//e.g., 
// {
//     Text: [
//       'This is a test',
//       { Text: [Array] },
//       { Text: [Array] },
//       { Text: [Array] }
//     ]
//   }


export type Text = string | { Text: string[] } | Array<string | { Text: string[] }>

export interface DocumentConstructor {
    Text?: Array<string | { Text: string[] }> | string | { Text: string[] }
}

// documents contain text and templates
// ignore templates
// just select the text for rendering
export default class Document {
    public Text?: Array<string | { Text: string[] }> | string

    constructor(opts: DocumentConstructor) {        
        if (opts.Text) {
            this.Text = this.parseTextTag(opts.Text)
        }
    }

    public toString(): string {
        if (typeof this.Text === 'string') {
            return this.Text
        } else if (this.Text) {
            return this.Text.join('').replace(/^[ \t]+/gm, '')
        } else {
            return ''
        }
    }

    private parseTextTag(text: Text): string {
        // if text is an array
        if (Array.isArray(text)) {
            return text.map((t) => {
                if (typeof t === 'string') {
                    return t.replace(/^[ \t]+/gm, '').concat('\n')
                } else if (Array.isArray(t.Text)) {
                    return t.Text.join('').replace(/^[ \t]+/gm, '')
                } else {
                    return ''
                }
            }).join('')
        }

        // if text is a string
        if (typeof text === 'string') {
            return text
        }

        // if text is an object
        if (typeof text === 'object') {
            const inner = text.Text as string|string[]|Text
            if (Array.isArray(inner)) {
                return inner.join('').replace(/^[ \t]+/gm, '')
            } else if (typeof inner === 'string') {
                return inner
            } else {
                return this.parseTextTag(inner)
            }
        }
    }

}