// Package newproject scaffolds a new Arduino sketch directory.
package newproject

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

	"gitlab.hive-brain.de/MDietermann/Archduino/internal/config"
	"gitlab.hive-brain.de/MDietermann/Archduino/internal/platform"
)

//go:embed assets
var assetsFS embed.FS

const clangdContent = `CompileFlags:
  Add:
    - -xc++
    - -std=c++17
`

// Run creates a new Arduino project directory. It errors if the project
// directory already exists, if the board is unknown, or if the project name
// contains a path separator.
func Run(cfg config.Config, project, board string) error {
	if project == "" {
		return fmt.Errorf("project name required")
	}
	if strings.ContainsAny(project, "/\\") || strings.HasPrefix(project, ".") {
		return fmt.Errorf("invalid project name %q", project)
	}

	var b *config.Board
	var valid []string
	for i := range cfg.Scaffolding.Boards {
		bp := &cfg.Scaffolding.Boards[i]
		valid = append(valid, bp.Name)
		if bp.Name == board {
			b = bp
		}
	}
	if b == nil {
		return fmt.Errorf("unknown board %q; valid: %s", board, strings.Join(valid, ", "))
	}

	if _, err := os.Stat(project); err == nil {
		return fmt.Errorf("project directory %q already exists", project)
	}
	if err := os.MkdirAll(project, 0o755); err != nil {
		return err
	}

	// Pick .ino template: try <template>.ino, else default.ino.
	inoData, err := assetsFS.ReadFile(filepath.Join("assets", b.Template+".ino"))
	if err != nil {
		inoData, err = assetsFS.ReadFile("assets/default.ino")
		if err != nil {
			return err
		}
	}
	if err := platform.WriteUserFile(filepath.Join(project, project+".ino"), inoData, 0o644); err != nil {
		return err
	}

	sketch := fmt.Sprintf("default_fqbn: %s\ndefault_port: auto\n", b.FQBN)
	if err := platform.WriteUserFile(filepath.Join(project, "sketch.yaml"), []byte(sketch), 0o644); err != nil {
		return err
	}
	if err := platform.WriteUserFile(filepath.Join(project, ".clangd"), []byte(clangdContent), 0o644); err != nil {
		return err
	}
	return nil
}