package config

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

var (
	once sync.Once
	base string // resolved data base dir
)

// DataDir returns the base directory for data (db.bolt, certs, logs, www, etc).
// Respects DATA_DIR env (absolute or relative). Falls back to "data" relative to CWD.
func DataDir() string {
	once.Do(func() {
		if d := os.Getenv("DATA_DIR"); d != "" {
			base = d
			return
		}
		// default relative to cwd
		wd, err := os.Getwd()
		if err != nil {
			wd = "."
		}
		base = filepath.Join(wd, "data")
	})
	return base
}

// Resolve returns an absolute or relative path under the data dir for the given subpath (e.g. "db.bolt", "certs", "www").
// If the corresponding *_DIR env is set it is used as base instead.
func Resolve(sub string) string {
	// Allow per-subdir override e.g. CERTS_DIR, WWW_DIR, LOGS_DIR, CHALLENGE_DIR
	key := ""
	switch sub {
	case "db.bolt":
		key = "DATA_DIR"
	case "certs", "custom_ssl":
		key = "CERTS_DIR"
	case "logs":
		key = "LOGS_DIR"
	case "letsencrypt-acme-challenge", "challenge":
		key = "CHALLENGE_DIR"
	case "www":
		if d := os.Getenv("WWW_DIR"); d != "" {
			return filepath.Join(d, "") // allow override to point directly
		}
		key = "DATA_DIR"
	case "html":
		if d := os.Getenv("HTML_DIR"); d != "" {
			return filepath.Join(d, "")
		}
		key = "DATA_DIR"
	default:
		key = "DATA_DIR"
	}

	dir := DataDir()
	if key != "" {
		if override := os.Getenv(key); override != "" {
			dir = override
		}
	}
	return filepath.Join(dir, sub)
}

// EnsureDataDirs creates the expected subdirs under the resolved data location (and www inside data by default).
// Also pre-creates the acme-challenge subdir layout that lego webroot + our handler expect.
func EnsureDataDirs() error {
	dirs := []string{
		Resolve(""),
		Resolve("certs"),
		Resolve("logs"),
		Resolve("letsencrypt-acme-challenge"),
		Resolve("www"), // data/www by default
	}
	for _, d := range dirs {
		if err := os.MkdirAll(d, 0o755); err != nil {
			return err
		}
	}
	// full layout for http-01 challenges written by lego
	acme := filepath.Join(Resolve("letsencrypt-acme-challenge"), ".well-known", "acme-challenge")
	if err := os.MkdirAll(acme, 0o755); err != nil {
		return err
	}
	return nil
}

// ResetForTest clears the cached data dir (sync.Once) so tests can change
// DATA_DIR / *_DIR envs via t.Setenv and observe fresh resolution.
// Call at the start of such tests. This is the supported way to make
// config testable without globals leaking across tests.
func ResetForTest() {
	once = sync.Once{}
	base = ""
}

// IsDevelopment reports whether PROXY_MODE=development (or "dev").
// Defaults to false (production mode).
// When true, all letsencrypt certs use self-signed test certs (via the cert manager's
// issueTestCert path). No domain tricks (.localtest etc.) are used. In production
// (default) real LE issuance is always attempted.
func IsDevelopment() bool {
	mode := strings.ToLower(os.Getenv("PROXY_MODE"))
	return mode == "development" || mode == "dev"
}