package config

import (
	"encoding/json"
	"os"
	"path/filepath"
	"testing"

	"banger/internal/paths"
	"banger/internal/runtimebundle"
)

func TestLoadDerivesArtifactPathsFromRuntimeDir(t *testing.T) {
	runtimeDir := t.TempDir()
	meta := runtimebundle.BundleMetadata{
		FirecrackerBin:    "bin/firecracker",
		SSHKeyPath:        "keys/id_ed25519",
		NamegenPath:       "bin/namegen",
		CustomizeScript:   "scripts/customize.sh",
		VSockAgentPath:    "bin/banger-vsock-agent",
		DefaultPackages:   "config/packages.apt",
		DefaultRootfs:     "images/rootfs-docker.ext4",
		DefaultWorkSeed:   "images/rootfs-docker.work-seed.ext4",
		DefaultKernel:     "kernels/vmlinux",
		DefaultInitrd:     "kernels/initrd.img",
		DefaultModulesDir: "modules/current",
	}
	for _, rel := range []string{
		meta.FirecrackerBin,
		meta.SSHKeyPath,
		meta.NamegenPath,
		meta.CustomizeScript,
		meta.VSockAgentPath,
		meta.DefaultPackages,
		meta.DefaultRootfs,
		meta.DefaultWorkSeed,
		meta.DefaultKernel,
		meta.DefaultInitrd,
		filepath.Join(meta.DefaultModulesDir, "modules.dep"),
	} {
		path := filepath.Join(runtimeDir, rel)
		if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
			t.Fatalf("mkdir %s: %v", filepath.Dir(path), err)
		}
		if err := os.WriteFile(path, []byte("test"), 0o644); err != nil {
			t.Fatalf("write %s: %v", path, err)
		}
	}
	data, err := json.Marshal(meta)
	if err != nil {
		t.Fatalf("Marshal: %v", err)
	}
	if err := os.WriteFile(filepath.Join(runtimeDir, runtimebundle.BundleMetadataFile), data, 0o644); err != nil {
		t.Fatalf("write bundle metadata: %v", err)
	}

	t.Setenv("BANGER_RUNTIME_DIR", runtimeDir)
	cfg, err := Load(paths.Layout{ConfigDir: t.TempDir()})
	if err != nil {
		t.Fatalf("Load: %v", err)
	}

	if cfg.RuntimeDir != runtimeDir {
		t.Fatalf("RuntimeDir = %q, want %q", cfg.RuntimeDir, runtimeDir)
	}
	if cfg.FirecrackerBin != filepath.Join(runtimeDir, meta.FirecrackerBin) {
		t.Fatalf("FirecrackerBin = %q", cfg.FirecrackerBin)
	}
	if cfg.SSHKeyPath != filepath.Join(runtimeDir, meta.SSHKeyPath) {
		t.Fatalf("SSHKeyPath = %q", cfg.SSHKeyPath)
	}
	if cfg.NamegenPath != filepath.Join(runtimeDir, meta.NamegenPath) {
		t.Fatalf("NamegenPath = %q", cfg.NamegenPath)
	}
	if cfg.CustomizeScript != filepath.Join(runtimeDir, meta.CustomizeScript) {
		t.Fatalf("CustomizeScript = %q", cfg.CustomizeScript)
	}
	if cfg.VSockAgentPath != filepath.Join(runtimeDir, meta.VSockAgentPath) {
		t.Fatalf("VSockAgentPath = %q", cfg.VSockAgentPath)
	}
	if cfg.DefaultRootfs != filepath.Join(runtimeDir, meta.DefaultRootfs) {
		t.Fatalf("DefaultRootfs = %q", cfg.DefaultRootfs)
	}
	if cfg.DefaultWorkSeed != filepath.Join(runtimeDir, meta.DefaultWorkSeed) {
		t.Fatalf("DefaultWorkSeed = %q", cfg.DefaultWorkSeed)
	}
	if cfg.DefaultBaseRootfs != filepath.Join(runtimeDir, meta.DefaultRootfs) {
		t.Fatalf("DefaultBaseRootfs = %q", cfg.DefaultBaseRootfs)
	}
	if cfg.DefaultKernel != filepath.Join(runtimeDir, meta.DefaultKernel) {
		t.Fatalf("DefaultKernel = %q", cfg.DefaultKernel)
	}
	if cfg.DefaultInitrd != filepath.Join(runtimeDir, meta.DefaultInitrd) {
		t.Fatalf("DefaultInitrd = %q", cfg.DefaultInitrd)
	}
	if cfg.DefaultModulesDir != filepath.Join(runtimeDir, meta.DefaultModulesDir) {
		t.Fatalf("DefaultModulesDir = %q", cfg.DefaultModulesDir)
	}
	if cfg.DefaultPackagesFile != filepath.Join(runtimeDir, meta.DefaultPackages) {
		t.Fatalf("DefaultPackagesFile = %q", cfg.DefaultPackagesFile)
	}
}

func TestLoadFallsBackToLegacyRuntimeLayoutWithoutBundleMetadata(t *testing.T) {
	runtimeDir := t.TempDir()
	for _, rel := range []string{
		"firecracker",
		"id_ed25519",
		"namegen",
		"customize.sh",
		"banger-vsock-agent",
		"packages.apt",
		"rootfs-docker.ext4",
		"rootfs-docker.work-seed.ext4",
		"wtf/root/boot/vmlinux-6.8.0-94-generic",
		"wtf/root/boot/initrd.img-6.8.0-94-generic",
		"wtf/root/lib/modules/6.8.0-94-generic/modules.dep",
	} {
		path := filepath.Join(runtimeDir, rel)
		if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
			t.Fatalf("mkdir %s: %v", filepath.Dir(path), err)
		}
		if err := os.WriteFile(path, []byte("test"), 0o644); err != nil {
			t.Fatalf("write %s: %v", path, err)
		}
	}

	t.Setenv("BANGER_RUNTIME_DIR", runtimeDir)
	cfg, err := Load(paths.Layout{ConfigDir: t.TempDir()})
	if err != nil {
		t.Fatalf("Load: %v", err)
	}

	if cfg.FirecrackerBin != filepath.Join(runtimeDir, "firecracker") {
		t.Fatalf("FirecrackerBin = %q", cfg.FirecrackerBin)
	}
	if cfg.VSockAgentPath != filepath.Join(runtimeDir, "banger-vsock-agent") {
		t.Fatalf("VSockAgentPath = %q", cfg.VSockAgentPath)
	}
	if cfg.DefaultWorkSeed != filepath.Join(runtimeDir, "rootfs-docker.work-seed.ext4") {
		t.Fatalf("DefaultWorkSeed = %q", cfg.DefaultWorkSeed)
	}
	if cfg.DefaultKernel != filepath.Join(runtimeDir, "wtf/root/boot/vmlinux-6.8.0-94-generic") {
		t.Fatalf("DefaultKernel = %q", cfg.DefaultKernel)
	}
}

func TestLoadAppliesLogLevelEnvOverride(t *testing.T) {
	t.Setenv("BANGER_LOG_LEVEL", "debug")

	cfg, err := Load(paths.Layout{ConfigDir: t.TempDir()})
	if err != nil {
		t.Fatalf("Load: %v", err)
	}

	if cfg.LogLevel != "debug" {
		t.Fatalf("LogLevel = %q", cfg.LogLevel)
	}
}

func TestLoadDefaultsLogLevelToInfo(t *testing.T) {
	cfg, err := Load(paths.Layout{ConfigDir: t.TempDir()})
	if err != nil {
		t.Fatalf("Load: %v", err)
	}
	if cfg.LogLevel != "info" {
		t.Fatalf("LogLevel = %q, want info", cfg.LogLevel)
	}
}

func TestLoadIgnoresConfigSSHKeyOverrideForGuestAccess(t *testing.T) {
	runtimeDir := t.TempDir()
	meta := runtimebundle.BundleMetadata{
		FirecrackerBin:    "bin/firecracker",
		SSHKeyPath:        "keys/id_ed25519",
		NamegenPath:       "bin/namegen",
		CustomizeScript:   "scripts/customize.sh",
		VSockAgentPath:    "bin/banger-vsock-agent",
		DefaultPackages:   "config/packages.apt",
		DefaultRootfs:     "images/rootfs.ext4",
		DefaultWorkSeed:   "images/rootfs.work-seed.ext4",
		DefaultKernel:     "kernels/vmlinux",
		DefaultModulesDir: "modules/current",
	}
	for _, rel := range []string{
		meta.FirecrackerBin,
		meta.SSHKeyPath,
		meta.NamegenPath,
		meta.CustomizeScript,
		meta.VSockAgentPath,
		meta.DefaultPackages,
		meta.DefaultRootfs,
		meta.DefaultWorkSeed,
		meta.DefaultKernel,
		filepath.Join(meta.DefaultModulesDir, "modules.dep"),
	} {
		path := filepath.Join(runtimeDir, rel)
		if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
			t.Fatalf("mkdir %s: %v", filepath.Dir(path), err)
		}
		if err := os.WriteFile(path, []byte("test"), 0o644); err != nil {
			t.Fatalf("write %s: %v", path, err)
		}
	}
	data, err := json.Marshal(meta)
	if err != nil {
		t.Fatalf("Marshal: %v", err)
	}
	if err := os.WriteFile(filepath.Join(runtimeDir, runtimebundle.BundleMetadataFile), data, 0o644); err != nil {
		t.Fatalf("write bundle metadata: %v", err)
	}

	configDir := t.TempDir()
	if err := os.WriteFile(filepath.Join(configDir, "config.toml"), []byte("ssh_key_path = \"/tmp/override-key\"\n"), 0o644); err != nil {
		t.Fatalf("write config.toml: %v", err)
	}

	t.Setenv("BANGER_RUNTIME_DIR", runtimeDir)
	cfg, err := Load(paths.Layout{ConfigDir: configDir})
	if err != nil {
		t.Fatalf("Load: %v", err)
	}

	want := filepath.Join(runtimeDir, meta.SSHKeyPath)
	if cfg.SSHKeyPath != want {
		t.Fatalf("SSHKeyPath = %q, want runtime key %q", cfg.SSHKeyPath, want)
	}
}

func TestLoadAcceptsLegacyBundleVsockPingHelperPath(t *testing.T) {
	runtimeDir := t.TempDir()
	meta := runtimebundle.BundleMetadata{
		FirecrackerBin:      "bin/firecracker",
		SSHKeyPath:          "keys/id_ed25519",
		NamegenPath:         "bin/namegen",
		CustomizeScript:     "scripts/customize.sh",
		VSockPingHelperPath: "bin/banger-vsock-pingd",
		DefaultPackages:     "config/packages.apt",
		DefaultRootfs:       "images/rootfs.ext4",
		DefaultKernel:       "kernels/vmlinux",
	}
	for _, rel := range []string{
		meta.FirecrackerBin,
		meta.SSHKeyPath,
		meta.NamegenPath,
		meta.CustomizeScript,
		meta.VSockPingHelperPath,
		meta.DefaultPackages,
		meta.DefaultRootfs,
		meta.DefaultKernel,
	} {
		path := filepath.Join(runtimeDir, rel)
		if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
			t.Fatalf("mkdir %s: %v", filepath.Dir(path), err)
		}
		if err := os.WriteFile(path, []byte("test"), 0o644); err != nil {
			t.Fatalf("write %s: %v", path, err)
		}
	}
	data, err := json.Marshal(meta)
	if err != nil {
		t.Fatalf("Marshal: %v", err)
	}
	if err := os.WriteFile(filepath.Join(runtimeDir, runtimebundle.BundleMetadataFile), data, 0o644); err != nil {
		t.Fatalf("write bundle metadata: %v", err)
	}

	t.Setenv("BANGER_RUNTIME_DIR", runtimeDir)
	cfg, err := Load(paths.Layout{ConfigDir: t.TempDir()})
	if err != nil {
		t.Fatalf("Load: %v", err)
	}
	if cfg.VSockAgentPath != filepath.Join(runtimeDir, meta.VSockPingHelperPath) {
		t.Fatalf("VSockAgentPath = %q", cfg.VSockAgentPath)
	}
}

func TestLoadAcceptsLegacyConfigVsockPingHelperPath(t *testing.T) {
	configDir := t.TempDir()
	if err := os.WriteFile(filepath.Join(configDir, "config.toml"), []byte("vsock_ping_helper_path = \"/tmp/legacy-agent\"\n"), 0o644); err != nil {
		t.Fatalf("write config.toml: %v", err)
	}

	cfg, err := Load(paths.Layout{ConfigDir: configDir})
	if err != nil {
		t.Fatalf("Load: %v", err)
	}
	if cfg.VSockAgentPath != "/tmp/legacy-agent" {
		t.Fatalf("VSockAgentPath = %q", cfg.VSockAgentPath)
	}
}