using System.Net.Http.Json;
using DashCaddy.Desktop.Models;

namespace DashCaddy.Desktop.Services;

public enum DnsProviderType
{
    None,           // No DNS management - use existing DNS
    Technitium,
    CoreDNS,
    Cloudflare,
    Route53,
    Custom
}

public class DnsProviderConfig
{
    public DnsProviderType Type { get; set; }
    public string Name { get; set; }
    public string BaseUrl { get; set; }
    public string ApiKey { get; set; }
    public string ZoneId { get; set; }
    public Dictionary<string, string> Extra { get; set; } = new();
}

public class DnsClient
{
    private readonly HttpClient _httpClient;
    private readonly DnsProviderConfig _config;

    public DnsProviderType ProviderType => _config?.Type ?? DnsProviderType.None;

    public DnsClient(DnsProviderConfig config)
    {
        _config = config;
        if (config?.Type != DnsProviderType.None)
        {
            _httpClient = new HttpClient { BaseAddress = new Uri(config.BaseUrl) };
            if (!string.IsNullOrEmpty(config.ApiKey))
            {
                _httpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer {config.ApiKey}");
            }
        }
    }

    public static DnsClient Create(DnsProviderType type, Dictionary<string, string> settings)
    {
        if (type == DnsProviderType.None)
        {
            return null;
        }
        
        var config = type switch
        {
            DnsProviderType.Technitium => new DnsProviderConfig
            {
                Type = DnsProviderType.Technitium,
                Name = "Technitium DNS",
                BaseUrl = settings.GetValueOrDefault("technitium_url", "http://localhost:5380/api"),
                ApiKey = settings.GetValueOrDefault("technitium_api_key", ""),
                ZoneId = settings.GetValueOrDefault("technitium_zone", "")
            },
            DnsProviderType.CoreDNS => new DnsProviderConfig
            {
                Type = DnsProviderType.CoreDNS,
                Name = "CoreDNS",
                BaseUrl = settings.GetValueOrDefault("coredns_api_url", "http://localhost:8080"),
                ApiKey = "",
                ZoneId = settings.GetValueOrDefault("coredns_zone", "local")
            },
            DnsProviderType.Cloudflare => new DnsProviderConfig
            {
                Type = DnsProviderType.Cloudflare,
                Name = "Cloudflare",
                BaseUrl = "https://api.cloudflare.com/client/v4",
                ApiKey = settings.GetValueOrDefault("cloudflare_api_token", ""),
                ZoneId = settings.GetValueOrDefault("cloudflare_zone_id", "")
            },
            DnsProviderType.Route53 => new DnsProviderConfig
            {
                Type = DnsProviderType.Route53,
                Name = "AWS Route 53",
                BaseUrl = "https://route53.amazonaws.com",
                ApiKey = settings.GetValueOrDefault("aws_access_key", ""),
                Extra = new Dictionary<string, string>
                {
                    ["secret_key"] = settings.GetValueOrDefault("aws_secret_key", ""),
                    ["region"] = settings.GetValueOrDefault("aws_region", "us-east-1")
                }
            },
            _ => new DnsProviderConfig
            {
                Type = DnsProviderType.Custom,
                Name = "Custom DNS",
                BaseUrl = settings.GetValueOrDefault("custom_dns_url", ""),
                ApiKey = settings.GetValueOrDefault("custom_dns_key", "")
            }
        };

        return new DnsClient(config);
    }

    public async Task<List<DnsRecord>> GetRecordsAsync(string zone = null)
    {
        if (_config?.Type == DnsProviderType.None) return new List<DnsRecord>();
        
        zone ??= _config?.ZoneId;
        if (string.IsNullOrEmpty(zone)) return new List<DnsRecord>();
        
        return _config.Type switch
        {
            DnsProviderType.Technitium => await GetTechnitiumRecordsAsync(zone),
            DnsProviderType.CoreDNS => await GetCoreDnsRecordsAsync(zone),
            DnsProviderType.Cloudflare => await GetCloudflareRecordsAsync(zone),
            DnsProviderType.Route53 => await GetRoute53RecordsAsync(zone),
            _ => new List<DnsRecord>()
        };
    }

    public async Task<DnsRecord> CreateRecordAsync(string zone, DnsRecord record)
    {
        if (_config?.Type == DnsProviderType.None) return record;
        
        return _config.Type switch
        {
            DnsProviderType.Technitium => await CreateTechnitiumRecordAsync(zone, record),
            DnsProviderType.CoreDNS => await CreateCoreDnsRecordAsync(zone, record),
            DnsProviderType.Cloudflare => await CreateCloudflareRecordAsync(zone, record),
            DnsProviderType.Route53 => await CreateRoute53RecordAsync(zone, record),
            _ => record
        };
    }

    public async Task<DnsRecord> UpdateRecordAsync(string zone, string recordId, DnsRecord record)
    {
        if (_config?.Type == DnsProviderType.None) return record;
        
        return _config.Type switch
        {
            DnsProviderType.Technitium => await UpdateTechnitiumRecordAsync(zone, recordId, record),
            DnsProviderType.CoreDNS => await UpdateCoreDnsRecordAsync(zone, recordId, record),
            DnsProviderType.Cloudflare => await UpdateCloudflareRecordAsync(zone, recordId, record),
            DnsProviderType.Route53 => await UpdateRoute53RecordAsync(zone, recordId, record),
            _ => record
        };
    }

    public async Task DeleteRecordAsync(string zone, string recordId)
    {
        if (_config?.Type == DnsProviderType.None) return;
        
        switch (_config.Type)
        {
            case DnsProviderType.Technitium:
                await DeleteTechnitiumRecordAsync(zone, recordId);
                break;
            case DnsProviderType.CoreDNS:
                await DeleteCoreDnsRecordAsync(zone, recordId);
                break;
            case DnsProviderType.Cloudflare:
                await DeleteCloudflareRecordAsync(zone, recordId);
                break;
            case DnsProviderType.Route53:
                await DeleteRoute53RecordAsync(zone, recordId);
                break;
        }
    }

    // ─── Technitium ───
    private async Task<List<DnsRecord>> GetTechnitiumRecordsAsync(string zone)
    {
        var response = await _httpClient.GetAsync($"/zones/{zone}/records");
        response.EnsureSuccessStatusCode();
        var result = await response.Content.ReadFromJsonAsync<TechnitiumZoneResponse>();
        return result?.Records?.Select(r => new DnsRecord
        {
            Id = r.Id,
            Name = r.Name,
            Type = r.Type,
            Content = r.Value,
            Ttl = r.Ttl
        }).ToList() ?? new List<DnsRecord>();
    }

    private async Task<DnsRecord> CreateTechnitiumRecordAsync(string zone, DnsRecord record)
    {
        var req = new TechnitiumRecordRequest
        {
            Name = record.Name,
            Type = record.Type,
            Value = record.Content,
            Ttl = record.Ttl
        };
        var response = await _httpClient.PostAsJsonAsync($"/zones/{zone}/records", req);
        response.EnsureSuccessStatusCode();
        var result = await response.Content.ReadFromJsonAsync<TechnitiumRecordResponse>();
        record.Id = result?.Record?.Id;
        return record;
    }

    private async Task<DnsRecord> UpdateTechnitiumRecordAsync(string zone, string recordId, DnsRecord record)
    {
        var req = new TechnitiumRecordRequest
        {
            Name = record.Name,
            Type = record.Type,
            Value = record.Content,
            Ttl = record.Ttl
        };
        var response = await _httpClient.PutAsJsonAsync($"/zones/{zone}/records/{recordId}", req);
        response.EnsureSuccessStatusCode();
        return record;
    }

    private async Task DeleteTechnitiumRecordAsync(string zone, string recordId)
    {
        var response = await _httpClient.DeleteAsync($"/zones/{zone}/records/{recordId}");
        response.EnsureSuccessStatusCode();
    }

    // ─── CoreDNS (via API wrapper) ───
    private async Task<List<DnsRecord>> GetCoreDnsRecordsAsync(string zone)
    {
        var response = await _httpClient.GetAsync($"/api/v1/dns/zones/{zone}/records");
        response.EnsureSuccessStatusCode();
        var result = await response.Content.ReadFromJsonAsync<ApiResponse<List<DnsRecord>>>();
        return result?.Data ?? new List<DnsRecord>();
    }

    private async Task<DnsRecord> CreateCoreDnsRecordAsync(string zone, DnsRecord record)
    {
        var response = await _httpClient.PostAsJsonAsync($"/api/v1/dns/zones/{zone}/records", record);
        response.EnsureSuccessStatusCode();
        var result = await response.Content.ReadFromJsonAsync<ApiResponse<DnsRecord>>();
        return result?.Data ?? record;
    }

    private async Task<DnsRecord> UpdateCoreDnsRecordAsync(string zone, string recordId, DnsRecord record)
    {
        var response = await _httpClient.PutAsJsonAsync($"/api/v1/dns/zones/{zone}/records/{recordId}", record);
        response.EnsureSuccessStatusCode();
        var result = await response.Content.ReadFromJsonAsync<ApiResponse<DnsRecord>>();
        return result?.Data ?? record;
    }

    private async Task DeleteCoreDnsRecordAsync(string zone, string recordId)
    {
        var response = await _httpClient.DeleteAsync($"/api/v1/dns/zones/{zone}/records/{recordId}");
        response.EnsureSuccessStatusCode();
    }

    // ─── Cloudflare ───
    private async Task<List<DnsRecord>> GetCloudflareRecordsAsync(string zone)
    {
        var response = await _httpClient.GetAsync($"/zones/{zone}/dns_records");
        response.EnsureSuccessStatusCode();
        var result = await response.Content.ReadFromJsonAsync<CloudflareResponse>();
        return result?.Result?.Select(r => new DnsRecord
        {
            Id = r.Id,
            Name = r.Name,
            Type = r.Type,
            Content = r.Content,
            Ttl = r.Ttl ?? 300,
            Proxied = r.Proxied ?? false
        }).ToList() ?? new List<DnsRecord>();
    }

    private async Task<DnsRecord> CreateCloudflareRecordAsync(string zone, DnsRecord record)
    {
        var req = new CloudflareRecordRequest
        {
            Type = record.Type,
            Name = record.Name,
            Content = record.Content,
            Ttl = record.Ttl,
            Proxied = record.Proxied
        };
        var response = await _httpClient.PostAsJsonAsync($"/zones/{zone}/dns_records", req);
        response.EnsureSuccessStatusCode();
        var result = await response.Content.ReadFromJsonAsync<CloudflareSingleResponse>();
        record.Id = result?.Result?.Id;
        return record;
    }

    private async Task<DnsRecord> UpdateCloudflareRecordAsync(string zone, string recordId, DnsRecord record)
    {
        var req = new CloudflareRecordRequest
        {
            Type = record.Type,
            Name = record.Name,
            Content = record.Content,
            Ttl = record.Ttl,
            Proxied = record.Proxied
        };
        var response = await _httpClient.PutAsJsonAsync($"/zones/{zone}/dns_records/{recordId}", req);
        response.EnsureSuccessStatusCode();
        return record;
    }

    private async Task DeleteCloudflareRecordAsync(string zone, string recordId)
    {
        var response = await _httpClient.DeleteAsync($"/zones/{zone}/dns_records/{recordId}");
        response.EnsureSuccessStatusCode();
    }

    // ─── Route 53 ───
    private async Task<List<DnsRecord>> GetRoute53RecordsAsync(string zone)
    {
        return new List<DnsRecord>();
    }

    private async Task<DnsRecord> CreateRoute53RecordAsync(string zone, DnsRecord record) => record;
    private async Task<DnsRecord> UpdateRoute53RecordAsync(string zone, string recordId, DnsRecord record) => record;
    private async Task DeleteRoute53RecordAsync(string zone, string recordId) { }

    // ─── Response DTOs ───
    private class ApiResponse<T>
    {
        public bool Success { get; set; }
        public T Data { get; set; }
        public string Error { get; set; }
    }

    private class TechnitiumZoneResponse
    {
        public List<TechnitiumRecord> Records { get; set; }
    }

    private class TechnitiumRecord
    {
        public string Id { get; set; }
        public string Name { get; set; }
        public string Type { get; set; }
        public string Value { get; set; }
        public int Ttl { get; set; }
    }

    private class TechnitiumRecordRequest
    {
        public string Name { get; set; }
        public string Type { get; set; }
        public string Value { get; set; }
        public int Ttl { get; set; }
    }

    private class TechnitiumRecordResponse
    {
        public TechnitiumRecord Record { get; set; }
    }

    private class CloudflareResponse
    {
        public bool Success { get; set; }
        public List<CloudflareRecord> Result { get; set; }
    }

    private class CloudflareRecord
    {
        public string Id { get; set; }
        public string Name { get; set; }
        public string Type { get; set; }
        public string Content { get; set; }
        public int? Ttl { get; set; }
        public bool? Proxied { get; set; }
    }

    private class CloudflareRecordRequest
    {
        public string Type { get; set; }
        public string Name { get; set; }
        public string Content { get; set; }
        public int Ttl { get; set; }
        public bool Proxied { get; set; }
    }

    private class CloudflareSingleResponse
    {
        public bool Success { get; set; }
        public CloudflareRecord Result { get; set; }
    }
}