package api

import (
	"encoding/json"
	"io/ioutil"
	"net/http"
	"path/filepath"
	"strconv"

	"github.com/smjklake/glancr/internal/tokenizer"
)

type API struct {
	tokenizer *tokenizer.Tokenizer
}

func NewAPI() *API {
	return &API{
		tokenizer: tokenizer.NewTokenizer(),
	}
}

// GET /api/file?path=example.go&start=1&end=100
func (a *API) HandleFile(w http.ResponseWriter, r *http.Request) {
	filePath := r.URL.Query().Get("path")
	startLine := r.URL.Query().Get("start")
	endLine := r.URL.Query().Get("end")

	// Read file
	content, err := ioutil.ReadFile(filePath)
	if err != nil {
		http.Error(w, "File not found", http.StatusNotFound)
		return
	}

	// Detect language from extension
	language := detectLanguage(filepath.Ext(filePath))

	// Tokenize
	doc := a.tokenizer.TokenizeDocument(string(content), language)

	// Handle range requests for virtual scrolling
	if startLine != "" && endLine != "" {
		start, _ := strconv.Atoi(startLine)
		end, _ := strconv.Atoi(endLine)

		if start > 0 && end <= len(doc.Lines) {
			doc.Lines = doc.Lines[start-1 : end]
		}
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(doc)
}

func detectLanguage(ext string) string {
	switch ext {
	case ".go":
		return "go"
	case ".js", ".jsx":
		return "javascript"
	case ".ts", ".tsx":
		return "javascript" // Can add typescript later
	case ".md":
		return "markdown"
	default:
		return "text"
	}
}