SFM-loan-Rest-Api/pay-in-decode.go

package main

import (
	"biukop.com/sfm/loan"
	"errors"
	log "github.com/sirupsen/logrus"
	"os/exec"
	"strings"
)

type FunderType string

const (
	Funder_AAA     FunderType = "AAA Financial"
	Funder_Pepper             = "Pepper"
	Funder_Resimac            = "Resimac"
	Funder_Unknown            = "cannot detect funder type"
)

type AiDecodeIncome struct {
	Id     int64
	Input  loan.Uploads
	ul     uploadsOnDisk // internal data
	Mime   string        //mime actually detected.
	PayIn  []loan.PayIn
	Funder FunderType
	AAA    []PayInAAAPeriod
}

func (m *AiDecodeIncome) decodeUploadToPayIn(ulMeta loan.Uploads) (e error) {
	m.Id = ulMeta.Id
	m.Input = ulMeta
	m.ul.Upload = ulMeta

	m.PayIn = make([]loan.PayIn, 0, 10)
	switch m.getFileType() {
	case "pdf":
		m.decodePdf()
		break
	case "excel", "opensheet":
		m.decodeXls()
		break
	default:
		e = errors.New("unknown format")
		m.Funder = "" // mark unknown decoding
	}

	return
}

func (m *AiDecodeIncome) getFileType() (ret string) {
	strMime, e := GetFileContentType(m.ul.filePath())
	if e != nil {
		return
	}
	m.Mime = strMime

	ret, e = m.ul.GetFileType()
	if e != nil {
		ret = ""
	}
	return
}

func (m *AiDecodeIncome) decodePdf() (e error) {
	cmd := exec.Command("pdftotext", "-layout", m.ul.filePath(), "-")
	out, e := cmd.Output()
	if e != nil {
		log.Fatal(e)
	}

	raw := string(out)
	switch m.detectFunder(raw) {
	case Funder_AAA:
		m.Funder = Funder_AAA
		e = m.decodeAAAPdf(raw)
		log.Println("AAA final result", m.AAA)
		break
	case Funder_Unknown:
		e = errors.New(Funder_Unknown)
		break // not able to detect Funder
	}
	return
}

func (m *AiDecodeIncome) decodeXls() (e error) {
	return
}

func (m *AiDecodeIncome) detectFunder(raw string) FunderType {
	if m.isAAA(raw) {
		return Funder_AAA
	}

	return Funder_Unknown
}

func (m *AiDecodeIncome) isAAA(raw string) bool {
	keyword := "AAA Financial Trail Report"
	lines := strings.Split(raw, "\n")
	return m.checkFunderKeyword(keyword, lines, 0, 3)
}

func (m *AiDecodeIncome) checkFunderKeyword(keyword string, lines []string, start int, end int) bool {
	for idx, line := range lines {
		// first 10 lines has Key word
		if strings.Contains(line, keyword) && idx >= start && idx <= 10 {
			return true
		}
	}
	return false
}