using System.Net;
using System.Net.Http.Headers;
using System.Text;
using System.Text.Json;
using System.Text.Json.Serialization;
using Microsoft.Azure.Functions.Worker;
using Microsoft.Azure.Functions.Worker.Http;
using Microsoft.Extensions.Logging;

namespace CognitiveClarity.api
{
    public class AnalysisRequest
    {
        [JsonPropertyName("turnContext")]
        public string TurnContext { get; set; } = string.Empty;

        [JsonPropertyName("scenarioTitle")]
        public string ScenarioTitle { get; set; } = string.Empty;

        [JsonPropertyName("scenarioDescription")]
        public string ScenarioDescription { get; set; } = string.Empty;

        [JsonPropertyName("cbtFocus")]
        public List<string> CBTFocus { get; set; } = new();

        [JsonPropertyName("model")]
        public string Model { get; set; } = "google/gemini-3.8-flash";
    }

    public class AnalysisFunction
    {
        private readonly ILogger _logger;
        private readonly IHttpClientFactory _httpClientFactory;

        public AnalysisFunction(ILoggerFactory loggerFactory, IHttpClientFactory httpClientFactory)
        {
            _logger = loggerFactory.CreateLogger<AnalysisFunction>();
            _httpClientFactory = httpClientFactory;
        }

        [Function("ClinicalAnalysis")]
        public async Task<HttpResponseData> Run(
            [HttpTrigger(AuthorizationLevel.Anonymous, "post", Route = "analysis")] HttpRequestData req)
        {
            _logger.LogInformation("C# HTTP trigger function processed a clinical analysis request via OpenRouter.");

            var requestBody = await new StreamReader(req.Body).ReadToEndAsync();
            var data = JsonSerializer.Deserialize<AnalysisRequest>(requestBody);

            if (data == null || string.IsNullOrWhiteSpace(data.TurnContext))
            {
                var badResponse = req.CreateResponse(HttpStatusCode.BadRequest);
                await badResponse.WriteStringAsync("Please provide turnContext in the request body");
                return badResponse;
            }

            var apiKey = System.Environment.GetEnvironmentVariable("OPENROUTER_API_KEY");
            if (string.IsNullOrEmpty(apiKey))
            {
                _logger.LogError("OPENROUTER_API_KEY is missing from environment variables.");
                return req.CreateResponse(HttpStatusCode.InternalServerError);
            }

            var systemAnalysisPrompt = $@"You are a master clinical psychologist specializing in Cognitive Behavioral Therapy (CBT).
You are supervising an interactive CBT simulation.
SCENARIO: {data.ScenarioTitle} - {data.ScenarioDescription}
FOCUS AREAS: {string.Join(", ", data.CBTFocus)}

Return ONLY a valid JSON object matching this schema:
{{
  ""analysis"": {{
    ""distortions"": [""string""],
    ""isAdaptive"": boolean,
    ""evidence"": ""string""
  }},
  ""rating"": {{
    ""score"": number (1-5),
    ""reason"": ""string""
  }},
  ""suggestions"": {{
    ""alternativeThought"": ""string"",
    ""behavioralStep"": ""string""
  }}
}}";

            var payload = new
            {
                model = string.IsNullOrEmpty(data.Model) ? "google/gemini-3.8-flash" : data.Model,
                messages = new object[]
                {
                    new { role = "system", content = systemAnalysisPrompt },
                    new { role = "user", content = data.TurnContext }
                },
                response_format = new { type = "json_object" },
                temperature = 0.2
            };

            try
            {
                var client = _httpClientFactory.CreateClient();
                client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);
                client.DefaultRequestHeaders.Add("HTTP-Referer", "https://cognitive-clarity.app");
                client.DefaultRequestHeaders.Add("X-Title", "Cognitive Clarity");

                var content = new StringContent(JsonSerializer.Serialize(payload), Encoding.UTF8, "application/json");
                var response = await client.PostAsync("https://openrouter.ai/api/v1/chat/completions", content);

                if (!response.IsSuccessStatusCode)
                {
                    var errText = await response.Content.ReadAsStringAsync();
                    _logger.LogError("OpenRouter returned error {Status}: {Error}", response.StatusCode, errText);
                    var errResponse = req.CreateResponse(response.StatusCode);
                    await errResponse.WriteStringAsync(errText);
                    return errResponse;
                }

                var resJson = await response.Content.ReadAsStringAsync();
                using var doc = JsonDocument.Parse(resJson);
                var rawResult = doc.RootElement
                    .GetProperty("choices")[0]
                    .GetProperty("message")
                    .GetProperty("content")
                    .GetString() ?? "{}";

                var successResponse = req.CreateResponse(HttpStatusCode.OK);
                successResponse.Headers.Add("Content-Type", "application/json");
                await successResponse.WriteStringAsync(rawResult);
                return successResponse;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to generate analysis via OpenRouter API.");
                var errorResponse = req.CreateResponse(HttpStatusCode.InternalServerError);
                await errorResponse.WriteStringAsync("Error communicating with OpenRouter API.");
                return errorResponse;
            }
        }
    }
}