package ai

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
)

type ollamaProvider struct {
	endpoint string
	model    string
	client   *http.Client
}

func newOllama(endpoint, model string) *ollamaProvider {
	if endpoint == "" {
		endpoint = "http://ollama:11434"
	}
	if model == "" {
		model = "llama3"
	}
	return &ollamaProvider{
		endpoint: endpoint,
		model:    model,
		client:   &http.Client{},
	}
}

func (p *ollamaProvider) Name() string { return "ollama" }

func (p *ollamaProvider) Summarize(ctx context.Context, prompt string, opts GenOptions) (string, error) {
	numCtx := 32768
	if opts.NumCtx > 0 {
		numCtx = opts.NumCtx
	}
	body := map[string]interface{}{
		"model":  p.model,
		"prompt": prompt,
		"stream": false,
		"think":  opts.Think,
		"options": map[string]interface{}{
			"num_ctx": numCtx,
		},
	}
	b, _ := json.Marshal(body)
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, p.endpoint+"/api/generate", bytes.NewReader(b))
	if err != nil {
		return "", err
	}
	req.Header.Set("Content-Type", "application/json")

	resp, err := p.client.Do(req)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()

	raw, _ := io.ReadAll(resp.Body)
	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("ollama API error %d: %s", resp.StatusCode, raw)
	}

	var result struct {
		Response string `json:"response"`
	}
	if err := json.Unmarshal(raw, &result); err != nil {
		return "", err
	}
	return result.Response, nil
}

func (p *ollamaProvider) ListModels(ctx context.Context) ([]string, error) {
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, p.endpoint+"/api/tags", nil)
	if err != nil {
		return nil, err
	}
	resp, err := p.client.Do(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	raw, _ := io.ReadAll(resp.Body)
	var result struct {
		Models []struct {
			Name string `json:"name"`
		} `json:"models"`
	}
	if err := json.Unmarshal(raw, &result); err != nil {
		return nil, err
	}
	var models []string
	for _, m := range result.Models {
		models = append(models, m.Name)
	}
	return models, nil
}