@page "/calendar/event-occurrences/import"
@attribute [Authorize]
@using Core.Models
@using Core.Services
@using Microsoft.EntityFrameworkCore
@inject IEventOccurrenceParserService ParserService
@inject AppDbContext Context
@inject NavigationManager NavigationManager
@inject ISnackbar Snackbar
@inject IDialogService DialogService

<PageHeader 
    Title="Import Event Occurrences" 
    Description="Parse and import event occurrence data from text"
    ShowBackButton="true"
    BackButtonUrl="/calendar/event-occurrences" />

<MudGrid>
    <MudItem xs="12" md="6">
        <MudPaper Elevation="2" Class="pa-3 pa-md-6">
            <MudText Typo="Typo.h5" Class="mb-4">Paste Event Occurrence Data</MudText>
            <MudStack Spacing="3">

                <MudStack Row="true" Spacing="2">
                    <MudButton 
                        Variant="Variant.Filled" 
                        Color="Color.Primary"
                        StartIcon="@Icons.Material.Filled.Article"
                        OnClick="HandleParse"
                        Disabled="@_isParsing">
                        Parse
                    </MudButton>
                    <MudButton 
                        Variant="Variant.Text" 
                        OnClick="HandleClear"
                        Disabled="@_isParsing">
                        Clear
                    </MudButton>
                </MudStack>
                <MudTextField 
                    T="string" 
                    Label="Event Occurrence Text" 
                    @bind-Value="_inputText"
                    
                    Variant="Variant.Outlined"
                    Lines="15"
                    AutoGrow="true"
                    Placeholder="Paste event occurrence text here..."
                    HelperText="Paste the event schedule text in the format expected by the parser" />
                <!-- @bind-Value:event="oninput" -->
            </MudStack>
        </MudPaper>
    </MudItem>

    <MudItem xs="12" md="6">
        <MudPaper Elevation="2" Class="pa-3 pa-md-6">
            <MudText Typo="Typo.h5" Class="mb-4">Parsed Results</MudText>
            
            @if (_isParsing)
            {
                <MudProgressLinear Indeterminate="true" Class="mb-4" />
                <MudText>Parsing...</MudText>
            }
            else if (_parseResult == null)
            {
                <MudText Class="mud-text-secondary">Parse text to see results here</MudText>
            }
            else
            {
                <MudStack Spacing="3">
                    @* Errors *@
                    @if (_parseResult.Errors.Any())
                    {
                        @foreach (var error in _parseResult.Errors)
                        {
                            <MudAlert Severity="Severity.Error" Dense="true">@error</MudAlert>
                        }
                    }

                    @* Warnings *@
                    @if (_parseResult.Warnings.Any())
                    {
                        @foreach (var warning in _parseResult.Warnings)
                        {
                            <MudAlert Severity="Severity.Warning" Dense="true">@warning</MudAlert>
                        }
                    }

                    @* Detailed Parsing Issues *@
                    @if (_parseResult.Issues.Any())
                    {
                        <MudExpansionPanels Elevation="0" Class="mt-2">
                            <MudExpansionPanel Text="@($"Parsing Issues ({_parseResult.Issues.Count} found on {_parseResult.Issues.Select(i => i.LineNumber).Distinct().Count()} line(s))")"
                                             Icon="@Icons.Material.Filled.Warning"
                                             iconcolor="Color.Warning">
                                <MudTable Items="@_parseResult.Issues" Dense="true" Hover="true" Striped="true" sortmode="SortMode.Multiple">
                                    <HeaderContent>
                                        <MudTh>Line</MudTh>
                                        <MudTh>Type</MudTh>
                                        <MudTh>Content</MudTh>
                                        <MudTh>Message</MudTh>
                                    </HeaderContent>
                                    <RowTemplate>
                                        <MudTd DataLabel="Line">@context.LineNumber</MudTd>
                                        <MudTd DataLabel="Type">
                                            <MudChip T="string" Size="Size.Small" Color="@GetIssueTypeColor(context.IssueType)">
                                                @context.IssueType
                                            </MudChip>
                                        </MudTd>
                                        <MudTd DataLabel="Content">
                                            <code style="font-size: 0.85em; max-width: 200px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; display: block;" title="@context.LineContent">@context.LineContent</code>
                                        </MudTd>
                                        <MudTd DataLabel="Message">@context.Message</MudTd>
                                    </RowTemplate>
                                </MudTable>
                            </MudExpansionPanel>
                        </MudExpansionPanels>
                    }

                    @* Summary *@
                    @if (_parseResult.IsSuccess && _parseResult.TotalParsed > 0)
                    {
                        <MudAlert Severity="Severity.Success" Dense="true">
                            Successfully parsed @_parseResult.TotalParsed occurrence(s) from @_parseResult.Occurrences.Count event definition(s)
                            @if (_parseResult.SkippedEventCount > 0)
                            {
                                <text> (Skipped @_parseResult.SkippedEventCount event occurrence(s) from other school level)</text>
                            }
                        </MudAlert>
                    }

                    @* Skipped Section Headers *@
                    @if (_parseResult.SkippedSectionHeaders.Any() && _parseResult.IsSuccess)
                    {
                        <MudExpansionPanels Elevation="0" Class="mt-2">
                            <MudExpansionPanel Text="@($"Skipped Section Headers ({_parseResult.SkippedSectionHeaders.Count})")"
                                             Icon="@Icons.Material.Filled.Info"
                                             iconcolor="Color.Info">
                                <MudList T="string">
                                    @foreach (var header in _parseResult.SkippedSectionHeaders)
                                    {
                                        <MudListItem T="string">
                                            <MudText>@header</MudText>
                                        </MudListItem>
                                    }
                                </MudList>
                            </MudExpansionPanel>
                        </MudExpansionPanels>
                    }

                    @* Locations Summary *@
                    @if (_parseResult.IsSuccess && _parseResult.Occurrences.Any())
                    {
                        var allLocations = _parseResult.Occurrences.Values
                            .SelectMany(list => list)
                            .Select(eo => eo.Location)
                            .Where(loc => !string.IsNullOrWhiteSpace(loc))
                            .Cast<string>() // Cast to non-nullable string after null check
                            .Distinct()
                            .OrderBy(loc => loc)
                            .ToList();
                        
                        // Check which locations have warnings (long or contain date/time)
                        var dateTimePattern = new System.Text.RegularExpressions.Regex(
                            @"\b(January|February|March|April|May|June|July|August|September|October|November|December)\s+\d{1,2}\b|\b\d{1,2}:\d{2}\s*(a|p)\.?m\.?\b|\bNOON\b",
                            System.Text.RegularExpressions.RegexOptions.IgnoreCase);
                        
                        var longLocations = allLocations.Where(loc => loc.Length > 50).ToList();
                        var locationsWithDateTime = allLocations.Where(loc => dateTimePattern.IsMatch(loc)).ToList();
                        
                        @if (allLocations.Any())
                        {
                            var warningCount = longLocations.Count + locationsWithDateTime.Count;
                            <MudText Typo="Typo.h6" Class="mt-4 mb-2">Parsed Locations (@allLocations.Count unique@(warningCount > 0 ? $", {warningCount} with warnings" : ""))</MudText>
                            <MudExpansionPanels Elevation="0">
                                <MudExpansionPanel Text="All Locations">
                                    <MudList T="string">
                                        @foreach (var location in allLocations)
                                        {
                                            var isLong = longLocations.Contains(location);
                                            var hasDateTime = locationsWithDateTime.Contains(location);
                                            var hasWarning = isLong || hasDateTime;
                                            <MudListItem T="string">
                                                <MudStack Row="true" Spacing="2" AlignItems="AlignItems.Center">
                                                    @if (hasWarning)
                                                    {
                                                        <MudChip T="string" Color="Color.Warning" Size="Size.Small">Warning</MudChip>
                                                    }
                                                    <MudText Style="@(hasWarning ? "color: var(--mud-palette-warning);" : "")">@location</MudText>
                                                </MudStack>
                                            </MudListItem>
                                        }
                                    </MudList>
                                </MudExpansionPanel>
                            </MudExpansionPanels>
                        }
                    }

                    @* Parsed Occurrences List *@
                    @if (_parseResult.IsSuccess && _parseResult.Occurrences.Any())
                    {
                        <MudText Typo="Typo.h6" Class="mt-4 mb-2">Occurrences by Event:</MudText>
                        <MudExpansionPanels Elevation="0">
                            @foreach (var kvp in _parseResult.Occurrences.OrderBy(x => GetEventName(x.Key)))
                            {
                                <MudExpansionPanel Text="@GetEventName(kvp.Key)">
                                    <MudTable Items="@kvp.Value" Dense="true" Hover="true" Striped="true">
                                        <HeaderContent>
                                            <MudTh>Name</MudTh>
                                            <MudTh>Date</MudTh>
                                            <MudTh>Time</MudTh>
                                            <MudTh>Location</MudTh>
                                        </HeaderContent>
                                        <RowTemplate>
                                            <MudTd DataLabel="Name">@context.Name</MudTd>
                                            <MudTd DataLabel="Date">@context.Date</MudTd>
                                            <MudTd DataLabel="Time">@context.Time</MudTd>
                                            <MudTd DataLabel="Location">@(context.Location ?? "-")</MudTd>
                                        </RowTemplate>
                                    </MudTable>
                                </MudExpansionPanel>
                            }
                        </MudExpansionPanels>

                        <MudStack Row="true" Spacing="2" Class="mt-4">
                            <MudButton 
                                Variant="Variant.Filled" 
                                Color="Color.Success"
                                StartIcon="@Icons.Material.Filled.Save"
                                OnClick="HandleSaveToDatabase"
                                Disabled="@_isSaving">
                                Save to Database
                            </MudButton>
                            <MudButton 
                                Variant="Variant.Text" 
                                OnClick="HandleClearResults">
                                Clear Results
                            </MudButton>
                        </MudStack>
                    }
                    else if (_parseResult.IsSuccess && _parseResult.TotalParsed == 0)
                    {
                        <MudAlert Severity="Severity.Info" Dense="true">
                            No occurrences were parsed from the text. Please check the format.
                        </MudAlert>
                    }
                </MudStack>
            }
        </MudPaper>
    </MudItem>
</MudGrid>

@code {
    private string _inputText = string.Empty;
    private EventOccurrenceParseResult? _parseResult;
    private bool _isParsing = false;
    private bool _isSaving = false;

    private async Task HandleParse()
    {
        if (string.IsNullOrWhiteSpace(_inputText))
        {
            Snackbar.Add("Please enter text to parse", Severity.Warning);
            return;
        }

        _isParsing = true;
        try
        {
            // Get EventDefinitions from database
            var events = await Context.Events.ToListAsync();
            
            // Parse the text
            _parseResult = ParserService.ParseFromText(_inputText, events);
        }
        catch (Exception ex)
        {
            Snackbar.Add($"Error parsing text: {ex.Message}", Severity.Error);
            _parseResult = new EventOccurrenceParseResult
            {
                Errors = { $"Error: {ex.Message}" }
            };
        }
        finally
        {
            _isParsing = false;
        }
    }

    private void HandleClear()
    {
        _inputText = string.Empty;
        _parseResult = null;
    }

    private void HandleClearResults()
    {
        _parseResult = null;
    }

    private async Task HandleSaveToDatabase()
    {
        if (_parseResult == null || !_parseResult.IsSuccess || _parseResult.TotalParsed == 0)
        {
            Snackbar.Add("No valid parsed occurrences to save", Severity.Warning);
            return;
        }

        _isSaving = true;
        try
        {
            var savedCount = 0;
            var skippedCount = 0;
            
            foreach (var kvp in _parseResult.Occurrences)
            {
                foreach (var occurrence in kvp.Value)
                {
                    // Check for duplicates before adding
                    var isDuplicate = await IsDuplicate(occurrence);
                    if (isDuplicate)
                    {
                        skippedCount++;
                        continue;
                    }
                    
                    // Add each occurrence to the database
                    await Context.EventOccurrences.AddAsync(occurrence);
                    savedCount++;
                }
            }

            await Context.SaveChangesAsync();
            
            var message = $"Successfully saved {savedCount} occurrence(s) to database";
            if (skippedCount > 0)
            {
                message += $" ({skippedCount} duplicate(s) skipped)";
            }
            Snackbar.Add(message, Severity.Success);
            
            // Clear input and output instead of navigating
            _inputText = string.Empty;
            _parseResult = null;
        }
        catch (Exception ex)
        {
            Snackbar.Add($"Error saving to database: {ex.Message}", Severity.Error);
        }
        finally
        {
            _isSaving = false;
        }
    }

    private async Task<bool> IsDuplicate(EventOccurrence occurrence)
    {
        // Check if an occurrence with the same name, date, time, location, and event definition already exists
        var query = Context.EventOccurrences
            .Where(eo => eo.Name == occurrence.Name &&
                        eo.StartTime.Date == occurrence.StartTime.Date &&
                        eo.Time == occurrence.Time &&
                        eo.Location == occurrence.Location);

        // Match by EventDefinitionId if it exists, otherwise match by SpecialEventType
        if (occurrence.EventDefinitionId.HasValue)
        {
            query = query.Where(eo => eo.EventDefinitionId == occurrence.EventDefinitionId);
        }
        else if (!string.IsNullOrEmpty(occurrence.SpecialEventType))
        {
            query = query.Where(eo => eo.SpecialEventType == occurrence.SpecialEventType);
        }
        else
        {
            // If neither EventDefinitionId nor SpecialEventType is set, match by both being null/empty
            query = query.Where(eo => eo.EventDefinitionId == null && string.IsNullOrEmpty(eo.SpecialEventType));
        }

        return await query.AnyAsync();
    }

    private string GetEventName(EventDefinition eventDefinition)
    {
        if (eventDefinition == EventDefinition.GeneralSchedule)
            return "General Schedule";
        if (eventDefinition == EventDefinition.MeetTheCandidates)
            return "Meet the Candidates";
        if (eventDefinition == EventDefinition.ChapterOfficerMeeting)
            return "Chapter Officer Meeting";
        if (eventDefinition == EventDefinition.VotingDelegateMeeting)
            return "Voting Delegate Meeting";
        if (eventDefinition == EventDefinition.SocialGathering)
            return "Social Gathering";
        return eventDefinition.Name;
    }

    private Color GetIssueTypeColor(ParsingIssueType issueType)
    {
        return issueType switch
        {
            ParsingIssueType.UnmatchedLine => Color.Info,
            ParsingIssueType.MissingEventDefinition => Color.Warning,
            ParsingIssueType.TimeParseFailure => Color.Error,
            ParsingIssueType.DateParseFailure => Color.Error,
            ParsingIssueType.InvalidFormat => Color.Error,
            _ => Color.Default
        };
    }

}