using Microsoft.EntityFrameworkCore;
using Serilog;
using TriliumMind.Data;
using TriliumMind.Data.Entities;

namespace TriliumMind.Services;

public class AppDbService
{
    private readonly Serilog.ILogger _log;
    private readonly IAppDbContext _db;
    public AppDbService(IAppDbContext dbContext)
    {
        _log = Log.ForContext<AppDbService>();
        _db = dbContext;
    }

    public async Task InitializeDatabaseAsync()
    {
        try
        {
            _log.Information("Checking database...");

            // Create db if not exists
            var created = await _db.Database.EnsureCreatedAsync();
            if (created)
            {
                _log.Information("Database created successfully");
            }
            else
            {
                _log.Information("Database already exists");
            }
        }
        catch (Exception ex)
        {
            _log.Error(ex, "Failed to initialize database");
            throw;
        }
    }

    #region Table: Configs
    public async Task<Dictionary<string, string>> LoadConfigAsync()
    {
        try
        {
            _log.Information("Loading configuration from database...");
            var configs = await _db.Configs.ToDictionaryAsync(c => c.Key, c => c.Value);
            _log.Information("Loaded {count} configuration entries", configs.Count);
            return configs;
        }
        catch (Exception ex)
        {
            _log.Error(ex, "Failed to load configuration from database");
            throw;
        }
    }
    public async Task<string?> GetConfigAsync(string key)
    {
        try
        {
            var config = await _db.Configs.FindAsync(key);
            return config?.Value;
        }
        catch (Exception ex)
        {
            _log.Error(ex, "Failed to get config value for key: {key}", key);
            throw;
        }
    }
    public async Task SetConfigAsync(string key, string value)
    {
        try
        {
            var config = await _db.Configs.FindAsync(key);
            if (config == null)
            {
                config = new Config { Key = key, Value = value };
                _db.Configs.Add(config);
            }
            else
            {
                config.Value = value;
                _db.Configs.Update(config);
            }
            await _db.SaveChangesAsync();
            _log.Debug("Config saved: {key} = {value}", key, value);
        }
        catch (Exception ex)
        {
            _log.Error(ex, "Failed to set config value for key: {key}", key);
            throw;
        }
    }
    #endregion Table: Configs


    public async Task UpsertJiraIssueAsync(JiraIssue issue, CancellationToken ct = default)
    {
        try
        {
            var existing = await _db.JiraIssues.FindAsync([issue.Key], ct);

            if (existing == null)
            {
                _db.JiraIssues.Add(issue);
                _log.Debug("Inserting new Jira issue: {key}", issue.Key);
            }
            else
            {
                if (issue.Updated > existing.Updated)
                {
                    existing.Summary = issue.Summary;
                    existing.Parent = issue.Parent;
                    existing.Type = issue.Type;
                    existing.Status = issue.Status;
                    existing.Assignee = issue.Assignee;
                    existing.Manager = issue.Manager;
                    existing.Due = issue.Due;
                    existing.Updated = issue.Updated;
                    existing.ObjectId = issue.ObjectId;
                    existing.NeedNotify = issue.NeedNotify;

                    _db.JiraIssues.Update(existing);
                    _log.Debug("Updating existing Jira issue: {key}", issue.Key);
                }
                else
                {
                    _log.Debug("Skipping Jira issue (not newer): {key}", issue.Key);
                }
            }

            await _db.SaveChangesAsync(ct);
        }
        catch (Exception ex)
        {
            _log.Error(ex, "Failed to upsert Jira issue: {key}", issue.Key);
            throw;
        }
    }

    public async Task UpsertJiraIssuesBatchAsync(IEnumerable<JiraIssue> issues, CancellationToken ct = default)
    {
        try
        {
            var issueList = issues.ToList();
            if (!issueList.Any())
                return;

            var keys = issueList.Select(i => i.Key).ToList();
            var existingIssues = await _db.JiraIssues
                .Where(ji => keys.Contains(ji.Key))
                .ToDictionaryAsync(ji => ji.Key, ct);

            int insertCount = 0, updateCount = 0, skipCount = 0;

            foreach (var issue in issueList)
            {
                if (!existingIssues.TryGetValue(issue.Key, out var existing))
                {
                    _db.JiraIssues.Add(issue);
                    insertCount++;
                }
                else if (issue.Updated > existing.Updated)
                {
                    existing.Summary = issue.Summary;
                    existing.Parent = issue.Parent;
                    existing.Type = issue.Type;
                    existing.Status = issue.Status;
                    existing.Assignee = issue.Assignee;
                    existing.Manager = issue.Manager;
                    existing.Due = issue.Due;
                    existing.Updated = issue.Updated;
                    existing.ObjectId = issue.ObjectId;
                    existing.NeedNotify = issue.NeedNotify;

                    _db.JiraIssues.Update(existing);
                    updateCount++;
                }
                else
                {
                    skipCount++;
                }
            }

            await _db.SaveChangesAsync(ct);
            _log.Information("Batch completed: {insert} inserted, {update} updated, {skip} skipped out of {total} issues",
                insertCount, updateCount, skipCount, issueList.Count);
        }
        catch (Exception ex)
        {
            _log.Error(ex, "Failed to batch upsert Jira issues");
            throw;
        }
    }
}