n", "bird.d/evobgp_new.conf": "# new"}
	if err := writeGeneration(active, gen, fragments); err != nil {
		t.Fatal(err)
	}
	main, err := os.ReadFile(filepath.Join(gen, "bird.conf"))
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(string(main), filepath.ToSlash(filepath.Join(gen, "bird.d", "*.conf"))) {
		t.Fatalf("include is not pinned to generation: %s", main)
	}
	for _, name := range []string{"operator.conf", "evobgp_new.conf"} {
		if _, err := os.Stat(filepath.Join(gen, "bird.d", name)); err != nil {
			t.Fatalf("%s missing: %v", name, err)
		}
	}
	if _, err := os.Stat(filepath.Join(gen, "bird.d", "evobgp_removed.conf")); !os.IsNotExist(err) {
		t.Fatalf("removed fragment retained: %v", err)
	}
}

func TestWriteGenerationRejectsUnsafePaths(t *testing.T) {
	for _, bad := range []string{"../escape.conf", "bird.d/../../escape.conf", "other.conf"} {
		t.Run(bad, func(t *testing.T) {
			active := t.TempDir()
			gen := filepath.Join(active, ".evobgp-generation-test")
			if err := os.Mkdir(gen, 0o755); err != nil {
				t.Fatal(err)
			}
			fragments := map[string]string{"bird.conf": "router id 192.0.2.1;\n", bad: "bad"}
			if err := writeGeneration(active, gen, fragments); err == nil {
				t.Fatal("unsafe path accepted")
			}
		})
	}
}

func TestWriteGenerationRejectsExternalAndNestedIncludes(t *testing.T) {
	for _, main := range []string{
		`include "/outside/bird.d/peer.conf";` + "\n",
		`include "other/peer.conf";` + "\n",
		`include "bird.d/peer.conf"; include "other.conf";` + "\n",
		`router id 192.0.2.1; include "/outside/peer.conf";` + "\n",
		"/*\ninclude \"bird.d/decoy.conf\";\n*/\nrouter id 192.0.2.1; include \"/outside/live.conf\";\n",
	} {
		active := t.TempDir()
		gen := filepath.Join(active, ".evobgp-generation-test")
		if err := os.Mkdir(gen, 0o755); err != nil {
			t.Fatal(err)
		}
		if err := writeGeneration(active, gen, map[string]string{"bird.conf": main}); err == nil {
			t.Fatalf("include accepted: %s", main)
		}
	}
	active := t.TempDir()
	if err := os.Mkdir(filepath.Join(active, "bird.d"), 0o755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(active, "bird.d", "operator.conf"), []byte(`define X=1; include "/outside/foo.conf";`), 0o644); err != nil {
		t.Fatal(err)
	}
	gen := filepath.Join(active, ".evobgp-generation-test")
	if err := os.Mkdir(gen, 0o755); err != nil {
		t.Fatal(err)
	}
	if err := writeGeneration(active, gen, map[string]string{"bird.conf": "router id 192.0.2.1;\n"}); err == nil {
		t.Fatal("nested operator include accepted")
	}
}

func TestCountIncludeTokensIgnoresCommentsAndStrings(t *testing.T) {
	content := "# include \"ignored.conf\";\n" +
		"/* include \"ignored.conf\"; */\n" +
		"define note = \"include in string\";\n" +
		"include \"bird.d/real.conf\";\n"
	if got := countIncludeTokens(content); got != 1 {
		t.Fatalf("want one include, got %d", got)
	}
}

func TestIncludeAfterBackslashStringCannotHideNestedInclude(t *testing.T) {
	content := `define note = "\";` + "\n" + `include "/outside/hidden.conf";` + "\n"
	if got := countIncludeTokens(content); got != 1 {
		t.Fatalf("live include hidden after quoted backslash: %d", got)
	}
	active := t.TempDir()
	gen := filepath.Join(active, ".evobgp-generation-test")
	if err := os.Mkdir(gen, 0o755); err != nil {
		t.Fatal(err)
	}
	fragments := map[string]string{"bird.conf": "router id 192.0.2.1;\n", "bird.d/evobgp_test.conf": content}
	if err := writeGeneration(active, gen, fragments); err == nil {
		t.Fatal("nested external include accepted after quoted backslash")
	}
}

func TestWriteGenerationRewritesAbsoluteActiveInclude(t *testing.T) {
	active := t.TempDir()
	gen := filepath.Join(active, ".evobgp-generation-test")
	if err := os.Mkdir(gen, 0o755); err != nil {
		t.Fatal(err)
	}
	inc := filepath.ToSlash(filepath.Join(active, "bird.d", "peer.conf"))
	main := "include \"" + inc + "\";\n"
	if err := writeGeneration(active, gen, map[string]string{"bird.conf": main, "bird.d/peer.conf": "# peer"}); err != nil {
		t.Fatal(err)
	}
	b, err := os.ReadFile(filepath.Join(gen, "bird.conf"))
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(string(b), filepath.ToSlash(filepath.Join(gen, "bird.d", "peer.conf"))) {
		t.Fatalf("absolute include not rewritten: %s", b)
	}
}

func TestWriteGenerationRejectsSymlinkBirdDRoot(t *testing.T) {
	active := t.TempDir()
	outside := t.TempDir()
	if err := os.WriteFile(filepath.Join(outside, "operator.conf"), []byte("# operator"), 0o644); err != nil {
		t.Fatal(err)
	}
	if err := os.Symlink(outside, filepath.Join(active, "bird.d")); err != nil {
		t.Skipf("symlinks unavailable: %v", err)
	}
	old := []byte("router id 192.0.2.2;\n")
	if err := os.WriteFile(filepath.Join(active, "bird.conf"), old, 0o644); err != nil {
		t.Fatal(err)
	}
	gen := filepath.Join(active, ".evobgp-generation-test")
	if err := os.Mkdir(gen, 0o755); err != nil {
		t.Fatal(err)
	}
	if err := writeGeneration(active, gen, map[string]string{"bird.conf": "router id 192.0.2.1;\n"}); err == nil {
		t.Fatal("bird.d symlink accepted")
	}
	current, err := os.ReadFile(filepath.Join(active, "bird.conf"))
	if err != nil {
		t.Fatal(err)
	}
	if string(current) != string(old) {
		t.Fatalf("active config changed: %s", current)
	}
	if _, err := os.ReadFile(filepath.Join(outside, "operator.conf")); err != nil {
		t.Fatalf("operator snippet changed: %v", err)
	}
}

func TestApplyRevisionRejectsSymlinkMain(t *testing.T) {
	active := t.TempDir()
	target := filepath.Join(t.TempDir(), "operator-bird.conf")
	old := []byte("router id 192.0.2.2;\n")
	if err := os.WriteFile(target, old, 0o644); err != nil {
		t.Fatal(err)
	}
	if err := os.Symlink(target, filepath.Join(active, "bird.conf")); err != nil {
		t.Skipf("symlinks unavailable: %v", err)
	}
	err := ApplyRevision(context.Background(), nil, &store.Revision{PreviewFragments: map[string]string{"bird.conf": "router id 192.0.2.1;\n"}}, Config{ActiveDir: active})
	if err == nil || !strings.Contains(err.Error(), "regular file") {
		t.Fatalf("want explicit symlink rejection, got %v", err)
	}
	info, err := os.Lstat(filepath.Join(active, "bird.conf"))
	if err != nil {
		t.Fatal(err)
	}
	if info.Mode()&os.ModeSymlink == 0 {
		t.Fatal("active symlink replaced")
	}
	current, err := os.ReadFile(target)
	if err != nil {
		t.Fatal(err)
	}
	if string(current) != string(old) {
		t.Fatalf("operator target changed: %s", current)
	}
}