package main

import (
	"errors"
	"os"
	"path/filepath"
	"reflect"
	"strings"
	"testing"

	"git.unkin.net/unkin/vault-tools/shared"
)

// setupVctx points XDG dirs at temp locations, writes a config file and the
// given cached tokens, and puts a fake `vault` binary on PATH. It returns the
// fake vault's absolute path.
func setupVctx(t *testing.T, cfg string, tokens map[string]shared.Token) string {
	t.Helper()
	cfgHome := t.TempDir()
	t.Setenv("XDG_CONFIG_HOME", cfgHome)
	t.Setenv("XDG_CACHE_HOME", t.TempDir())

	cfgDir := filepath.Join(cfgHome, "vault")
	if err := os.MkdirAll(cfgDir, 0o700); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(cfgDir, "vctl.yaml"), []byte(cfg), 0o600); err != nil {
		t.Fatal(err)
	}
	for name, tok := range tokens {
		tk := tok
		tk.Context = name
		if err := shared.SaveToken(&tk); err != nil {
			t.Fatal(err)
		}
	}

	binDir := t.TempDir()
	vault := filepath.Join(binDir, "vault")
	if err := os.WriteFile(vault, []byte("#!/bin/sh\nexit 0\n"), 0o755); err != nil {
		t.Fatal(err)
	}
	t.Setenv("PATH", binDir+string(os.PathListSeparator)+os.Getenv("PATH"))
	return vault
}

const vctxConfig = `
contexts:
  sydney:
    address: https://vault.syd1.au.unkin.net
  staging/sydney:
    address: https://vault-staging.syd1.au.unkin.net
    namespace: staging
`

// lastVal returns the value of the last occurrence of key in an env slice,
// mirroring exec's "last assignment wins" semantics.
func lastVal(env []string, key string) (string, bool) {
	val, ok := "", false
	for _, e := range env {
		if strings.HasPrefix(e, key+"=") {
			val, ok = e[len(key)+1:], true
		}
	}
	return val, ok
}

func TestBuildInvocationArgsAndEnvOverride(t *testing.T) {
	vault := setupVctx(t, vctxConfig, map[string]shared.Token{
		"sydney": {Address: "https://vault.syd1.au.unkin.net", Token: "s.SYDTOK"},
	})

	// Ambient VAULT_ADDR/VAULT_TOKEN must be overridden by the context's values.
	baseEnv := []string{"HOME=/home/x", "VAULT_ADDR=ambient", "VAULT_TOKEN=ambient"}
	args := []string{"kv", "get", "-field=foo", "secret/x"}

	bin, argv, env, err := buildInvocation("sydney", args, baseEnv)
	if err != nil {
		t.Fatalf("buildInvocation: %v", err)
	}
	if bin != vault {
		t.Errorf("bin = %q, want %q", bin, vault)
	}
	// argv is vault + the untouched args (vault flags like -field pass through).
	wantArgv := append([]string{vault}, args...)
	if !reflect.DeepEqual(argv, wantArgv) {
		t.Errorf("argv = %v, want %v", argv, wantArgv)
	}
	if v, _ := lastVal(env, "VAULT_ADDR"); v != "https://vault.syd1.au.unkin.net" {
		t.Errorf("VAULT_ADDR = %q, want context override to win", v)
	}
	if v, _ := lastVal(env, "VAULT_TOKEN"); v != "s.SYDTOK" {
		t.Errorf("VAULT_TOKEN = %q, want s.SYDTOK", v)
	}
	if _, ok := lastVal(env, "VAULT_NAMESPACE"); ok {
		t.Error("VAULT_NAMESPACE should be unset for a context with no namespace")
	}
	// The ambient HOME must be preserved.
	if v, _ := lastVal(env, "HOME"); v != "/home/x" {
		t.Errorf("HOME = %q, base env not preserved", v)
	}
}

func TestBuildInvocationNamespaceFromContext(t *testing.T) {
	setupVctx(t, vctxConfig, map[string]shared.Token{
		"staging/sydney": {Address: "https://vault-staging.syd1.au.unkin.net", Namespace: "staging", Token: "s.X"},
	})
	_, _, env, err := buildInvocation("staging/sydney", []string{"token", "lookup"}, nil)
	if err != nil {
		t.Fatalf("buildInvocation: %v", err)
	}
	if v, _ := lastVal(env, "VAULT_NAMESPACE"); v != "staging" {
		t.Errorf("VAULT_NAMESPACE = %q, want staging", v)
	}
}

func TestBuildInvocationNamespaceFallsBackToToken(t *testing.T) {
	// Context has no namespace, but the cached token records one — vctx should
	// fall back to the token's namespace.
	setupVctx(t, vctxConfig, map[string]shared.Token{
		"sydney": {Address: "https://vault.syd1.au.unkin.net", Namespace: "from-token", Token: "s.X"},
	})
	_, _, env, err := buildInvocation("sydney", []string{"status"}, nil)
	if err != nil {
		t.Fatalf("buildInvocation: %v", err)
	}
	if v, _ := lastVal(env, "VAULT_NAMESPACE"); v != "from-token" {
		t.Errorf("VAULT_NAMESPACE = %q, want from-token fallback", v)
	}
}

func TestBuildInvocationMissingToken(t *testing.T) {
	setupVctx(t, vctxConfig, nil) // no cached tokens
	_, _, _, err := buildInvocation("sydney", []string{"status"}, nil)
	if err == nil {
		t.Fatal("expected error for missing cached token")
	}
	if !errors.Is(err, os.ErrNotExist) {
		t.Errorf("error should wrap os.ErrNotExist, got %v", err)
	}
}

func TestBuildInvocationUnknownContext(t *testing.T) {
	setupVctx(t, vctxConfig, nil)
	if _, _, _, err := buildInvocation("nope", []string{"status"}, nil); err == nil {
		t.Error("expected error for unknown context")
	}
}

func TestRunVctxValidation(t *testing.T) {
	if err := runVctx("", []string{"status"}); err == nil || !strings.Contains(err.Error(), "--context is required") {
		t.Errorf("empty context: got %v", err)
	}
	if err := runVctx("sydney", nil); err == nil || !strings.Contains(err.Error(), "no vault arguments") {
		t.Errorf("no args: got %v", err)
	}
}

func TestRunVctxExecsWithBuiltInvocation(t *testing.T) {
	vault := setupVctx(t, vctxConfig, map[string]shared.Token{
		"sydney": {Address: "https://vault.syd1.au.unkin.net", Token: "s.SYDTOK"},
	})

	var gotBin string
	var gotArgv, gotEnv []string
	orig := execVault
	execVault = func(bin string, argv, env []string) error {
		gotBin, gotArgv, gotEnv = bin, argv, env
		return nil
	}
	t.Cleanup(func() { execVault = orig })

	if err := runVctx("sydney", []string{"kv", "list", "kv/"}); err != nil {
		t.Fatalf("runVctx: %v", err)
	}
	if gotBin != vault {
		t.Errorf("exec bin = %q, want %q", gotBin, vault)
	}
	if !reflect.DeepEqual(gotArgv, []string{vault, "kv", "list", "kv/"}) {
		t.Errorf("exec argv = %v", gotArgv)
	}
	if v, _ := lastVal(gotEnv, "VAULT_TOKEN"); v != "s.SYDTOK" {
		t.Errorf("exec env VAULT_TOKEN = %q", v)
	}
}

func TestRunVctxSurfacesExecError(t *testing.T) {
	setupVctx(t, vctxConfig, map[string]shared.Token{
		"sydney": {Address: "https://vault.syd1.au.unkin.net", Token: "s.X"},
	})
	orig := execVault
	execVault = func(bin string, argv, env []string) error { return errors.New("boom") }
	t.Cleanup(func() { execVault = orig })

	err := runVctx("sydney", []string{"status"})
	if err == nil || !strings.Contains(err.Error(), "exec vault") {
		t.Errorf("expected wrapped exec error, got %v", err)
	}
}