package nexara

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"mime/multipart"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/postmet/transcribe/internal/models"
)

type Client struct {
	apiURL     string
	apiKey     string
	model      string
	httpClient *http.Client
}

func New(baseURL, apiKey, model string, timeout time.Duration) *Client {
	baseURL = strings.TrimRight(baseURL, "/")
	return &Client{
		apiURL: baseURL + "/api/v1/audio/transcriptions",
		apiKey: apiKey,
		model:  model,
		httpClient: &http.Client{
			Timeout: timeout,
		},
	}
}

func (c *Client) TranscribeFile(ctx context.Context, path string) (text, language string, segments []models.Segment, err error) {
	f, err := os.Open(path)
	if err != nil {
		return "", "", nil, fmt.Errorf("open file: %w", err)
	}
	defer f.Close()

	body := &bytes.Buffer{}
	writer := multipart.NewWriter(body)
	part, err := writer.CreateFormFile("file", filepath.Base(path))
	if err != nil {
		return "", "", nil, err
	}
	if _, err := io.Copy(part, f); err != nil {
		return "", "", nil, err
	}
	if c.model != "" {
		if err := writer.WriteField("model", c.model); err != nil {
			return "", "", nil, err
		}
	}
	if err := writer.WriteField("response_format", "json"); err != nil {
		return "", "", nil, err
	}
	if err := writer.Close(); err != nil {
		return "", "", nil, err
	}

	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.apiURL, body)
	if err != nil {
		return "", "", nil, err
	}
	req.Header.Set("Content-Type", writer.FormDataContentType())
	req.Header.Set("Authorization", "Bearer "+c.apiKey)

	resp, err := c.httpClient.Do(req)
	if err != nil {
		return "", "", nil, fmt.Errorf("request: %w", err)
	}
	defer resp.Body.Close()

	respBody, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", "", nil, err
	}
	if resp.StatusCode != http.StatusOK {
		return "", "", nil, fmt.Errorf("status %d: %s", resp.StatusCode, string(respBody))
	}

	var raw map[string]any
	if err := json.Unmarshal(respBody, &raw); err != nil {
		return "", "", nil, fmt.Errorf("parse: %w", err)
	}
	if t, ok := raw["text"].(string); ok {
		text = t
	}
	if lang, ok := raw["language"].(string); ok {
		language = lang
	}
	if segs, ok := raw["segments"].([]any); ok {
		for _, s := range segs {
			m, ok := s.(map[string]any)
			if !ok {
				continue
			}
			var seg models.Segment
			if v, ok := m["start"].(float64); ok {
				seg.Start = v
			}
			if v, ok := m["end"].(float64); ok {
				seg.End = v
			}
			if v, ok := m["text"].(string); ok {
				seg.Text = v
			}
			segments = append(segments, seg)
		}
	}
	return text, language, segments, nil
}