@testable import ForgejoKit
import Foundation
import Testing

struct NotificationTests {
    private func decoder() -> JSONDecoder {
        let jsonDecoder = JSONDecoder()
        jsonDecoder.dateDecodingStrategy = forgejoDateDecodingStrategy
        return jsonDecoder
    }

    // MARK: - Subject number extraction

    @Test func extractsIssueNumberFromSubjectUrl() {
        let url = "https://forgejo.example.com/api/v1/repos/org/app/issues/42"
        #expect(notificationSubjectNumber(from: url) == 42)
    }

    @Test func extractsPullRequestNumberFromSubjectUrl() {
        let url = "https://forgejo.example.com/api/v1/repos/user/repo/pulls/7"
        #expect(notificationSubjectNumber(from: url) == 7)
    }

    @Test func returnsNilForNilUrl() {
        #expect(notificationSubjectNumber(from: nil) == nil)
    }

    @Test func returnsNilForNonNumericLastComponent() {
        let url = "https://forgejo.example.com/api/v1/repos/org/app/commits/abc123"
        #expect(notificationSubjectNumber(from: url) == nil)
    }

    @Test func returnsNilForEmptyString() {
        #expect(notificationSubjectNumber(from: "") == nil)
    }

    @Test func returnsNilForInvalidUrl() {
        #expect(notificationSubjectNumber(from: "not a url at all %%%") == nil)
    }

    @Test func extractsNumberFromUrlWithTrailingSlash() {
        let url = "https://forgejo.example.com/api/v1/repos/org/app/issues/42/"
        #expect(notificationSubjectNumber(from: url) == 42)
    }

    @Test func extractsLargeNumber() {
        let url = "https://forgejo.example.com/api/v1/repos/org/app/issues/99999"
        #expect(notificationSubjectNumber(from: url) == 99999)
    }

    @Test func extractsNumberFromUrlWithQueryParams() {
        let url = "https://forgejo.example.com/api/v1/repos/org/app/issues/42?foo=bar&baz=1"
        #expect(notificationSubjectNumber(from: url) == 42)
    }

    @Test func extractsNumberFromUrlWithFragment() {
        let url = "https://forgejo.example.com/api/v1/repos/org/app/pulls/7#section"
        #expect(notificationSubjectNumber(from: url) == 7)
    }

    @Test func extractsNumberFromUrlWithQueryAndFragment() {
        let url = "https://forgejo.example.com/api/v1/repos/org/app/issues/15?ref=main#comment-1"
        #expect(notificationSubjectNumber(from: url) == 15)
    }

    // MARK: - Full API response decoding

    @Test func decodesNotificationArray() throws {
        let json = """
        [
            {
                "id": 1,
                "unread": true,
                "pinned": false,
                "updated_at": "2024-06-15T14:30:00Z",
                "subject": {
                    "type": "Issue",
                    "title": "Bug report",
                    "url": "https://forgejo.example.com/api/v1/repos/org/app/issues/1",
                    "state": "open"
                },
                "repository": {"id": 10, "name": "app", "full_name": "org/app"}
            },
            {
                "id": 2,
                "unread": false,
                "pinned": true,
                "updated_at": "2024-06-14T10:00:00Z",
                "subject": {
                    "type": "Pull",
                    "title": "Add feature",
                    "url": "https://forgejo.example.com/api/v1/repos/org/app/pulls/5",
                    "state": "closed"
                },
                "repository": {"id": 10, "name": "app", "full_name": "org/app"}
            }
        ]
        """
        let notifications = try decoder().decode([NotificationThread].self, from: Data(json.utf8))
        #expect(notifications.count == 2)
        #expect(notifications[0].id == 1)
        #expect(notifications[0].unread == true)
        #expect(notifications[0].subject.type == "Issue")
        #expect(notifications[1].id == 2)
        #expect(notifications[1].pinned == true)
        #expect(notifications[1].subject.type == "Pull")
    }

    @Test func decodesEmptyNotificationArray() throws {
        let json = "[]"
        let notifications = try decoder().decode([NotificationThread].self, from: Data(json.utf8))
        #expect(notifications.isEmpty)
    }

    @Test func decodesNotificationCountZero() throws {
        let json = #"{"new": 0}"#
        let count = try decoder().decode(NotificationCount.self, from: Data(json.utf8))
        #expect(count.new == 0)
    }

    @Test func decodesNotificationCountLargeValue() throws {
        let json = #"{"new": 9999}"#
        let count = try decoder().decode(NotificationCount.self, from: Data(json.utf8))
        #expect(count.new == 9999)
    }

    // MARK: - Date handling in notifications

    @Test func decodesNotificationWithFractionalSecondsDate() throws {
        let json = """
        {
            "id": 5,
            "unread": true,
            "pinned": false,
            "updated_at": "2024-06-15T14:30:00.123Z",
            "subject": {"type": "Issue", "title": "Test"},
            "repository": {"id": 1, "name": "r", "full_name": "u/r"}
        }
        """
        let notification = try decoder().decode(NotificationThread.self, from: Data(json.utf8))
        #expect(notification.id == 5)
        #expect(notification.updatedAt.timeIntervalSince1970 > 0)
    }

    // MARK: - Extra/unknown fields are ignored

    @Test func decodesNotificationIgnoringExtraFields() throws {
        let json = """
        {
            "id": 6,
            "unread": true,
            "pinned": false,
            "updated_at": "2024-06-15T14:30:00Z",
            "some_future_field": "should be ignored",
            "subject": {
                "type": "Issue",
                "title": "Test",
                "some_other_field": 42
            },
            "repository": {"id": 1, "name": "r", "full_name": "u/r", "extra": true}
        }
        """
        let notification = try decoder().decode(NotificationThread.self, from: Data(json.utf8))
        #expect(notification.id == 6)
        #expect(notification.subject.title == "Test")
    }

    // MARK: - Required fields validation

    @Test func failsDecodingNotificationMissingSubject() {
        let json = """
        {
            "id": 7,
            "unread": true,
            "pinned": false,
            "updated_at": "2024-06-15T14:30:00Z",
            "repository": {"id": 1, "name": "r", "full_name": "u/r"}
        }
        """
        #expect(throws: DecodingError.self) {
            _ = try decoder().decode(NotificationThread.self, from: Data(json.utf8))
        }
    }

    @Test func failsDecodingNotificationMissingRepository() {
        let json = """
        {
            "id": 8,
            "unread": true,
            "pinned": false,
            "updated_at": "2024-06-15T14:30:00Z",
            "subject": {"type": "Issue", "title": "Test"}
        }
        """
        #expect(throws: DecodingError.self) {
            _ = try decoder().decode(NotificationThread.self, from: Data(json.utf8))
        }
    }

    @Test func failsDecodingNotificationMissingId() {
        let json = """
        {
            "unread": true,
            "pinned": false,
            "updated_at": "2024-06-15T14:30:00Z",
            "subject": {"type": "Issue", "title": "Test"},
            "repository": {"id": 1, "name": "r", "full_name": "u/r"}
        }
        """
        #expect(throws: DecodingError.self) {
            _ = try decoder().decode(NotificationThread.self, from: Data(json.utf8))
        }
    }

    @Test func failsDecodingNotificationCountMissingNewField() {
        let json = #"{}"#
        #expect(throws: DecodingError.self) {
            _ = try decoder().decode(NotificationCount.self, from: Data(json.utf8))
        }
    }

    @Test func failsDecodingSubjectMissingTitle() {
        let json = """
        {
            "id": 9,
            "unread": true,
            "pinned": false,
            "updated_at": "2024-06-15T14:30:00Z",
            "subject": {"type": "Issue"},
            "repository": {"id": 1, "name": "r", "full_name": "u/r"}
        }
        """
        #expect(throws: DecodingError.self) {
            _ = try decoder().decode(NotificationThread.self, from: Data(json.utf8))
        }
    }
}