using Microsoft.SharePoint.Client;
using PnP.Framework.Sites;
using Serilog;
using SharepointToolbox.Web.Core.Helpers;
using SharepointToolbox.Web.Core.Models;
using SharepointToolbox.Web.Services.Audit;

namespace SharepointToolbox.Web.Services;

public class BulkSiteService : IBulkSiteService
{
    private readonly IAuditService _audit;

    public BulkSiteService(IAuditService audit) { _audit = audit; }

    public async Task<BulkOperationSummary<BulkSiteRow>> CreateSitesAsync(
        ClientContext adminCtx, IReadOnlyList<BulkSiteRow> rows,
        IProgress<OperationProgress> progress, CancellationToken ct)
    {
        var createdUrls = new System.Collections.Concurrent.ConcurrentBag<string>();
        var result = await BulkOperationRunner.RunAsync(rows,
            async (row, idx, token) =>
            {
                var siteUrl = await CreateSingleSiteAsync(adminCtx, row, progress, token);
                createdUrls.Add(siteUrl);
                Log.Information("Created site: {Name} ({Type}) at {Url}", row.Name, row.Type, siteUrl);
            },
            progress, ct);
        var tenantHost = Uri.TryCreate(adminCtx.Url, UriKind.Absolute, out var u) ? u.Host : adminCtx.Url;
        await _audit.LogAsync("BulkCreateSites", tenantHost, createdUrls, $"{result.SuccessCount} created, {(result.TotalCount - result.SuccessCount)} failed");
        return result;
    }

    private static async Task<string> CreateSingleSiteAsync(ClientContext adminCtx, BulkSiteRow row, IProgress<OperationProgress> progress, CancellationToken ct) =>
        row.Type.Equals("Team", StringComparison.OrdinalIgnoreCase) ? await CreateTeamSiteAsync(adminCtx, row, progress, ct)
        : row.Type.Equals("Communication", StringComparison.OrdinalIgnoreCase) ? await CreateCommunicationSiteAsync(adminCtx, row, progress, ct)
        : throw new InvalidOperationException($"Unknown site type: {row.Type}");

    private static async Task<string> CreateTeamSiteAsync(ClientContext adminCtx, BulkSiteRow row, IProgress<OperationProgress> progress, CancellationToken ct)
    {
        var owners = ParseEmails(row.Owners);
        if (owners.Count == 0) throw new InvalidOperationException($"Team site '{row.Name}' requires at least one owner.");
        var creationInfo = new TeamSiteCollectionCreationInformation { DisplayName = row.Name, Alias = row.Alias, Description = string.Empty, IsPublic = false, Owners = owners.ToArray() };
        progress.Report(new OperationProgress(0, 0, $"Creating Team site: {row.Name}..."));
        using var siteCtx = await adminCtx.CreateSiteAsync(creationInfo);
        siteCtx.Load(siteCtx.Web, w => w.Url);
        await ExecuteQueryRetryHelper.ExecuteQueryRetryAsync(siteCtx, progress, ct);
        var siteUrl = siteCtx.Web.Url;
        foreach (var memberEmail in ParseEmails(row.Members))
        {
            ct.ThrowIfCancellationRequested();
            try { var user = siteCtx.Web.EnsureUser(memberEmail); siteCtx.Load(user); await ExecuteQueryRetryHelper.ExecuteQueryRetryAsync(siteCtx, progress, ct); siteCtx.Web.AssociatedMemberGroup.Users.AddUser(user); await ExecuteQueryRetryHelper.ExecuteQueryRetryAsync(siteCtx, progress, ct); }
            catch (OperationCanceledException) { throw; }
            catch (Exception ex) { Log.Warning("Failed to add member {Email} to {Site}: {Error}", memberEmail, row.Name, ex.Message); }
        }
        return siteUrl;
    }

    private static async Task<string> CreateCommunicationSiteAsync(ClientContext adminCtx, BulkSiteRow row, IProgress<OperationProgress> progress, CancellationToken ct)
    {
        var alias = !string.IsNullOrWhiteSpace(row.Alias) ? row.Alias : SanitizeAlias(row.Name);
        var tenantUrl = new Uri(adminCtx.Url);
        var creationInfo = new CommunicationSiteCollectionCreationInformation { Title = row.Name, Url = $"https://{tenantUrl.Host}/sites/{alias}", Description = string.Empty };
        progress.Report(new OperationProgress(0, 0, $"Creating Communication site: {row.Name}..."));
        using var siteCtx = await adminCtx.CreateSiteAsync(creationInfo);
        siteCtx.Load(siteCtx.Web, w => w.Url);
        await ExecuteQueryRetryHelper.ExecuteQueryRetryAsync(siteCtx, progress, ct);
        var createdUrl = siteCtx.Web.Url;
        foreach (var ownerEmail in ParseEmails(row.Owners))
        {
            ct.ThrowIfCancellationRequested();
            try { var user = siteCtx.Web.EnsureUser(ownerEmail); siteCtx.Load(user); await ExecuteQueryRetryHelper.ExecuteQueryRetryAsync(siteCtx, progress, ct); siteCtx.Web.AssociatedOwnerGroup.Users.AddUser(user); await ExecuteQueryRetryHelper.ExecuteQueryRetryAsync(siteCtx, progress, ct); }
            catch (OperationCanceledException) { throw; }
            catch (Exception ex) { Log.Warning("Failed to add owner {Email}: {Error}", ownerEmail, ex.Message); }
        }
        return createdUrl;
    }

    private static List<string> ParseEmails(string commaSeparated) =>
        string.IsNullOrWhiteSpace(commaSeparated) ? new List<string>() :
        commaSeparated.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries).Where(e => !string.IsNullOrWhiteSpace(e)).ToList();

    private static string SanitizeAlias(string name) =>
        new string(name.Where(c => char.IsLetterOrDigit(c) || c == ' ' || c == '-').ToArray()).Replace(' ', '-').ToLowerInvariant();
}