import XCTest
@testable import AIStudyApp

final class ReadingAPIClientTests: XCTestCase {

    // MARK: - Batch response decoding

    func test_batch_response_decodes_all_fields() throws {
        let json = """
        {
            "processed": 5,
            "duplicate": 2,
            "failed": 1,
            "warnings": [
                {"eventId": "evt-001", "code": "DUPLICATE_EVENT", "message": "already processed"}
            ]
        }
        """.data(using: .utf8)!

        let resp = try JSONDecoder().decode(ReadingEventBatchResponse.self, from: json)
        XCTAssertEqual(resp.processed, 5)
        XCTAssertEqual(resp.duplicate, 2)
        XCTAssertEqual(resp.failed, 1)
        XCTAssertEqual(resp.warnings?.count, 1)
    }

    func test_batch_response_no_warnings() throws {
        let json = """
        {
            "processed": 3,
            "duplicate": 0,
            "failed": 0
        }
        """.data(using: .utf8)!

        let resp = try JSONDecoder().decode(ReadingEventBatchResponse.self, from: json)
        XCTAssertEqual(resp.processed, 3)
        XCTAssertNil(resp.warnings)
    }

    func test_batch_response_duplicate_not_counted_as_failed() throws {
        let json = """
        {
            "processed": 1,
            "duplicate": 5,
            "failed": 0
        }
        """.data(using: .utf8)!

        let resp = try JSONDecoder().decode(ReadingEventBatchResponse.self, from: json)
        // Duplicate should not count as failed
        XCTAssertEqual(resp.failed, 0)
        XCTAssertEqual(resp.duplicate, 5)
    }

    // MARK: - API service existence

    func test_api_service_shared_exists() {
        let api = ReadingAPIService.shared
        XCTAssertNotNil(api)
    }

    // MARK: - Other response DTOs

    func test_material_reading_progress_decodes() throws {
        let json = """
        {
            "status": "reading",
            "lastProgress": 0.65,
            "totalActiveSeconds": 1200,
            "isMarkedRead": false,
            "firstOpenedAt": "2026-01-01T00:00:00Z",
            "lastReadAt": "2026-06-12T00:00:00Z"
        }
        """.data(using: .utf8)!

        let dto = try JSONDecoder().decode(MaterialReadingProgressDTO.self, from: json)
        XCTAssertEqual(dto.status, "reading")
        XCTAssertEqual(dto.totalActiveSeconds, 1200)
        XCTAssertFalse(dto.isMarkedRead)
    }

    func test_continue_learning_response_decodes() throws {
        let json = """
        {
            "type": "knowledge_source",
            "materialId": "mat-001",
            "title": "Rust Book",
            "lastProgress": 0.4,
            "totalActiveSeconds": 600,
            "lastReadAt": "2026-06-12T00:00:00Z"
        }
        """.data(using: .utf8)!

        let dto = try JSONDecoder().decode(ContinueLearningResponse.self, from: json)
        XCTAssertEqual(dto.type, "knowledge_source")
        XCTAssertEqual(dto.materialId, "mat-001")
    }

    func test_continue_learning_response_none_type() throws {
        let json = """
        {
            "type": "none",
            "materialId": null,
            "title": null,
            "lastProgress": null,
            "totalActiveSeconds": null,
            "lastReadAt": null
        }
        """.data(using: .utf8)!

        let dto = try JSONDecoder().decode(ContinueLearningResponse.self, from: json)
        XCTAssertEqual(dto.type, "none")
        XCTAssertNil(dto.materialId)
    }

    func test_learning_summary_decodes() throws {
        let json = """
        {
            "todaySeconds": 300,
            "weekSeconds": 2100,
            "totalSeconds": 50000,
            "activeDays": 45,
            "sessionsCount": 120,
            "materialsReadCount": 15,
            "markedReadCount": 8,
            "dailyAverageSeconds": 1100
        }
        """.data(using: .utf8)!

        let dto = try JSONDecoder().decode(LearningSummaryResponse.self, from: json)
        XCTAssertEqual(dto.todaySeconds, 300)
        XCTAssertEqual(dto.materialsReadCount, 15)
    }
}