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 ScenarioRequest
    {
        [JsonPropertyName("prompt")]
        public string Prompt { get; set; } = string.Empty;

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

        [JsonPropertyName("difficulty")]
        public string Difficulty { get; set; } = "Intermediate";

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

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

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

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

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

            if (data == null || (string.IsNullOrWhiteSpace(data.Prompt) && data.SelectedConcepts.Count == 0))
            {
                var badResponse = req.CreateResponse(HttpStatusCode.BadRequest);
                await badResponse.WriteStringAsync("Please pass a prompt or concepts 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 selectedContext = data.SelectedConcepts.Count > 0 
                ? $"Focus specifically on these CBT concepts: {string.Join(", ", data.SelectedConcepts)}."
                : "";

            var systemInstruction = $@"
[CONTEXT]
You are a Clinical CBT Scenario Architect. 
The user requires a structured clinical simulation designed to address specific cognitive distortions and behavioral challenges.
Clinical Focus: {selectedContext}

[TASK]
Transform the user's prompt into a cohesive, structured clinical scenario that sets up a targeted roleplay environment.

[CONSTRAINTS]
- CATEGORIZATION: You MUST categorize the scenario appropriately (Social Anxiety, Workplace, Relationships, or Self-Talk).
- DIFFICULTY CALIBRATION: The requested difficulty is '{data.Difficulty}'.
  - 'Beginner': Low stakes, high support, clear-cut distortions, AI character is cooperative.
  - 'Intermediate': Ambiguous stakes, moderate social friction, subtle distortions, AI character has specific needs.
  - 'Advanced': High emotional triggers, persistent clinical resistance, complex cognitive patterns.
- INTERNAL LOGIC: Provide a detailed ""INTERNAL CBT LOGIC"" section instructing the AI character how to react to the user's progress or cognitive lapses during the future roleplay.
- CHARACTER VOICE: Define a realistic, emotionally consistent voice profile.

[OUTPUT REQUIREMENTS]
Return ONLY a valid JSON object matching this schema:
{{
  ""id"": ""string"",
  ""title"": ""string"",
  ""characterName"": ""string"",
  ""description"": ""string"",
  ""category"": ""Social Anxiety"" | ""Workplace"" | ""Relationships"" | ""Self-Talk"",
  ""difficulty"": ""Beginner"" | ""Intermediate"" | ""Advanced"",
  ""systemInstruction"": ""string"",
  ""initialMessage"": ""string"",
  ""cbtFocus"": [""string""]
}}";

            var promptText = $"Generate a clinical scenario for: {(string.IsNullOrWhiteSpace(data.Prompt) ? "A scenario exploring the chosen CBT concepts." : data.Prompt)}";

            var payload = new
            {
                model = string.IsNullOrEmpty(data.Model) ? "google/gemini-3.8-flash" : data.Model,
                messages = new object[]
                {
                    new { role = "system", content = systemInstruction },
                    new { role = "user", content = promptText }
                },
                response_format = new { type = "json_object" },
                temperature = 0.7
            };

            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 scenarioJson = 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(scenarioJson);
                return successResponse;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Failed to generate scenario via OpenRouter API.");
                var errorResponse = req.CreateResponse(HttpStatusCode.InternalServerError);
                await errorResponse.WriteStringAsync("Error communicating with OpenRouter API.");
                return errorResponse;
            }
        }
    }
}