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
	TrustedProxies     string
	Rules              []string
	Log                string
	FileRemove         int
	ImagePreview       bool
	FolderDownload     string
	SessionTimeout     int
	JWTSecret          string
	HTMLTitle          string
	HTMLNotice         string
	UserFile           string
	UserHome           string
	ThumbnailMaxSize   int64
	ThumbnailMaxPixels int64
	ZipMaxSize         int64
	ZipMaxFiles        int
	UploadMaxSize      int64
	UploadMaxTotalSize int64
	UploadMaxFiles     int
	SearchMaxResults   int
	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", ThumbnailMaxSize: 32 << 20, ThumbnailMaxPixels: 40_000_000, ZipMaxSize: 2 << 30, ZipMaxFiles: 5000, UploadMaxSize: 2 << 30, UploadMaxTotalSize: 4 << 30, UploadMaxFiles: 100, SearchMaxResults: 500}
}

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 "trusted-proxies":
			c.TrustedProxies = 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 "jwt.secret":
			c.JWTSecret = val
		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 "thumbnail.max-size":
			if n, e := strconv.ParseInt(val, 10, 64); e == nil && n >= 0 {
				c.ThumbnailMaxSize = n
			}
		case "thumbnail.max-pixels":
			if n, e := strconv.ParseInt(val, 10, 64); e == nil && n >= 0 {
				c.ThumbnailMaxPixels = n
			}
		case "zip.max-size":
			if n, e := strconv.ParseInt(val, 10, 64); e == nil && n >= 0 {
				c.ZipMaxSize = n
			}
		case "zip.max-files":
			if n, e := strconv.Atoi(val); e == nil && n >= 0 {
				c.ZipMaxFiles = n
			}
		case "upload.max-size":
			if n, e := strconv.ParseInt(val, 10, 64); e == nil && n >= 0 {
				c.UploadMaxSize = n
			}
		case "upload.max-total-size":
			if n, e := strconv.ParseInt(val, 10, 64); e == nil && n >= 0 {
				c.UploadMaxTotalSize = n
			}
		case "upload.max-files":
			if n, e := strconv.Atoi(val); e == nil && n >= 0 {
				c.UploadMaxFiles = n
			}
		case "search.max-results":
			if n, e := strconv.Atoi(val); e == nil && n >= 0 {
				c.SearchMaxResults = n
			}
		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
}