package main

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

type FileInfo struct {
	Name     string
	Path     string
	RelPath  string
	IsDir    bool
	Size     int64
}

// ListMarkdownFiles returns all .md files in the project directory (non-recursive).
func ListMarkdownFiles(projectDir string) ([]FileInfo, error) {
	entries, err := os.ReadDir(projectDir)
	if err != nil {
		return nil, err
	}

	var files []FileInfo
	for _, e := range entries {
		if e.IsDir() {
			continue
		}
		if !strings.HasSuffix(strings.ToLower(e.Name()), ".md") {
			continue
		}
		info, err := e.Info()
		if err != nil {
			continue
		}
		files = append(files, FileInfo{
			Name:    e.Name(),
			Path:    filepath.Join(projectDir, e.Name()),
			RelPath: e.Name(),
			Size:    info.Size(),
		})
	}

	// Also check docs/ subdirectory
	docsDir := filepath.Join(projectDir, "docs")
	if docEntries, err := os.ReadDir(docsDir); err == nil {
		for _, e := range docEntries {
			if e.IsDir() {
				continue
			}
			if !strings.HasSuffix(strings.ToLower(e.Name()), ".md") {
				continue
			}
			info, err := e.Info()
			if err != nil {
				continue
			}
			files = append(files, FileInfo{
				Name:    "docs/" + e.Name(),
				Path:    filepath.Join(docsDir, e.Name()),
				RelPath: "docs/" + e.Name(),
				Size:    info.Size(),
			})
		}
	}

	sort.Slice(files, func(i, j int) bool {
		return files[i].Name < files[j].Name
	})

	return files, nil
}

// ReadFileContent reads a file and returns its content.
// It validates that the file is within the project directory (path traversal protection).
func ReadFileContent(projectDir, relPath string) (string, error) {
	absPath := filepath.Join(projectDir, relPath)
	absPath = filepath.Clean(absPath)

	// Path traversal protection
	if !strings.HasPrefix(absPath, filepath.Clean(projectDir)) {
		return "", fmt.Errorf("path traversal detected")
	}

	data, err := os.ReadFile(absPath)
	if err != nil {
		return "", err
	}

	return string(data), nil
}

// RenderMarkdownFile reads a markdown file and returns rendered HTML.
func RenderMarkdownFile(projectDir, relPath string) (string, error) {
	content, err := ReadFileContent(projectDir, relPath)
	if err != nil {
		return "", err
	}

	return RenderMD(content), nil
}