package token

import (
	"fmt"

	"github.com/suyuan32/goctls/pkg/parser/api/placeholder"
	"github.com/suyuan32/goctls/util"
)

const (
	Syntax        = "syntax"
	Info          = "info"
	Service       = "service"
	Returns       = "returns"
	Any           = "any"
	TypeKeyword   = "type"
	MapKeyword    = "map"
	ImportKeyword = "import"
)

// Type is the type of token.
type Type int

// EofToken is the end of file token.
var EofToken = Token{Type: EOF}

// ErrorToken is the error token.
var ErrorToken = Token{Type: error}

// Token is the token of a rune.
type Token struct {
	Type     Type
	Text     string
	Position Position
}

// Fork forks token for a given Type.
func (t Token) Fork(tp Type) Token {
	return Token{
		Type:     tp,
		Text:     t.Text,
		Position: t.Position,
	}
}

// IsEmptyString returns true if the token is empty string.
func (t Token) IsEmptyString() bool {
	if t.Type != STRING && t.Type != RAW_STRING {
		return false
	}
	text := util.TrimWhiteSpace(t.Text)
	return text == `""` || text == "``"
}

// IsComment returns true if the token is comment.
func (t Token) IsComment() bool {
	return t.IsType(COMMENT)
}

// IsDocument returns true if the token is document.
func (t Token) IsDocument() bool {
	return t.IsType(DOCUMENT)
}

// IsType returns true if the token is the given type.
func (t Token) IsType(tp Type) bool {
	return t.Type == tp
}

// Line returns the line number of the token.
func (t Token) Line() int {
	return t.Position.Line
}

// String returns the string of the token.
func (t Token) String() string {
	if t == ErrorToken {
		return t.Type.String()
	}
	return fmt.Sprintf("%s %s %s", t.Position.String(), t.Type.String(), t.Text)
}

// Valid returns true if the token is valid.
func (t Token) Valid() bool {
	return t.Type != token_bg
}

// IsKeyword returns true if the token is keyword.
func (t Token) IsKeyword() bool {
	return golang_keyword_beg < t.Type && t.Type < golang_keyword_end
}

// IsBaseType returns true if the token is base type.
func (t Token) IsBaseType() bool {
	_, ok := baseDataType[t.Text]
	return ok
}

// IsHttpMethod returns true if the token is http method.
func (t Token) IsHttpMethod() bool {
	_, ok := httpMethod[t.Text]
	return ok
}

// Is returns true if the token text is one of the given list.
func (t Token) Is(text ...string) bool {
	for _, v := range text {
		if t.Text == v {
			return true
		}
	}
	return false
}

const (
	token_bg Type = iota
	error
	ILLEGAL
	EOF
	COMMENT
	DOCUMENT

	literal_beg
	IDENT      // main
	INT        // 123
	DURATION   // 3s,3ms
	STRING     // "abc"
	RAW_STRING // `abc`
	PATH       // `abc`
	KEY        // `abc:`
	literal_end

	operator_beg
	SUB    // -
	MUL    // *
	QUO    // /
	ASSIGN // =

	LPAREN // (
	LBRACK // [
	LBRACE // {
	COMMA  // ,
	DOT    // .

	RPAREN    // )
	RBRACE    // }
	RBRACK    // ]
	SEMICOLON // ;
	COLON     // :
	ELLIPSIS
	operator_end

	golang_keyword_beg
	BREAK
	CASE
	CHAN
	CONST
	CONTINUE

	DEFAULT
	DEFER
	ELSE
	FALLTHROUGH
	FOR

	FUNC
	GO
	GOTO
	IF
	IMPORT

	INTERFACE
	MAP
	PACKAGE
	RANGE
	RETURN

	SELECT
	STRUCT
	SWITCH
	TYPE
	VAR
	golang_keyword_end

	api_keyword_bg
	AT_DOC
	AT_HANDLER
	AT_SERVER
	ANY

	api_keyword_end
	token_end
)

// String returns the string of the token type.
func (t Type) String() string {
	if t >= token_bg && t < token_end {
		return tokens[t]
	}
	return ""
}

var tokens = [...]string{
	ILLEGAL: "ILLEGAL",

	EOF:      "EOF",
	COMMENT:  "COMMENT",
	DOCUMENT: "DOCUMENT",

	IDENT:      "IDENT",
	INT:        "INT",
	DURATION:   "DURATION",
	STRING:     "STRING",
	RAW_STRING: "RAW_STRING",
	PATH:       "PATH",
	KEY:        "KEY",

	SUB:    "-",
	MUL:    "*",
	QUO:    "/",
	ASSIGN: "=",

	LPAREN: "(",
	LBRACK: "[",
	LBRACE: "{",
	COMMA:  ",",
	DOT:    ".",

	RPAREN:    ")",
	RBRACK:    "]",
	RBRACE:    "}",
	SEMICOLON: ";",
	COLON:     ":",
	ELLIPSIS:  "...",

	BREAK:    "break",
	CASE:     "case",
	CHAN:     "chan",
	CONST:    "const",
	CONTINUE: "continue",

	DEFAULT:     "default",
	DEFER:       "defer",
	ELSE:        "else",
	FALLTHROUGH: "fallthrough",
	FOR:         "for",

	FUNC:   "func",
	GO:     "go",
	GOTO:   "goto",
	IF:     "if",
	IMPORT: "import",

	INTERFACE: "interface",
	MAP:       "map",
	PACKAGE:   "package",
	RANGE:     "range",
	RETURN:    "return",

	SELECT: "select",
	STRUCT: "struct",
	SWITCH: "switch",
	TYPE:   "type",
	VAR:    "var",

	AT_DOC:     "@doc",
	AT_HANDLER: "@handler",
	AT_SERVER:  "@server",
	ANY:        "interface{}",
}

// HttpMethods returns the http methods.
var HttpMethods = []interface{}{"get", "head", "post", "put", "patch", "delete", "connect", "options", "trace"}

var httpMethod = map[string]placeholder.Type{
	"get":     placeholder.PlaceHolder,
	"head":    placeholder.PlaceHolder,
	"post":    placeholder.PlaceHolder,
	"put":     placeholder.PlaceHolder,
	"patch":   placeholder.PlaceHolder,
	"delete":  placeholder.PlaceHolder,
	"connect": placeholder.PlaceHolder,
	"options": placeholder.PlaceHolder,
	"trace":   placeholder.PlaceHolder,
}

var keywords = map[string]Type{
	// golang_keyword_bg
	"break":    BREAK,
	"case":     CASE,
	"chan":     CHAN,
	"const":    CONST,
	"continue": CONTINUE,

	"default":     DEFAULT,
	"defer":       DEFER,
	"else":        ELSE,
	"fallthrough": FALLTHROUGH,
	"for":         FOR,

	"func":   FUNC,
	"go":     GO,
	"goto":   GOTO,
	"if":     IF,
	"import": IMPORT,

	"interface": INTERFACE,
	"map":       MAP,
	"package":   PACKAGE,
	"range":     RANGE,
	"return":    RETURN,

	"select": SELECT,
	"struct": STRUCT,
	"switch": SWITCH,
	"type":   TYPE,
	"var":    VAR,
	// golang_keyword_end
}

var baseDataType = map[string]placeholder.Type{
	"bool":       placeholder.PlaceHolder,
	"uint8":      placeholder.PlaceHolder,
	"uint16":     placeholder.PlaceHolder,
	"uint32":     placeholder.PlaceHolder,
	"uint64":     placeholder.PlaceHolder,
	"int8":       placeholder.PlaceHolder,
	"int16":      placeholder.PlaceHolder,
	"int32":      placeholder.PlaceHolder,
	"int64":      placeholder.PlaceHolder,
	"float32":    placeholder.PlaceHolder,
	"float64":    placeholder.PlaceHolder,
	"complex64":  placeholder.PlaceHolder,
	"complex128": placeholder.PlaceHolder,
	"string":     placeholder.PlaceHolder,
	"int":        placeholder.PlaceHolder,
	"uint":       placeholder.PlaceHolder,
	"uintptr":    placeholder.PlaceHolder,
	"byte":       placeholder.PlaceHolder,
	"rune":       placeholder.PlaceHolder,
	"any":        placeholder.PlaceHolder,
}

// LookupKeyword returns the keyword type if the given ident is keyword.
func LookupKeyword(ident string) (Type, bool) {
	tp, ok := keywords[ident]
	return tp, ok
}

// NewIllegalToken returns a new illegal token.
func NewIllegalToken(b rune, pos Position) Token {
	return Token{
		Type:     ILLEGAL,
		Text:     string(b),
		Position: pos,
	}
}
