import type { CodeStatement, Parse, SimpleToken } from '../types'

import { createProgramNode } from '../utils'

export class Parser {

ast = createProgramNode()

current = 0

constructor(public tokens: SimpleToken[], public parsers: Parse[] = []) {

}

walk() {

const token = this.tokens[this.current]

if (token.type === 'code') {

this.current++

return {

type: 'CodeStatement',

value: token.value,

start: token.start,

end: token.end,

} as CodeStatement

}

for (const parser of this.parsers) {

const node = parser.bind(this)(token)

if (node) {

return {

comment: token.comment,

start: token.start,

end: token.end,

...node,

}

}

}

throw new Error(`Parser: Unknown token type: ${token.type}`)

}

private parse() {

while (this.current < this.tokens.length)

this.ast.body.push(this.walk())

return this.ast

}

static parse(tokens: SimpleToken[], parsers: Parse[] = []) {

const parser = new Parser(tokens, parsers)

return parser.parse()

}

}