package controllers

import (
	"bufio"
	"bytes"
	"encoding/json"
	"fmt"
	"net/http"
	"strings"
	"time"

	"github.com/gofiber/fiber/v2"
	"github.com/sujit-baniya/fiber-boilerplate/pkg/models"
)

type DataIa struct {
	Prompt string `json:"prompt"`
	Model  string `json:"model"`
	Stream bool   `json:"stream"`
}

type respuestaOllama struct {
	Response string `json:"response"`
	Done     bool   `json:"done"`
}

func GeneraTextoStream(c *fiber.Ctx) error {
	var data DataIa
	if err := c.BodyParser(&data); err != nil {
		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "Datos inválidos"})
	}
	data.Stream = true

	config, err := models.GetAiConfigForService("ia")
	if err != nil {
		return c.Status(fiber.StatusServiceUnavailable).JSON(fiber.Map{
			"error": "No hay configuración de IA activa. Configura una en /app/ai-config",
		})
	}

	if data.Model == "" {
		data.Model = config.ModelName
	}
	if data.Model == "" {
		data.Model = "gemma3:1b"
	}

	// Usar endpoint nativo de Ollama (/api/generate), no OpenAI compat (/v1/...)
	baseURL := strings.TrimSuffix(strings.TrimRight(config.BaseURL, "/"), "/v1")
	endpoint := baseURL + "/api/generate"

	jsonData, _ := json.Marshal(data)
	req, err := http.NewRequest("POST", endpoint, bytes.NewBuffer(jsonData))
	if err != nil {
		return err
	}
	req.Header.Set("Content-Type", "application/json")
	// Sin auth para red interna; api_key como token para URL pública
	if config.ApiKey != "" && config.ApiKey != "ollama" {
		req.SetBasicAuth("ollama", config.ApiKey)
	}

	client := &http.Client{Timeout: 120 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return c.Status(fiber.StatusBadGateway).JSON(fiber.Map{"error": err.Error()})
	}

	c.Set("Content-Type", "text/plain; charset=utf-8")
	c.Set("Cache-Control", "no-cache")
	c.Set("Connection", "keep-alive")

	c.Context().SetBodyStreamWriter(func(w *bufio.Writer) {
		defer resp.Body.Close()
		scanner := bufio.NewScanner(resp.Body)
		for scanner.Scan() {
			line := scanner.Bytes()
			if len(line) == 0 {
				continue
			}
			var msg respuestaOllama
			if err := json.Unmarshal(line, &msg); err != nil {
				continue
			}
			if msg.Response != "" {
				fmt.Fprint(w, msg.Response)
				w.Flush()
			}
			if msg.Done {
				break
			}
		}
	})

	return nil
}