package ingestion

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"
)

type Result struct {
	Title  string
	Body   string
	Format string
}

var parsers = map[string]func(string) (string, error){
	".md":       ParseMarkdown,
	".markdown": ParseMarkdown,
	".pdf":      ParsePDF,
	".docx":     ParseDOCX,
}

func ParseFile(path string) (Result, error) {
	ext := strings.ToLower(filepath.Ext(path))
	parse, ok := parsers[ext]
	if !ok {
		return Result{}, fmt.Errorf("unsupported file format: %s", ext)
	}

	body, err := parse(path)
	if err != nil {
		return Result{}, fmt.Errorf("parse %s: %w", ext, err)
	}

	title := strings.TrimSuffix(filepath.Base(path), ext)
	return Result{
		Title:  title,
		Body:   strings.TrimSpace(body),
		Format: ext[1:],
	}, nil
}

func IsSupported(path string) bool {
	ext := strings.ToLower(filepath.Ext(path))
	_, ok := parsers[ext]
	return ok
}

func SupportedExtensions() []string {
	exts := make([]string, 0, len(parsers))
	for ext := range parsers {
		exts = append(exts, ext)
	}
	return exts
}

func ParseFromBytes(filename string, data []byte) (Result, error) {
	safe := filepath.Base(filename)
	if safe == "." || safe == string(filepath.Separator) {
		return Result{}, fmt.Errorf("invalid filename: %q", filename)
	}

	tmpDir, err := os.MkdirTemp("", "ingestion-*")
	if err != nil {
		return Result{}, fmt.Errorf("create temp dir: %w", err)
	}
	defer os.RemoveAll(tmpDir)

	tmpPath := filepath.Join(tmpDir, safe)
	if err := os.WriteFile(tmpPath, data, 0644); err != nil {
		return Result{}, fmt.Errorf("write temp file: %w", err)
	}

	return ParseFile(tmpPath)
}