package main

import (
	"bytes"
	"errors"
	"fmt"
	"io/ioutil"
	"local/oauth2"
	"net/http"
	"net/url"
	"os"
	"path"
	"regexp"
	"strconv"
	"strings"
	"time"

	yaml "gopkg.in/yaml.v2"
)

func Upload(config Config, transaction *Transaction) error {
	switch config.Uploader {
	case UploaderTodo:
		return uploadTodo(config, transaction)
	case UploaderLedger:
		return uploadLedger(config, transaction)
	case UploaderPTTodo:
		return uploadPTTodo(config, transaction)
	default:
		return errors.New("not impl: uploader")
	}
}

func uploadTodo(config Config, transaction *Transaction) error {
	params := url.Values{
		"list":  {config.TodoList},
		"title": {transaction.Format()},
		"tag":   {config.TodoTag},
	}
	req, err := http.NewRequest("POST", config.TodoAddr+"/ajax.php?newTask", strings.NewReader(params.Encode()))
	if err != nil {
		return err
	}
	req.Header.Set("Cookie", oauth2.COOKIE+"="+config.TodoToken)
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		b, _ := ioutil.ReadAll(resp.Body)
		return fmt.Errorf("bad status from todo: %v: %s", resp.StatusCode, b)
	}
	return nil
}

func uploadPTTodo(config Config, transaction *Transaction) error {
	b, err := ioutil.ReadFile(config.TodoAddr)
	if os.IsNotExist(err) {
		b = []byte("todo:\n")
	} else if err != nil {
		return err
	} else if len(b) == 0 {
		b = []byte("todo:\n")
	}
	f, err := ioutil.TempFile(os.TempDir(), path.Base(config.TodoAddr))
	if err != nil {
		return err
	}
	defer f.Close()
	sep := []byte{'\n'}
	seek := []byte("todo:")
	for len(b) > 0 {
		idx := bytes.Index(b, sep)
		if idx == -1 {
			idx = len(b) - 1
		}
		fmt.Fprintf(f, "%s\n", b[:idx])
		if bytes.Equal(bytes.TrimSpace(b[:idx]), seek) {
			fmt.Fprintf(f, `- {"todo":%q, "tags":%q}%s`, transaction.Format(), config.TodoTag, "\n")
		}
		b = b[idx+1:]
	}
	f.Close()
	var v interface{}
	if b, err := ioutil.ReadFile(f.Name()); err != nil {
		return err
	} else if err := yaml.Unmarshal(b, &v); err != nil {
		return err
	}
	return os.Rename(f.Name(), config.TodoAddr)
}

func uploadLedger(config Config, transaction *Transaction) error {
	f, err := os.OpenFile(config.TodoAddr, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		return err
	}
	defer f.Close()
	amount, _ := strconv.ParseFloat(transaction.Amount, 32)
	amount *= -1
	remote := "Withdrawal:"
	if amount > 0 {
		remote = "Deposit:"
	}
	regexp := regexp.MustCompile(`[0-9a-zA-Z]`)
	for _, substr := range regexp.FindAllString(transaction.Vendor, -1) {
		remote += substr
	}
	fmt.Fprintf(f, "%-50s%-s\n", formatGMailDate(transaction.Date), transaction.Vendor)
	fmt.Fprintf(f, "%-50s%-50s$%.2f\n", "", "AssetAccount:"+transaction.Bank.String()+":"+transaction.Account, amount)
	fmt.Fprintf(f, "%-50s%-s\n", "", remote)
	return nil
}

func formatGMailDate(s string) string {
	for _, format := range []string{
		"[Mon, 2 Jan 2006 15:04:05 -0700 (MST)]",
		"[Mon, 2 Jan 2006 15:04:05 -0700]",
	} {
		time, err := time.Parse(format, s)
		if err == nil {
			return time.Format("2006-01-02")
		}
	}
	return s
}