package dialect

import (
	"strings"
)

func statementParse(content string) (statement *RootStatement, err error) {
	parser := &StatementParser{
		content: strings.Split(content, ""),
	}
	statement, err = parser.parse()
	return
}

type StatementParser struct {
	content       []string
	contentLen    int
	curIndex      int // 当前索引
	curRowStart   int // 当前行开始索引
	curStr        string
	curStatement  Statement
	curParent     Statement
	curRow        int // 当前行
	curCol        int // 当前列
	bracketLevel  int // “{}” 层级
	braceLevel    int // “[]” 层级
	inStringLevel int
	inStringPack  string

	curIf     *IfStatement
	curElseIf *ElseIfStatement
	curElse   *ElseStatement
}

func (this_ *StatementParser) reset() {

	this_.contentLen = len(this_.content)
	this_.curRow = 0
	this_.curCol = 0
	this_.curIndex = 0
	this_.curRowStart = 0
	this_.curStr = ""
	this_.curParent = nil
	this_.curStatement = nil
	this_.bracketLevel = 0
	this_.braceLevel = 0

	this_.inStringLevel = 0
	this_.inStringPack = ""

	this_.curIf = nil
	this_.curElseIf = nil
	this_.curElse = nil
}

func (this_ *StatementParser) parse() (statement *RootStatement, err error) {
	statement = &RootStatement{
		AbstractStatement: &AbstractStatement{},
	}
	this_.reset()
	this_.curParent = statement
	err = this_.parseStr()
	if err != nil {
		return
	}
	return
}

func (this_ *StatementParser) parseStr() (err error) {
	if this_.contentLen <= this_.curIndex {
		if this_.curStr != "" {
			var statements []Statement
			statements, err = parseTextStatement(this_.curStr, this_.curParent)
			if err != nil {
				return
			}
			*this_.curParent.GetChildren() = append(*this_.curParent.GetChildren(), statements...)
		}
		return
	}
	var char = this_.content[this_.curIndex]
	var lastChar string
	if this_.curIndex > 0 {
		lastChar = this_.content[this_.curIndex-1]
	}
	this_.curStr += char

	var stringPackChars = []string{"\"", "'"}
	packCharIndex := StringsIndex(stringPackChars, char)
	if packCharIndex >= 0 {
		// inStringLevel == 0 表示 不在 字符串 包装 中
		if this_.inStringLevel == 0 {
			this_.inStringPack = stringPackChars[packCharIndex]
			// 字符串包装层级 +1
			this_.inStringLevel++
		} else {
			// 如果有转义符号 类似 “\'”，“\"”
			if lastChar == "\\" {
			} else if lastChar == this_.inStringPack {
				// 如果 前一个字符 与字符串包装字符一致
				this_.inStringLevel--
			} else {
				// 字符串包装层级 -1
				this_.inStringLevel--
			}
		}
	}

	if this_.inStringLevel == 0 {
		err = this_.checkStatement()
		if err != nil {
			return
		}
	}
	if char == "\n" {
		this_.curRow++
		this_.curCol = 0
	} else {
		this_.curCol++
	}
	this_.curIndex++
	err = this_.parseStr()
	return
}

func (this_ *StatementParser) checkStatement() (err error) {
	var startIndex int
	var endIndex int
	defer func() {
		if startIndex != endIndex {
			this_.curStr = ""
		}
	}()

	switch this_.curStatement.(type) {
	case *IfStatement:
		if startIndex, endIndex, err = this_.checkElseIfStatement(); err != nil || startIndex != endIndex {
			return
		}
		if startIndex, endIndex, err = this_.checkElseStatement(); err != nil || startIndex != endIndex {
			return
		}
		if startIndex, endIndex, err = this_.checkIfEndStatement(); err != nil || startIndex != endIndex {
			return
		}
		break
	case *ElseIfStatement:
		if startIndex, endIndex, err = this_.checkElseIfStatement(); err != nil || startIndex != endIndex {
			return
		}
		if startIndex, endIndex, err = this_.checkElseStatement(); err != nil || startIndex != endIndex {
			return
		}
		if startIndex, endIndex, err = this_.checkIfEndStatement(); err != nil || startIndex != endIndex {
			return
		}
		break
	case *ElseStatement:
		if startIndex, endIndex, err = this_.checkIfEndStatement(); err != nil || startIndex != endIndex {
			return
		}
		break
	default:
		if startIndex, endIndex, err = this_.checkIfStatement(); err != nil || startIndex != endIndex {
			return
		}
	}

	return
}