package receiver

import (
	"strconv"
	"strings"
	"testing"
	"time"
)

func TestGenerateToken_Format(t *testing.T) {
	token := GenerateToken("key", "org", "repo", "wf", "job")
	parts := strings.SplitN(token, ":", 2)
	if len(parts) != 2 {
		t.Fatalf("token should have format 'timestamp:hmac', got %q", token)
	}
	if len(parts[1]) != 64 {
		t.Errorf("HMAC part length = %d, want 64", len(parts[1]))
	}
}

func TestGenerateTokenAt_Deterministic(t *testing.T) {
	ts := time.Unix(1700000000, 0)
	token1 := GenerateTokenAt("key", "org", "repo", "wf", "job", ts)
	token2 := GenerateTokenAt("key", "org", "repo", "wf", "job", ts)
	if token1 != token2 {
		t.Errorf("tokens differ: %q vs %q", token1, token2)
	}
}

func TestGenerateTokenAt_ScopePinning(t *testing.T) {
	ts := time.Unix(1700000000, 0)
	base := GenerateTokenAt("key", "org", "repo", "wf", "job", ts)

	variants := []struct {
		name string
		org  string
		repo string
		wf   string
		job  string
	}{
		{"different org", "other-org", "repo", "wf", "job"},
		{"different repo", "org", "other-repo", "wf", "job"},
		{"different workflow", "org", "repo", "other-wf", "job"},
		{"different job", "org", "repo", "wf", "other-job"},
	}

	for _, v := range variants {
		t.Run(v.name, func(t *testing.T) {
			token := GenerateTokenAt("key", v.org, v.repo, v.wf, v.job, ts)
			if token == base {
				t.Errorf("token for %s should differ from base", v.name)
			}
		})
	}
}

func TestGenerateTokenAt_DifferentKeys(t *testing.T) {
	ts := time.Unix(1700000000, 0)
	token1 := GenerateTokenAt("key-a", "org", "repo", "wf", "job", ts)
	token2 := GenerateTokenAt("key-b", "org", "repo", "wf", "job", ts)
	if token1 == token2 {
		t.Error("different keys should produce different tokens")
	}
}

func TestGenerateTokenAt_DifferentTimestamps(t *testing.T) {
	ts1 := time.Unix(1700000000, 0)
	ts2 := time.Unix(1700000001, 0)
	token1 := GenerateTokenAt("key", "org", "repo", "wf", "job", ts1)
	token2 := GenerateTokenAt("key", "org", "repo", "wf", "job", ts2)
	if token1 == token2 {
		t.Error("different timestamps should produce different tokens")
	}
}

func TestValidateToken_Correct(t *testing.T) {
	ts := time.Now()
	token := GenerateTokenAt("key", "org", "repo", "wf", "job", ts)
	if !ValidateToken("key", token, "org", "repo", "wf", "job", 5*time.Minute) {
		t.Error("ValidateToken should accept correct token")
	}
}

func TestValidateToken_WrongToken(t *testing.T) {
	if ValidateToken("key", "12345:deadbeef", "org", "repo", "wf", "job", 5*time.Minute) {
		t.Error("ValidateToken should reject wrong token")
	}
}

func TestValidateToken_WrongScope(t *testing.T) {
	ts := time.Now()
	token := GenerateTokenAt("key", "org", "repo", "wf", "job", ts)
	if ValidateToken("key", token, "org", "repo", "wf", "other-job", 5*time.Minute) {
		t.Error("ValidateToken should reject token for different scope")
	}
}

func TestValidateToken_Expired(t *testing.T) {
	ts := time.Now().Add(-10 * time.Minute)
	token := GenerateTokenAt("key", "org", "repo", "wf", "job", ts)
	if ValidateToken("key", token, "org", "repo", "wf", "job", 5*time.Minute) {
		t.Error("ValidateToken should reject expired token")
	}
}

func TestValidateTokenAt_NotExpired(t *testing.T) {
	tokenTime := time.Unix(1700000000, 0)
	token := GenerateTokenAt("key", "org", "repo", "wf", "job", tokenTime)

	// Validate at 4 minutes later (within 5 minute TTL)
	now := tokenTime.Add(4 * time.Minute)
	if !ValidateTokenAt("key", token, "org", "repo", "wf", "job", 5*time.Minute, now) {
		t.Error("ValidateTokenAt should accept token within TTL")
	}
}

func TestValidateTokenAt_JustExpired(t *testing.T) {
	tokenTime := time.Unix(1700000000, 0)
	token := GenerateTokenAt("key", "org", "repo", "wf", "job", tokenTime)

	// Validate at 6 minutes later (beyond 5 minute TTL)
	now := tokenTime.Add(6 * time.Minute)
	if ValidateTokenAt("key", token, "org", "repo", "wf", "job", 5*time.Minute, now) {
		t.Error("ValidateTokenAt should reject token beyond TTL")
	}
}

func TestValidateToken_InvalidFormat(t *testing.T) {
	if ValidateToken("key", "no-colon-here", "org", "repo", "wf", "job", 5*time.Minute) {
		t.Error("ValidateToken should reject token without colon")
	}
	if ValidateToken("key", "not-a-number:abc123", "org", "repo", "wf", "job", 5*time.Minute) {
		t.Error("ValidateToken should reject token with invalid timestamp")
	}
}

func TestParseTokenTimestamp(t *testing.T) {
	ts := time.Unix(1700000000, 0)
	token := GenerateTokenAt("key", "org", "repo", "wf", "job", ts)

	parsed, err := ParseTokenTimestamp(token)
	if err != nil {
		t.Fatalf("ParseTokenTimestamp failed: %v", err)
	}
	if !parsed.Equal(ts) {
		t.Errorf("parsed timestamp = %v, want %v", parsed, ts)
	}
}

func TestParseTokenTimestamp_Invalid(t *testing.T) {
	_, err := ParseTokenTimestamp("no-colon")
	if err == nil {
		t.Error("ParseTokenTimestamp should fail on missing colon")
	}

	_, err = ParseTokenTimestamp("not-a-number:abc123")
	if err == nil {
		t.Error("ParseTokenTimestamp should fail on invalid timestamp")
	}
}

func TestValidateToken_TamperedTimestamp(t *testing.T) {
	// Generate a valid token
	ts := time.Now()
	token := GenerateTokenAt("key", "org", "repo", "wf", "job", ts)

	parts := strings.SplitN(token, ":", 2)
	if len(parts) != 2 {
		t.Fatalf("unexpected token format: %q", token)
	}
	hmacPart := parts[1]

	// Tamper with timestamp (e.g., attacker tries to extend token lifetime)
	tamperedTimestamp := strconv.FormatInt(time.Now().Add(1*time.Hour).Unix(), 10)
	tamperedToken := tamperedTimestamp + ":" + hmacPart

	if ValidateToken("key", tamperedToken, "org", "repo", "wf", "job", 5*time.Minute) {
		t.Error("ValidateToken should reject token with tampered timestamp")
	}
}