package config

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

type AccountConfig struct {
	Username string
	Password string
	Role     string
	Default  string
	None     []string
	Read     []string
	Write    []string
	Delete   []string
}

type Config struct {
	Path           []string
	Port           int
	Allow          string
	Rules          []string
	Log            string
	FileRemove     int
	ImagePreview   bool
	FolderDownload string
	SessionTimeout int
	HTMLTitle      string
	HTMLNotice     string
	UserFile       string
	UserHome       string
	SSLCert        string
	SSLKey         string
	Accounts       []AccountConfig
}

func Default() Config {
	return Config{Path: []string{"."}, Port: 80, FileRemove: 1, ImagePreview: true, FolderDownload: "enable", SessionTimeout: 30, UserHome: "users"}
}

func Load(path string) (Config, error) {
	c := Default()
	f, err := os.Open(path)
	if err != nil {
		return c, err
	}
	defer f.Close()
	s := bufio.NewScanner(f)
	var section *AccountConfig
	for s.Scan() {
		line := strings.TrimSpace(s.Text())
		if line == "" || strings.HasPrefix(line, ";") || strings.HasPrefix(line, "#") {
			continue
		}
		if strings.HasPrefix(line, "[") && strings.HasSuffix(line, "]") {
			name := strings.TrimSpace(line[1 : len(line)-1])
			if name != "" {
				c.Accounts = append(c.Accounts, AccountConfig{Username: name})
				section = &c.Accounts[len(c.Accounts)-1]
			} else {
				section = nil
			}
			continue
		}
		i := strings.IndexByte(line, '=')
		if i < 0 {
			continue
		}
		key, val := strings.TrimSpace(line[:i]), strings.TrimSpace(line[i+1:])
		val = strings.Trim(val, "\\\"")
		if section != nil {
			switch strings.ToLower(key) {
			case "password":
				section.Password = val
			case "role":
				section.Role = strings.ToLower(val)
			case "rule.default":
				section.Default = val
			case "rule.none":
				section.None = appendNonEmpty(section.None, val)
			case "rule.r":
				section.Read = appendNonEmpty(section.Read, val)
			case "rule.w":
				section.Write = appendNonEmpty(section.Write, val)
			case "rule.d":
				section.Delete = appendNonEmpty(section.Delete, val)
			}
			continue
		}
		switch strings.ToLower(key) {
		case "path":
			c.Path = splitPath(val)
		case "port":
			if n, e := strconv.Atoi(val); e == nil && n > 0 && n < 65536 {
				c.Port = n
			}
		case "allow":
			c.Allow = val
		case "rule":
			if val != "" {
				c.Rules = append(c.Rules, val)
			}
		case "log":
			c.Log = val
		case "file.remove":
			if n, e := strconv.Atoi(val); e == nil {
				c.FileRemove = n
			}
		case "image.preview":
			c.ImagePreview = parseBool(val, c.ImagePreview)
		case "folder.download":
			c.FolderDownload = strings.ToLower(val)
		case "folder.leaf.download":
			if parseBool(val, false) {
				c.FolderDownload = "leaf"
			}
		case "session.timeout":
			if n, e := strconv.Atoi(val); e == nil && n > 0 {
				c.SessionTimeout = n
			}
		case "html.title":
			c.HTMLTitle = val
		case "html.notice":
			c.HTMLNotice = val
		case "user.file":
			c.UserFile = val
		case "user.home":
			c.UserHome = strings.Trim(val, "/")
		case "ssl.cert":
			c.SSLCert = val
		case "ssl.key":
			c.SSLKey = val
		}
	}
	if err := s.Err(); err != nil {
		return c, err
	}
	return c, nil
}

func splitPath(v string) []string {
	var out []string
	for _, p := range strings.Split(v, "|") {
		p = strings.TrimSpace(strings.Trim(p, "\\\""))
		if p != "" {
			out = append(out, p)
		}
	}
	if len(out) == 0 {
		return []string{"."}
	}
	return out
}

func parseBool(v string, d bool) bool {
	switch strings.ToLower(strings.TrimSpace(v)) {
	case "true", "1", "yes", "on":
		return true
	case "false", "0", "no", "off":
		return false
	}
	return d
}
func (c Config) Validate() error {
	if len(c.Path) == 0 {
		return fmt.Errorf("path is empty")
	}
	if c.Port < 1 || c.Port > 65535 {
		return fmt.Errorf("invalid port")
	}
	return nil
}

func appendNonEmpty(dst []string, value string) []string {
	for _, item := range strings.Split(value, "|") {
		item = strings.TrimSpace(item)
		if item != "" {
			dst = append(dst, item)
		}
	}
	return dst
}