using Microsoft.EntityFrameworkCore;
using mws.backend.dotnet.application.Auth;
using mws.backend.dotnet.application.Permissions;
using mws.backend.dotnet.domain.Documents;
using mws.backend.dotnet.domain.MasterData;
using mws.backend.dotnet.domain.Projects;
using mws.backend.dotnet.domain.Roles;
using mws.backend.dotnet.domain.Tasks;
using mws.backend.dotnet.domain.Users;
using TaskPriority = mws.backend.dotnet.domain.Tasks.TaskPriority;
using TaskStatus = mws.backend.dotnet.domain.Tasks.TaskStatus;

namespace mws.backend.dotnet.infrastructure.Persistence;

public static class DbSeeder
{
    public static async Task SeedAsync(AppDbContext db, IPasswordHasher passwordHasher)
    {
        await SeedMasterDataAsync(db);
        await EnsureRolesAsync(db);

        var admin = await EnsureUserAsync(db, passwordHasher, "admin", "Admin", "Admin");
        var namdh = await EnsureUserAsync(db, passwordHasher, "namdh", "Nam DH", "Member");

        if (await db.Projects.AnyAsync())
        {
            return;
        }

        var now = DateTime.UtcNow;

        var project = new Project
        {
            Id = Guid.NewGuid(),
            Name = "MWS",
            Description = "My Workspace - internal tool for the team.",
            Status = ProjectStatus.Active,
            CreatedBy = admin.Id,
            CreatedAt = now,
            UpdatedBy = admin.Id,
            UpdatedAt = now,
        };

        db.Projects.Add(project);

        db.ProjectMembers.AddRange(
            new ProjectMember { ProjectId = project.Id, UserId = admin.Id, Role = MemberRole.Owner },
            new ProjectMember { ProjectId = project.Id, UserId = namdh.Id, Role = MemberRole.Member });

        db.ProjectMemberPermissions.AddRange(
            new ProjectMemberPermission { ProjectId = project.Id, UserId = namdh.Id, Screen = ProjectPermissionScreens.Documents, CanView = true });

        await db.SaveChangesAsync();

        var requirements = new Document
        {
            Id = Guid.NewGuid(), ProjectId = project.Id, ParentId = null,
            Title = "Requirements", Type = DocumentType.Folder,
            CreatedBy = admin.Id, CreatedAt = now, UpdatedBy = admin.Id, UpdatedAt = now,
        };

        var design = new Document
        {
            Id = Guid.NewGuid(), ProjectId = project.Id, ParentId = null,
            Title = "Technical Design", Type = DocumentType.Folder,
            CreatedBy = admin.Id, CreatedAt = now, UpdatedBy = admin.Id, UpdatedAt = now,
        };

        var notes = new Document
        {
            Id = Guid.NewGuid(), ProjectId = project.Id, ParentId = null,
            Title = "Notes", Type = DocumentType.Folder,
            CreatedBy = admin.Id, CreatedAt = now, UpdatedBy = admin.Id, UpdatedAt = now,
        };

        db.Documents.AddRange(requirements, design, notes);
        db.Documents.Add(new Document
        {
            Id = Guid.NewGuid(), ProjectId = project.Id, ParentId = requirements.Id,
            Title = "Authentication", Type = DocumentType.Document,
            CreatedBy = admin.Id, CreatedAt = now, UpdatedBy = admin.Id, UpdatedAt = now,
        });
        db.Documents.Add(new Document
        {
            Id = Guid.NewGuid(), ProjectId = project.Id, ParentId = requirements.Id,
            Title = "User Management", Type = DocumentType.Document,
            CreatedBy = admin.Id, CreatedAt = now, UpdatedBy = admin.Id, UpdatedAt = now,
        });
        db.Documents.Add(new Document
        {
            Id = Guid.NewGuid(), ProjectId = project.Id, ParentId = design.Id,
            Title = "API Design", Type = DocumentType.Document,
            CreatedBy = admin.Id, CreatedAt = now, UpdatedBy = admin.Id, UpdatedAt = now,
        });
        await db.SaveChangesAsync();

        db.Tasks.AddRange(
            new TaskItem
            {
                Id = Guid.NewGuid(), ProjectId = project.Id, Title = "Set up solution",
                Status = TaskStatus.Done, Priority = TaskPriority.High, AssigneeId = admin.Id,
                CreatedBy = admin.Id, CreatedAt = now, UpdatedAt = now,
            },
            new TaskItem
            {
                Id = Guid.NewGuid(), ProjectId = project.Id, Title = "Implement authentication",
                Description = "Login endpoint with BCrypt and JWT.",
                Status = TaskStatus.InProgress, Priority = TaskPriority.High, AssigneeId = namdh.Id,
                DueDate = now.AddDays(3),
                CreatedBy = admin.Id, CreatedAt = now, UpdatedAt = now,
            },
            new TaskItem
            {
                Id = Guid.NewGuid(), ProjectId = project.Id, Title = "Task board drag & drop",
                Status = TaskStatus.Todo, Priority = TaskPriority.Medium, AssigneeId = namdh.Id,
                DueDate = now.AddDays(7),
                CreatedBy = admin.Id, CreatedAt = now, UpdatedAt = now,
            },
            new TaskItem
            {
                Id = Guid.NewGuid(), ProjectId = project.Id, Title = "Polish documents UI",
                Status = TaskStatus.Todo, Priority = TaskPriority.Low,
                CreatedBy = admin.Id, CreatedAt = now, UpdatedAt = now,
            });

        await db.SaveChangesAsync();
    }

    private static async Task EnsureRolesAsync(AppDbContext db)
    {
        var now = DateTime.UtcNow;

        await SyncSystemRoleAsync(
            db,
            "Admin",
            _ => (View: true, Create: true, Edit: true, Delete: true),
            now);

        await SyncSystemRoleAsync(
            db,
            "Member",
            screen => screen.Key switch
            {
                "users" or "permissions" or "masterdata" => (View: false, Create: false, Edit: false, Delete: false),
                "projects" => (View: true, Create: false, Edit: false, Delete: false),
                _ => (View: true, Create: true, Edit: true, Delete: false),
            },
            now);
    }

    private static async Task SyncSystemRoleAsync(
        AppDbContext db,
        string name,
        Func<ScreenDefinition, (bool View, bool Create, bool Edit, bool Delete)> rule,
        DateTime now)
    {
        var role = await db.Roles
            .Include(r => r.Permissions)
            .FirstOrDefaultAsync(r => r.Name == name);

        if (role is null)
        {
            role = new Role { Id = Guid.NewGuid(), Name = name, IsSystem = true, CreatedAt = now, UpdatedAt = now };
            db.Roles.Add(role);
        }

        var byScreen = role.Permissions.ToDictionary(p => p.Screen);
        foreach (var screen in ScreenCatalog.Screens)
        {
            if (!byScreen.TryGetValue(screen.Key, out var permission))
            {
                permission = new RolePermission { RoleId = role.Id, Screen = screen.Key };
                role.Permissions.Add(permission);
            }

            var (view, create, edit, delete) = rule(screen);
            permission.CanView = view;
            permission.CanCreate = create;
            permission.CanEdit = edit;
            permission.CanDelete = delete;
        }

        role.UpdatedAt = now;
        await db.SaveChangesAsync();
    }

    private static async Task<User> EnsureUserAsync(AppDbContext db, IPasswordHasher passwordHasher, string username, string displayName, string roleName)
    {
        var existing = await db.Users.Include(u => u.UserRoles).FirstOrDefaultAsync(u => u.Username == username);
        if (existing != null)
        {
            return existing;
        }

        var role = await db.Roles.FirstAsync(r => r.Name == roleName);
        var now = DateTime.UtcNow;
        var user = new User
        {
            Id = Guid.NewGuid(),
            Username = username,
            PasswordHash = passwordHasher.Hash("password"),
            DisplayName = displayName,
            UserRoles = new List<UserRole> { new UserRole { RoleId = role.Id } },
            CreatedAt = now,
            UpdatedAt = now,
        };

        db.Users.Add(user);
        await db.SaveChangesAsync();
        return user;
    }

    private static async Task SeedMasterDataAsync(AppDbContext db)
    {
        if (await db.MasterData.AnyAsync())
        {
            return;
        }

        var now = DateTime.UtcNow;

        MasterDataEntry Entry(string group, string label, string value, int sortOrder) => new()
        {
            Id = Guid.NewGuid(), Group = group, Label = label, Value = value, SortOrder = sortOrder,
            IsActive = true, CreatedAt = now, UpdatedAt = now,
        };

        db.MasterData.AddRange(
            Entry("task_status", "Todo", nameof(TaskStatus.Todo), 1),
            Entry("task_status", "In Progress", nameof(TaskStatus.InProgress), 2),
            Entry("task_status", "Done", nameof(TaskStatus.Done), 3),
            Entry("task_status", "Cancelled", nameof(TaskStatus.Cancelled), 4),
            Entry("task_priority", "Low", nameof(TaskPriority.Low), 1),
            Entry("task_priority", "Medium", nameof(TaskPriority.Medium), 2),
            Entry("task_priority", "High", nameof(TaskPriority.High), 3),
            Entry("project_status", "Active", nameof(ProjectStatus.Active), 1),
            Entry("project_status", "Archived", nameof(ProjectStatus.Archived), 2),
            Entry("member_role", "Owner", nameof(MemberRole.Owner), 1),
            Entry("member_role", "Member", nameof(MemberRole.Member), 2),
            Entry("document_type", "Folder", nameof(DocumentType.Folder), 1),
            Entry("document_type", "Document", nameof(DocumentType.Document), 2));

        await db.SaveChangesAsync();
    }
}