package api

import (
	"archive/tar"
	"bytes"
	"net/http/httptest"
	"os"
	"path/filepath"
	"testing"
	"time"
)

func TestGenerateAndCheckETag(t *testing.T) {
	etag := generateETag(map[string]interface{}{"a": 1})
	if etag == "" {
		t.Fatal("expected non-empty etag")
	}
	req := httptest.NewRequest("GET", "/x", nil)
	req.Header.Set("If-None-Match", etag)
	if !checkETag(req, etag) {
		t.Fatal("expected etag match")
	}
}

func TestUploadSessionPhase(t *testing.T) {
	if got := uploadSessionPhase("uploading"); got != "upload" {
		t.Fatalf("unexpected phase: %q", got)
	}
	if got := uploadSessionPhase("select_blend"); got != "action_required" {
		t.Fatalf("unexpected phase: %q", got)
	}
	if got := uploadSessionPhase("something_else"); got != "processing" {
		t.Fatalf("unexpected fallback phase: %q", got)
	}
}

func TestParseTarHeader_AndTruncateString(t *testing.T) {
	var buf bytes.Buffer
	tw := tar.NewWriter(&buf)
	_ = tw.WriteHeader(&tar.Header{Name: "a.txt", Mode: 0644, Size: 3, Typeflag: tar.TypeReg})
	_, _ = tw.Write([]byte("abc"))
	_ = tw.Close()

	raw := buf.Bytes()
	if len(raw) < 512 {
		t.Fatal("tar buffer unexpectedly small")
	}
	var h tar.Header
	if err := parseTarHeader(raw[:512], &h); err != nil {
		t.Fatalf("parseTarHeader failed: %v", err)
	}
	if h.Name != "a.txt" {
		t.Fatalf("unexpected parsed name: %q", h.Name)
	}

	if got := truncateString("abcdef", 5); got != "ab..." {
		t.Fatalf("truncateString = %q, want %q", got, "ab...")
	}
}

func TestValidateUploadSessionForJobCreation_MissingSession(t *testing.T) {
	s := &Manager{
		uploadSessions: map[string]*UploadSession{},
	}
	_, _, err := s.validateUploadSessionForJobCreation("missing", 1)
	if err == nil {
		t.Fatal("expected validation error for missing session")
	}
	sessionErr, ok := err.(*uploadSessionValidationError)
	if !ok || sessionErr.Code != uploadSessionExpiredCode {
		t.Fatalf("expected %s validation error, got %#v", uploadSessionExpiredCode, err)
	}
}

func TestValidateUploadSessionForJobCreation_ContextMissing(t *testing.T) {
	tmpDir := t.TempDir()
	s := &Manager{
		uploadSessions: map[string]*UploadSession{
			"s1": {
				SessionID: "s1",
				UserID:    9,
				TempDir:   tmpDir,
				Status:    "completed",
				CreatedAt: time.Now(),
			},
		},
	}

	if _, _, err := s.validateUploadSessionForJobCreation("s1", 9); err == nil {
		t.Fatal("expected error when context.tar is missing")
	}
}

func TestValidateUploadSessionForJobCreation_NotReady(t *testing.T) {
	tmpDir := t.TempDir()
	s := &Manager{
		uploadSessions: map[string]*UploadSession{
			"s1": {
				SessionID: "s1",
				UserID:    9,
				TempDir:   tmpDir,
				Status:    "processing",
				CreatedAt: time.Now(),
			},
		},
	}

	_, _, err := s.validateUploadSessionForJobCreation("s1", 9)
	if err == nil {
		t.Fatal("expected error for session that is not completed")
	}
	sessionErr, ok := err.(*uploadSessionValidationError)
	if !ok || sessionErr.Code != uploadSessionNotReadyCode {
		t.Fatalf("expected %s validation error, got %#v", uploadSessionNotReadyCode, err)
	}
}

func TestValidateUploadSessionForJobCreation_Success(t *testing.T) {
	tmpDir := t.TempDir()
	contextPath := filepath.Join(tmpDir, "context.tar")
	if err := os.WriteFile(contextPath, []byte("tar-bytes"), 0644); err != nil {
		t.Fatalf("write context.tar: %v", err)
	}

	s := &Manager{
		uploadSessions: map[string]*UploadSession{
			"s1": {
				SessionID: "s1",
				UserID:    9,
				TempDir:   tmpDir,
				Status:    "completed",
				CreatedAt: time.Now(),
			},
		},
	}

	session, gotPath, err := s.validateUploadSessionForJobCreation("s1", 9)
	if err != nil {
		t.Fatalf("expected valid session, got error: %v", err)
	}
	if session == nil || gotPath != contextPath {
		t.Fatalf("unexpected result: session=%v path=%q", session, gotPath)
	}
}