package main

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"os"
	"strconv"
	"strings"
	"time"

	"github.com/sirupsen/logrus"
)

// --- OllamaClient implementation ---

type OllamaClient struct {
	APIKey         string
	BaseURL        string
	Model          string
	EmbeddingModel string
	Repo           ChatRepositoryAPI
}

func NewOllamaClient(apiKey, baseURL, model string, repo ChatRepositoryAPI) *OllamaClient {
	return &OllamaClient{APIKey: apiKey, BaseURL: baseURL, Model: model, Repo: repo}
}

func (llm *OllamaClient) ExtractKeywords(ctx context.Context, message string) (map[string]interface{}, error) {
	_, parsed, err := llm.ExtractKeywordsRaw(ctx, message)
	return parsed, err
}

func (llm *OllamaClient) ExtractKeywordsRaw(ctx context.Context, message string) (string, map[string]interface{}, error) {
	prompt, err := renderPrompt(appConfig.LLM.ExtractKeywordsPrompt, map[string]string{"Message": message})
	if err != nil {
		logrus.WithError(err).Error("[CONFIG] Failed to render ExtractKeywords prompt")
		return "", nil, err
	}
	logrus.WithField("prompt", prompt).Info("[LLM] ExtractKeywords prompt")

	// Use the utility function instead of inline format definition
	format := GetExtractKeywordsFormat()

	resp, err := llm.ollamaCompletion(ctx, prompt, format)
	logrus.WithFields(logrus.Fields{"response": resp, "err": err}).Info("[LLM] ExtractKeywords response")
	if err != nil {
		return resp, nil, err
	}
	var result map[string]interface{}
	if err := json.Unmarshal([]byte(resp), &result); err != nil {
		return resp, nil, err
	}
	return resp, result, nil
}

func (llm *OllamaClient) DisambiguateBestMatch(ctx context.Context, message string, candidates []Visit) (string, error) {
	_, vr, err := llm.DisambiguateBestMatchRaw(ctx, message, candidates)
	return vr, err
}

func (llm *OllamaClient) DisambiguateBestMatchRaw(ctx context.Context, message string, candidates []Visit) (string, string, error) {
	// Use the utility function instead of inline format definition
	format := GetDisambiguateFormat()

	entries, _ := json.Marshal(candidates)
	prompt, err := renderPrompt(appConfig.LLM.DisambiguatePrompt, map[string]string{"Entries": string(entries), "Message": message})
	if err != nil {
		logrus.WithError(err).Error("[CONFIG] Failed to render Disambiguate prompt")
		return "", "", err
	}
	logrus.WithField("prompt", prompt).Info("[LLM] DisambiguateBestMatch prompt")
	resp, err := llm.ollamaCompletion(ctx, prompt, format)
	logrus.WithFields(logrus.Fields{"response": resp, "err": err}).Info("[LLM] DisambiguateBestMatch response")
	if err != nil {
		return resp, "", err
	}
	var parsed map[string]string
	if err := json.Unmarshal([]byte(resp), &parsed); err != nil {
		return resp, "", fmt.Errorf("failed to unmarshal disambiguation response: %w", err)
	}
	visitReason := strings.TrimSpace(parsed["visitReason"])
	if visitReason == "" {
		return resp, "", fmt.Errorf("visitReason not found in response")
	}
	return resp, visitReason, nil
}

func (llm *OllamaClient) ollamaCompletion(ctx context.Context, prompt string, format map[string]interface{}) (string, error) {
	apiURL := llm.BaseURL
	if apiURL == "" {
		apiURL = "http://localhost:11434/api/chat"
	}

	messages := []map[string]string{{"role": "user", "content": prompt}}
	//if os.Getenv("DISABLE_THINK") == "1" {
	// System message to suppress chain-of-thought style outputs.
	messages = append([]map[string]string{{
		"role":    "system",
		"content": "You are a concise assistant. Output ONLY the final answer requested by the user. Do not include reasoning, analysis, or <think> tags.",
	}}, messages...)
	//}

	body := map[string]interface{}{
		"model":    llm.Model,
		"messages": messages,
		"stream":   false,
		"format":   format,
	}

	// Optional: Add a stop sequence to prevent <think> tags if they appear
	if os.Getenv("DISABLE_THINK") == "1" {
		body["options"] = map[string]interface{}{"stop": []string{"<think>"}}
	}

	jsonBody, _ := json.Marshal(body)
	req, _ := http.NewRequestWithContext(ctx, http.MethodPost, apiURL, bytes.NewBuffer(jsonBody))
	if llm.APIKey != "" {
		req.Header.Set("Authorization", "Bearer "+llm.APIKey)
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Accept", "application/json")
	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()
	raw, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", err
	}
	var ollama struct {
		Message struct {
			Content string `json:"content"`
		} `json:"message"`
		Error string `json:"error"`
	}
	if err := json.Unmarshal(raw, &ollama); err == nil && ollama.Message.Content != "" {
		return ollama.Message.Content, nil
	}
	if ollama.Error != "" {
		return "", fmt.Errorf("provider error: %s", ollama.Error)
	}
	return "", fmt.Errorf("unrecognized LLM response format: %.200s", string(raw))
}

func normalizeOllamaHost(raw string) string {
	if raw == "" {
		return "http://localhost:11434"
	}
	// strip trailing /api/* paths if user provided full endpoint
	lower := strings.ToLower(raw)
	for _, seg := range []string{"/api/chat", "/api/embeddings", "/api/generate"} {
		if strings.HasSuffix(lower, seg) {
			return raw[:len(raw)-len(seg)]
		}
	}
	return raw
}

func (llm *OllamaClient) GetEmbeddings(ctx context.Context, input string) ([]float64, error) {
	host := normalizeOllamaHost(llm.BaseURL)
	apiURL := host + "/api/embeddings"
	modelName := llm.Model
	if llm.EmbeddingModel != "" {
		modelName = llm.EmbeddingModel
	}
	// retry parameters (env override OLLAMA_EMBED_ATTEMPTS)
	maxAttempts := 5
	if v := os.Getenv("OLLAMA_EMBED_ATTEMPTS"); v != "" {
		if n, err := strconv.Atoi(v); err == nil && n > 0 && n < 20 {
			maxAttempts = n
		}
	}
	baseBackoff := 300 * time.Millisecond
	var lastErr error
	for attempt := 0; attempt < maxAttempts; attempt++ {
		select {
		case <-ctx.Done():
			return nil, ctx.Err()
		default:
		}
		body := map[string]interface{}{
			"model":  modelName,
			"prompt": input,
		}
		jsonBody, _ := json.Marshal(body)
		req, _ := http.NewRequestWithContext(ctx, http.MethodPost, apiURL, bytes.NewBuffer(jsonBody))
		if llm.APIKey != "" {
			req.Header.Set("Authorization", "Bearer "+llm.APIKey)
		}
		req.Header.Set("Content-Type", "application/json")
		req.Header.Set("Accept", "application/json")
		resp, err := (&http.Client{}).Do(req)
		if err != nil {
			lastErr = err
			logrus.WithError(err).Warnf("[Ollama] embeddings request attempt=%d failed", attempt+1)
		} else {
			raw, rerr := io.ReadAll(resp.Body)
			resp.Body.Close()
			if rerr != nil {
				lastErr = rerr
			} else {
				var generic map[string]json.RawMessage
				if jerr := json.Unmarshal(raw, &generic); jerr != nil {
					lastErr = fmt.Errorf("unrecognized response (parse): %w", jerr)
				} else if embRaw, ok := generic["embedding"]; ok && len(embRaw) > 0 {
					var emb []float64
					if jerr := json.Unmarshal(embRaw, &emb); jerr != nil {
						lastErr = fmt.Errorf("failed to decode embedding: %w", jerr)
					} else if len(emb) == 0 {
						lastErr = fmt.Errorf("empty embedding returned")
					} else {
						return emb, nil
					}
				} else if drRaw, ok := generic["done_reason"]; ok {
					var reason string
					_ = json.Unmarshal(drRaw, &reason)
					if reason == "load" { // transient model loading state
						lastErr = fmt.Errorf("model loading")
					} else {
						lastErr = fmt.Errorf("unexpected done_reason=%s", reason)
					}
				} else if errRaw, ok := generic["error"]; ok {
					var errMsg string
					_ = json.Unmarshal(errRaw, &errMsg)
					if errMsg != "" {
						lastErr = fmt.Errorf("embedding error: %s", errMsg)
					} else {
						lastErr = fmt.Errorf("embedding error (empty message)")
					}
				} else {
					lastErr = fmt.Errorf("unrecognized embedding response: %.200s", string(raw))
				}
			}
		}
		if lastErr == nil {
			break
		}
		// backoff if not last attempt
		if attempt < maxAttempts-1 {
			delay := baseBackoff << attempt
			if strings.Contains(strings.ToLower(lastErr.Error()), "model loading") {
				delay += 1 * time.Second
			}
			time.Sleep(delay)
		}
	}
	if lastErr == nil {
		lastErr = fmt.Errorf("embedding retrieval failed with no error info")
	}
	return nil, lastErr
}

func (llm *OllamaClient) TranslateToEnglish(ctx context.Context, message string) (string, error) {
	prompt, err := renderPrompt(appConfig.LLM.TranslatePrompt, map[string]string{"Message": message})
	if err != nil {
		logrus.WithError(err).Error("[CONFIG] Failed to render Translate prompt")
		return "", err
	}
	logrus.WithField("prompt", prompt).Info("[LLM] TranslateToEnglish prompt")

	resp, err := llm.ollamaCompletion(ctx, prompt, nil)
	logrus.WithFields(logrus.Fields{"response": resp, "err": err}).Info("[LLM] TranslateToEnglish response")
	if err != nil {
		return resp, err
	}
	return strings.TrimSpace(resp), nil
}