using System.Security.Claims;
using System.Text;
using System.Text.Json;
using JobTrackerApi.Controllers;
using JobTrackerApi.Models;
using JobTrackerApi.Services;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Options;
using Moq;
using Xunit;

namespace JobTrackerApi.Tests;

public sealed class ProfileCvControllerTests
{
    [Fact]
    public async Task Upload_rejects_unsupported_extension()
    {
        var user = new ApplicationUser();
        var userManager = CreateUserManager();
        userManager.Setup(x => x.GetUserAsync(It.IsAny<ClaimsPrincipal>())).ReturnsAsync(user);
        var aiService = new Mock<ISummarizerService>();

        var controller = new ProfileCvController(userManager.Object, aiService.Object)
        {
            ControllerContext = new ControllerContext { HttpContext = new DefaultHttpContext() }
        };

        var file = new FormFile(new MemoryStream(Encoding.UTF8.GetBytes("hello")), 0, 5, "file", "resume.exe");
        var result = await controller.Upload(file);

        var badRequest = Assert.IsType<BadRequestObjectResult>(result);
        Assert.True((badRequest.Value?.ToString() ?? string.Empty).Contains("supported", StringComparison.OrdinalIgnoreCase));
    }

    [Fact]
    public async Task Upload_reconstructs_flattened_pdf_cv_before_save()
    {
        var rawExtraction = "connor.babbington@cesnimda.co.uk cesnimda.co.uk +47 41 33 44 70 E D U C A T I O N E X T E N D E D D I P L O M A N V Q L E V E L 3 I N I C T 2012 - 2015 F O L L O W A B O U T M E Mid-level system developer with eight years of experience in UK local government. I N T E R E S T S E X P E R I E N C E S Y S T E M D E V E L O P E R 2015 - 2023 Developed and maintained multiple full-stack applications using C#, Python, Ruby on Rails, SQL, and JavaScript. + Warwickshire County Council, UK C O N T A C T Native English speaker, Norwegian level A2/B1.";
        var reconstructed = "# Connor Babbington\n\n## Contact\nconnor.babbington@cesnimda.co.uk\ncesnimda.co.uk\n+47 41 33 44 70\nTønsberg, Norway\n\n## Professional Summary\nMid-level system developer with eight years of experience in UK local government.\n\n## Work Experience\n### System Developer\nWarwickshire County Council\nUK\n2015 - 2023\n- Developed and maintained multiple full-stack applications using C#, Python, Ruby on Rails, SQL, and JavaScript.\n\n## Education\n### Extended Diploma NVQ Level 3 in ICT\nWarwickshire College\n2012 - 2015\n\n## Languages\nEnglish: Native\nNorwegian: A2/B1";
        var structuredJson = """
        {
          "version": "1",
          "contact": {
            "fullName": "Connor Babbington",
            "email": "connor.babbington@cesnimda.co.uk",
            "phone": "+47 41 33 44 70",
            "location": "Tønsberg, Norway",
            "website": "cesnimda.co.uk"
          },
          "summary": ["Mid-level system developer with eight years of experience in UK local government."],
          "jobs": [
            {
              "title": "System Developer",
              "company": "Warwickshire County Council",
              "location": "UK",
              "start": "2015",
              "end": "2023",
              "isCurrent": false,
              "bullets": ["Developed and maintained multiple full-stack applications using C#, Python, Ruby on Rails, SQL, and JavaScript."],
              "skills": ["C#", "Python", "Ruby on Rails", "SQL", "JavaScript"]
            }
          ],
          "education": [
            {
              "qualification": "Extended Diploma NVQ Level 3 in ICT",
              "institution": "Warwickshire College",
              "start": "2012",
              "end": "2015",
              "details": []
            }
          ],
          "skills": ["C#", "Python", "Ruby on Rails", "SQL", "JavaScript"],
          "languages": [
            { "name": "English", "level": "Native" },
            { "name": "Norwegian", "level": "A2/B1" }
          ],
          "interests": [],
          "otherSections": []
        }
        """;

        var user = new ApplicationUser();
        var userManager = CreateUserManager();
        userManager.Setup(x => x.GetUserAsync(It.IsAny<ClaimsPrincipal>())).ReturnsAsync(user);
        userManager.Setup(x => x.UpdateAsync(user)).ReturnsAsync(IdentityResult.Success);
        var aiService = new Mock<ISummarizerService>();
        aiService
            .Setup(x => x.ExtractTextAsync(It.IsAny<Stream>(), It.IsAny<string>(), It.IsAny<string?>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new AiTextExtractionResult(rawExtraction, false, "application/pdf", 1, rawExtraction.Length, "Resume.en.pdf"));
        aiService
            .Setup(x => x.SummarizeSectionAsync(It.Is<string>(instruction => instruction.Contains("Reconstruct this CV text extracted from a PDF", StringComparison.Ordinal)), rawExtraction, 2800, 900))
            .ReturnsAsync(reconstructed);
        aiService
            .Setup(x => x.SummarizeSectionAsync(It.Is<string>(instruction => instruction.Contains("Extract this CV into structured JSON", StringComparison.Ordinal)), reconstructed, 3200, 900))
            .ReturnsAsync(structuredJson);

        var controller = new ProfileCvController(userManager.Object, aiService.Object)
        {
            ControllerContext = new ControllerContext { HttpContext = new DefaultHttpContext() }
        };

        var bytes = Encoding.UTF8.GetBytes("fake pdf bytes");
        var file = new FormFile(new MemoryStream(bytes), 0, bytes.Length, "file", "Resume.en.pdf")
        {
            Headers = new HeaderDictionary(),
            ContentType = "application/pdf"
        };

        var result = await controller.Upload(file);

        Assert.IsType<OkObjectResult>(result);
        Assert.Equal(reconstructed, user.ProfileCvText);

        var structured = StructuredCvProfileJson.Deserialize(user.ProfileCvStructureJson);
        Assert.Equal("Connor Babbington", structured.Contact.FullName);
        Assert.Single(structured.Summary);
        Assert.Single(structured.Jobs);
        Assert.Equal("System Developer", structured.Jobs[0].Title);
        Assert.Single(structured.Education);
        Assert.Equal("Extended Diploma NVQ Level 3 in ICT", structured.Education[0].Qualification);
        Assert.Contains(structured.Sections, section => section.Name == "Contact");
        Assert.Contains(structured.Sections, section => section.Name == "Professional Summary");
        Assert.Contains(structured.Sections, section => section.Name == "Work Experience");
        Assert.Contains(structured.Sections, section => section.Name == "Education");
    }

    [Fact]
    public async Task Upload_populates_structured_fields_from_flattened_cv_when_ai_json_is_invalid()
    {
        var rawExtraction = "connor.babbington@cesnimda.co.uk cesnimda.co.uk +47 41 33 44 70 E D U C A T I O N E X T E N D E D D I P L O M A N V Q L E V E L 3 I N I C T 2012 - 2015 F O L L O W A B O U T M E Mid-level system developer with eight years of experience in UK local government, with expertise in full-stack development, backend, frontend and server administration. I N T E R E S T S I am interested in PC and board games, as well as cooking and learning new skills. E X P E R I E N C E S Y S T E M D E V E L O P E R 2015 - 2023 Developed and maintained multiple full-stack applications using C#, Python, Ruby on Rails, SQL, and JavaScript. + Warwickshire County Council, UK C O N T A C T Native English speaker, Norwegian level A2/B1.";

        var user = new ApplicationUser();
        var userManager = CreateUserManager();
        userManager.Setup(x => x.GetUserAsync(It.IsAny<ClaimsPrincipal>())).ReturnsAsync(user);
        userManager.Setup(x => x.UpdateAsync(user)).ReturnsAsync(IdentityResult.Success);
        var aiService = new Mock<ISummarizerService>();
        aiService
            .Setup(x => x.ExtractTextAsync(It.IsAny<Stream>(), It.IsAny<string>(), It.IsAny<string?>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new AiTextExtractionResult(rawExtraction, false, "application/pdf", 1, rawExtraction.Length, "Resume.en.pdf"));
        aiService
            .Setup(x => x.SummarizeSectionAsync(It.Is<string>(instruction => instruction.Contains("Reconstruct this CV text extracted from a PDF", StringComparison.Ordinal)), rawExtraction, 2800, 900))
            .ReturnsAsync(string.Empty);
        aiService
            .Setup(x => x.SummarizeSectionAsync(It.Is<string>(instruction => instruction.Contains("Extract this CV into structured JSON", StringComparison.Ordinal)), It.IsAny<string>(), 3200, 900))
            .ReturnsAsync("not-json");

        var controller = new ProfileCvController(userManager.Object, aiService.Object)
        {
            ControllerContext = new ControllerContext { HttpContext = new DefaultHttpContext() }
        };

        var bytes = Encoding.UTF8.GetBytes("fake pdf bytes");
        var file = new FormFile(new MemoryStream(bytes), 0, bytes.Length, "file", "Resume.en.pdf")
        {
            Headers = new HeaderDictionary(),
            ContentType = "application/pdf"
        };

        var result = await controller.Upload(file);

        Assert.IsType<OkObjectResult>(result);
        var structured = StructuredCvProfileJson.Deserialize(user.ProfileCvStructureJson);
        Assert.Equal("Connor Babbington", structured.Contact.FullName);
        Assert.Equal("connor.babbington@cesnimda.co.uk", structured.Contact.Email);
        Assert.Equal("+47 41 33 44 70", structured.Contact.Phone);
        Assert.Contains(structured.Summary, item => item.Contains("eight years of experience", StringComparison.OrdinalIgnoreCase));
        Assert.Contains(structured.Skills, item => item.Equals("C#", StringComparison.OrdinalIgnoreCase));
        Assert.Contains(structured.Interests, item => item.Contains("board games", StringComparison.OrdinalIgnoreCase) || item.Contains("cooking", StringComparison.OrdinalIgnoreCase));
        Assert.Contains(structured.Languages, item => item.Name != null && item.Name.Equals("English", StringComparison.OrdinalIgnoreCase));
        Assert.Contains(structured.Languages, item => item.Name != null && item.Name.StartsWith("Norwegian", StringComparison.OrdinalIgnoreCase));
        Assert.DoesNotContain(structured.Sections, section => section.Name == "General");
    }

    [Fact]
    public async Task Parse_returns_structured_cv_and_persists_it()
    {
        var user = new ApplicationUser
        {
            ProfileCvText = "# Connor Babbington\n\n## Contact\nconnor@example.com\n+47 41 33 44 70\n\n## Professional Summary\nBuilt backend systems.\n\n## Work Experience\n### System Developer\nWarwickshire County Council\n2015 - 2023\n- Built APIs\n\n## Education\n### Warwickshire College\n2012 - 2015"
        };
        var structuredJson = """
        {
          "version": "1",
          "contact": {
            "fullName": "Connor Babbington",
            "email": "connor@example.com",
            "phone": "+47 41 33 44 70"
          },
          "summary": ["Built backend systems."],
          "jobs": [
            {
              "title": "System Developer",
              "company": "Warwickshire County Council",
              "start": "2015",
              "end": "2023",
              "isCurrent": false,
              "bullets": ["Built APIs"],
              "skills": [".NET"]
            }
          ],
          "education": [
            {
              "qualification": "Warwickshire College",
              "start": "2012",
              "end": "2015",
              "details": []
            }
          ],
          "skills": [".NET"],
          "languages": [],
          "interests": [],
          "otherSections": []
        }
        """;

        var userManager = CreateUserManager();
        userManager.Setup(x => x.GetUserAsync(It.IsAny<ClaimsPrincipal>())).ReturnsAsync(user);
        userManager.Setup(x => x.UpdateAsync(user)).ReturnsAsync(IdentityResult.Success);
        var aiService = new Mock<ISummarizerService>();
        aiService
            .Setup(x => x.SummarizeSectionAsync(It.Is<string>(instruction => instruction.Contains("Extract this CV into structured JSON", StringComparison.Ordinal)), user.ProfileCvText, 3200, 900))
            .ReturnsAsync(structuredJson);

        var controller = new ProfileCvController(userManager.Object, aiService.Object)
        {
            ControllerContext = new ControllerContext { HttpContext = new DefaultHttpContext() }
        };

        var result = await controller.Parse(new ProfileCvController.ParseCvRequest(user.ProfileCvText));

        var ok = Assert.IsType<OkObjectResult>(result.Result);
        var json = JsonSerializer.Serialize(ok.Value);
        Assert.Contains("structuredCv", json, StringComparison.OrdinalIgnoreCase);
        Assert.Contains("Connor Babbington", json);
        Assert.Contains("System Developer", json);

        var structured = StructuredCvProfileJson.Deserialize(user.ProfileCvStructureJson);
        Assert.Equal("Connor Babbington", structured.Contact.FullName);
        Assert.Single(structured.Jobs);
        Assert.Equal("System Developer", structured.Jobs[0].Title);
    }

    [Fact]
    public async Task Parse_falls_back_to_section_parsing_when_ai_json_is_invalid()
    {
        var user = new ApplicationUser
        {
            ProfileCvText = "# Connor Babbington\n\n## Professional Summary\nBuilt backend systems.\n\n## Skills\n.NET\nSQL\nAzure"
        };
        var userManager = CreateUserManager();
        userManager.Setup(x => x.GetUserAsync(It.IsAny<ClaimsPrincipal>())).ReturnsAsync(user);
        userManager.Setup(x => x.UpdateAsync(user)).ReturnsAsync(IdentityResult.Success);
        var aiService = new Mock<ISummarizerService>();
        aiService
            .Setup(x => x.SummarizeSectionAsync(It.Is<string>(instruction => instruction.Contains("Extract this CV into structured JSON", StringComparison.Ordinal)), user.ProfileCvText, 3200, 900))
            .ReturnsAsync("not-json");

        var controller = new ProfileCvController(userManager.Object, aiService.Object)
        {
            ControllerContext = new ControllerContext { HttpContext = new DefaultHttpContext() }
        };

        var result = await controller.Parse(new ProfileCvController.ParseCvRequest(user.ProfileCvText));

        var ok = Assert.IsType<OkObjectResult>(result.Result);
        var json = JsonSerializer.Serialize(ok.Value);
        Assert.Contains("Professional Summary", json);

        var structured = StructuredCvProfileJson.Deserialize(user.ProfileCvStructureJson);
        Assert.Contains("Built backend systems.", structured.Summary);
        Assert.Contains(".NET", structured.Skills);
        Assert.Contains("SQL", structured.Skills);
        Assert.Equal("Connor Babbington", structured.Contact.FullName);
    }

    [Fact]
    public async Task Upload_accepts_markdown_cv_and_saves_text()
    {
        var user = new ApplicationUser();
        var userManager = CreateUserManager();
        userManager.Setup(x => x.GetUserAsync(It.IsAny<ClaimsPrincipal>())).ReturnsAsync(user);
        userManager.Setup(x => x.UpdateAsync(user)).ReturnsAsync(IdentityResult.Success);
        var aiService = new Mock<ISummarizerService>();
        aiService
            .Setup(x => x.ExtractTextAsync(It.IsAny<Stream>(), It.IsAny<string>(), It.IsAny<string?>(), It.IsAny<CancellationToken>()))
            .ReturnsAsync(new AiTextExtractionResult("# Connor Babbington\n\n## Professional Summary\nBuilt APIs and UIs", false, "text/markdown", null, 62, "resume.md"));
        aiService
            .Setup(x => x.SummarizeSectionAsync(It.Is<string>(instruction => instruction.Contains("Extract this CV into structured JSON", StringComparison.Ordinal)), It.IsAny<string>(), 3200, 900))
            .ReturnsAsync("""
            {
              "version":"1",
              "contact":{"fullName":"Connor Babbington"},
              "summary":["Built APIs and UIs"],
              "jobs":[],
              "education":[],
              "skills":[],
              "languages":[],
              "interests":[],
              "otherSections":[]
            }
            """);

        var controller = new ProfileCvController(userManager.Object, aiService.Object)
        {
            ControllerContext = new ControllerContext { HttpContext = new DefaultHttpContext() }
        };

        var file = new FormFile(new MemoryStream(Encoding.UTF8.GetBytes("# Connor Babbington\n\n## Professional Summary\nBuilt APIs and UIs")), 0, 62, "file", "resume.md")
        {
            Headers = new HeaderDictionary(),
            ContentType = "text/markdown"
        };
        var result = await controller.Upload(file);

        Assert.IsType<OkObjectResult>(result);
        Assert.Contains("Built APIs", user.ProfileCvText);
        Assert.Equal("Connor Babbington", StructuredCvProfileJson.Deserialize(user.ProfileCvStructureJson).Contact.FullName);
    }

    private static Mock<UserManager<ApplicationUser>> CreateUserManager()
    {
        var store = new Mock<IUserStore<ApplicationUser>>();
        return new Mock<UserManager<ApplicationUser>>(
            store.Object,
            Options.Create(new IdentityOptions()),
            new PasswordHasher<ApplicationUser>(),
            Array.Empty<IUserValidator<ApplicationUser>>(),
            Array.Empty<IPasswordValidator<ApplicationUser>>(),
            new UpperInvariantLookupNormalizer(),
            new IdentityErrorDescriber(),
            null!,
            new NullLogger<UserManager<ApplicationUser>>()
        );
    }
}