package main

import (
	"encoding/json"
	"errors"
	"fmt"
	"math/rand"
	"os"
	"os/user"
	"path"
	"strings"
	"time"

	tuser "git.tilde.town/tildetown/town/user"
	"github.com/gdamore/tcell/v2"
	"github.com/rivo/tview"
)

const (
	signupDir   = "/town/signups"
	acceptedDir = "/town/signups/accepted"
	rejectedDir = "/town/signups/rejected"
)

func getTitle() string {
	titles := []string{
		"yo bum rush the show",
		"can i kick it?",
		"super nintendo sega genesis",
		"birthdays was the worst days",
		"where were you when we were getting high?",
		"it's real time, real time, time to get real",
	}
	return titles[rand.Intn(len(titles))]
}

type townSignup struct {
	When         time.Time
	DecisionTime time.Time
	Decision     string
	Filename     string
	Answers      map[string]string
}

func (s townSignup) Accept() error {
	return s.review("accept")
}

func (s townSignup) Reject() error {
	return s.review("reject")
}

func (s townSignup) review(decision string) error {
	s.DecisionTime = time.Now()
	s.Decision = "decision"
	oldpath := path.Join(signupDir, s.Filename)
	newpath := path.Join(acceptedDir, s.Filename)
	if decision == "reject" {
		newpath = path.Join(rejectedDir, s.Filename)
	}
	return os.Rename(oldpath, newpath)
}

func (s townSignup) Render() string {
	out := fmt.Sprintf("[-:-:b]submitted:[-:-:-] %s\n", s.When.Format("2006-01-02 15:04"))

	for k, v := range s.Answers {
		out += fmt.Sprintf("[-:-:b]%s[-:-:-]\n", k)
		out += strings.TrimSpace(v)
		out += "\n\n"
	}

	return out
}

func getSignups() ([]townSignup, error) {
	entries, err := os.ReadDir(signupDir)
	if err != nil {
		return nil, fmt.Errorf("failed to read '%s': %w", signupDir, err)
	}
	out := []townSignup{}
	for _, entry := range entries {
		if !strings.HasSuffix(entry.Name(), "json") {
			continue
		}

		abs := path.Join(signupDir, entry.Name())
		data, err := os.ReadFile(abs)
		if err != nil {
			return nil, fmt.Errorf("could not read signup file '%s': %w", abs, err)
		}

		fmt.Println(string(data))

		var signup townSignup
		err = json.Unmarshal(data, &signup)
		if err != nil {
			return nil, fmt.Errorf("could not unmarshal signup file '%s': %w", abs, err)
		}
		signup.Filename = entry.Name()

		out = append(out, signup)
	}

	return out, nil
}

func _main() error {
	u, err := user.Current()
	if err != nil {
		return fmt.Errorf("that's my purse. I don't know you! %w", err)
	}
	isAdmin, err := tuser.IsAdmin(u)
	if err != nil {
		return fmt.Errorf("that's my purse. I don't know you! %w", err)
	}

	if !isAdmin {
		return errors.New("this command can only be run by a town admin")
	}
	rand.Seed(time.Now().Unix())

	signups, err := getSignups()
	if err != nil {
		return fmt.Errorf("could not get signups: %w", err)
	}

	signupIx := 0

	title := tview.NewTextView()
	title.SetText(getTitle())
	title.SetTextAlign(tview.AlignCenter)
	title.SetTextColor(tcell.ColorPurple)
	title.SetBackgroundColor(tcell.ColorBlack)

	appView := tview.NewTextView()
	appView.SetDynamicColors(true)
	if len(signups) == 0 {
		appView.SetText("no signups found.")
	} else {
		appView.SetText(signups[signupIx].Render())
	}

	legend := tview.NewTextView()
	legend.SetText("s: skip r: random A: approve R: reject N: notate Q: quit")
	legend.SetTextColor(tcell.ColorPurple)
	legend.SetTextAlign(tview.AlignCenter)
	legend.SetBackgroundColor(tcell.ColorBlack)

	count := tview.NewTextView()
	count.SetDynamicColors(true)
	updateCount := func() {
		count.SetText(fmt.Sprintf("[-:-:b]%d pending signups[-:-:-]", len(signups)))
	}
	updateCount()

	bottomFlex := tview.NewFlex()
	bottomFlex.SetDirection(tview.FlexColumn)
	bottomFlex.AddItem(count, 0, 1, false)
	bottomFlex.AddItem(legend, 0, 10, false)

	mainFlex := tview.NewFlex()
	mainFlex.SetDirection(tview.FlexRow)
	mainFlex.AddItem(title, 1, -1, false)
	mainFlex.AddItem(appView, 0, 1, true)
	mainFlex.AddItem(bottomFlex, 1, -1, false)

	pages := tview.NewPages()

	errorModal := tview.NewModal()
	errorModal.AddButtons([]string{"damn"})
	errorModal.SetDoneFunc(func(ix int, _ string) {
		pages.SwitchToPage("main")
	})

	pages.AddPage("main", mainFlex, true, true)
	pages.AddPage("error", errorModal, false, false)
	// TODO page for textarea to notate

	app := tview.NewApplication()
	app.SetRoot(pages, true)

	// TODO count of pending signups somewhere

	// TODO replace imperative shit with signupManager
	advanceSignup := func() {
		if len(signups) == 0 {
			appView.SetText("no signups found.")
			return
		}
		signupIx++
		if signupIx == len(signups) {
			signupIx = 0
		}
		appView.SetText(signups[signupIx].Render())
	}

	removeSignup := func(signup townSignup) {
		newSignups := []townSignup{}
		for ix, s := range signups {
			if ix != signupIx {
				newSignups = append(newSignups, s)
			}
		}
		signups = newSignups
		if len(signups) > 0 {
			if signupIx >= len(signups) {
				signupIx = 0
			}
		}
		appView.SetText(signups[signupIx].Render())
	}

	app.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
		switch event.Rune() {
		case 's':
			advanceSignup()
		case 'r':
			if len(signups) > 0 {
				signupIx = rand.Intn(len(signups))
				appView.SetText(signups[signupIx].Render())
			}
		case 'A':
			if len(signups) == 0 {
				return nil
			}
			signup := signups[signupIx]
			err := signup.Accept()
			if err != nil {
				errorModal.SetText(fmt.Sprintf("error! failed to approve '%s': %s", signup.Filename, err.Error()))
				pages.SwitchToPage("error")
			} else {
				removeSignup(signup)
				updateCount()
			}
		case 'R':
			if len(signups) == 0 {
				return nil
			}
			signup := signups[signupIx]
			err = signup.Reject()
			if err != nil {
				errorModal.SetText(fmt.Sprintf("error! failed to reject '%s': %s", signup.Filename, err.Error()))
				pages.SwitchToPage("error")
			} else {
				removeSignup(signup)
				updateCount()
			}
		case 'N':
			if len(signups) == 0 {
				return nil
			}
			// TODO notate
		case 'Q':
			app.Stop()
		}

		return event
	})

	return app.Run()
}

func main() {
	err := _main()
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
}