package cardsim

import (
	"fmt"
	"os"
	"strconv"
	"strings"
)

func RunSimpleTerminalUI[C StatsCollection](p *Player[C]) error {

	err := p.StartNextTurn()
	if p.DebugLevel < 1 && IsSeriousError(err) {
		return err
	}
	p.ReportError(err)

	for {
		for p.CanAct() {
			isCard, cardIdx, choiceIdx, err := pickNextAction(p)
			p.ReportError(err)
			if IsSeriousError(err) {
				if p.DebugLevel < 1 {
					return err
				}
				continue
			}
			var msg Message
			if isCard {
				msg, err = p.EnactCard(cardIdx, choiceIdx)
			} else {
				msg, err = p.EnactPermanentAction(cardIdx, choiceIdx)
			}
			p.ReportError(err)
			if IsSeriousError(err) {
				if p.DebugLevel < 1 {
					return err
				}
				continue
			}
			display(msg)
			wait()
		}

		// Allow player to review state before continuing simulation.
		// Errors from review mode are reported *after* the simulation
		// step because the first thing Simulate does is throw out old
		// messages -- like these errors.
		reviewErr := review(p)
		if p.DebugLevel < 1 && IsSeriousError(err) {
			return reviewErr
		}
		err = p.Simulate()
		if p.DebugLevel < 1 && IsSeriousError(err) {
			return err
		}
		// Simulation errors are already in messages; now add the review error.
		p.ReportError(reviewErr)

		if p.DebugLevel < 1 && p.State.Over() {
			return nil
		}
	}
	// loop forever until the game ends or the player quits
}

func display(m Message) {
	if m == nil {
		return
	}
	fmt.Println(m.String())
}

func wait() {
	fmt.Println()
	fmt.Println("<press ENTER to continue>")
	fmt.Scanln()
}

func displayMainMenu[C StatsCollection](p *Player[C]) (actionsOffset, handOffset, max int) {
	cls()
	needsDivider := displayMessageSection(p)
	if needsDivider {
		divider()
	}
	displayOnePanel(p, p.Prompt)
	divider()
	actionsOffset = displayStatsMenu(p)
	if actionsOffset > 0 {
		divider()
	}
	handOffset = displayPermanentActionsMenu(p, actionsOffset)
	if handOffset > actionsOffset {
		fmt.Println()
	}
	max = displayHandMenu(p, handOffset)
	return // uses named return values
}

func pickNextAction[C StatsCollection](p *Player[C]) (isCard bool, cardIdx int, choiceIdx int, err error) {
	for {
		actionsOffset, handOffset, max := displayMainMenu(p)

		divider()
		fmt.Printf("%d actions remaining.\n", p.ActionsRemaining)
		fmt.Printf("Show just (M)essages, (I)nfo Panels, (A)ctions, or consider an item (1-%d), or (Q)uit? > ", max)
		input := getResponse()
		switch input {
		// Special cases
		case "m", "msg", "message", "messages":
			cls()
			if displayMessageSection(p) {
				divider()
			}
			displayOnePanel(p, p.Prompt)
			wait()
		case "s", "stat", "stats", "i", "info", "p", "panel", "panels", "infopanel", "infopanels":
			statsMode(p)
		case "a", "act", "actions":
			var committed bool
			isCard, cardIdx, choiceIdx, committed, err = actionsMode(p, true)
			if committed {
				return
			}
		case "q", "quit", "exit":
			confirmQuit()
		default:
			i, err := strconv.Atoi(input)
			if err != nil {
				fmt.Println("Sorry, I don't understand.")
				wait()
			} else if i > max {
				fmt.Println("That's not on this menu. If the menu is too big to read, choose a detail view.")
				wait()
			} else if i <= actionsOffset {
				cls()
				displayOnePanel(p, p.InfoPanels[i-1])
				wait()
			} else if i <= handOffset {
				i = i - actionsOffset - 1
				option, promptErr := promptCard(p, p.PermanentActions[i])
				if option >= 0 || IsSeriousError(promptErr) {
					return false, i, option, promptErr
				}
			} else {
				i = i - handOffset - 1
				option, promptErr := promptCard(p, p.Hand[i])
				if option >= 0 || IsSeriousError(promptErr) {
					return true, i, option, nil
				}
			}
		}
	}
}

func cls() {
	fmt.Println("\033[H\033[2J")
}

func getResponse() string {
	var input string
	fmt.Scanln(&input)
	input = strings.TrimSpace(input)
	input = strings.ToLower(input)
	return input
}

func divider() {
	fmt.Println()
	fmt.Println(ChapterBreak.String())
	fmt.Println()
}

func lightDivider() {
	fmt.Println()
	fmt.Println(SectionBreak.String())
	fmt.Println()
}

func confirmQuit() {
	divider()
	fmt.Println("Are you sure you want to quit? (Y/N) > ")
	s := getResponse()
	if s == "y" || s == "yes" {
		fmt.Println("Bye!")
		os.Exit(0)
	}
}

func displayOnePanel[C StatsCollection](p *Player[C], panel InfoPanel[C]) error {
	ts := panel.Title(p).String()
	if len(ts) > 0 {
		fmt.Println(ts)
		fmt.Println(strings.Repeat("-", len(ts)))
		fmt.Println()
	}
	m, err := panel.Info(p)
	if IsSeriousError(err) {
		return err
	}
	display(MultiMessage(m))
	return err
}

func displayMessageSection[C StatsCollection](p *Player[C]) bool {
	if len(p.TemporaryMessages) == 0 {
		return false
	}
	hasPrevious := false
	for _, m := range p.TemporaryMessages {
		if m != nil {
			if hasPrevious {
				lightDivider()
			}
			display(m)
			hasPrevious = true
		}
	}
	return true
}

func displayStatsMenu[C StatsCollection](p *Player[C]) int {
	if len(p.InfoPanels) == 0 {
		return 0
	}
	fmt.Println("Info Panels")
	fmt.Println("-----------")
	for i, s := range p.InfoPanels {
		fmt.Printf("[%2d]: %s\n", i+1, s.Title(p).String())
	}
	return len(p.InfoPanels)
}

func displayPermanentActionsMenu[C StatsCollection](p *Player[C], offset int) int {
	if len(p.PermanentActions) == 0 {
		return offset
	}
	fmt.Println("Always Available")
	fmt.Println("----------------")
	for i, s := range p.PermanentActions {
		fmt.Printf("[%2d]: %s\n", i+offset+1, s.Title(p))
	}
	return offset + len(p.PermanentActions)
}

func displayHandMenu[C StatsCollection](p *Player[C], offset int) int {
	if len(p.Hand) == 0 {
		return offset
	}
	fmt.Println("Hand")
	fmt.Println("----")
	for i, s := range p.Hand {
		fmt.Printf("[%2d]: %s\n", i+offset+1, s.Title(p))
	}
	return offset + len(p.Hand)
}

// promptCard asks the player to take an action on a card. Returns the option
// they chose, or -1 if there was a serious error or they cancelled selection.
func promptCard[C StatsCollection](p *Player[C], card Card[C]) (optionIdx int, err error) {
	// Iterate until the player makes a valid choice.
	for {
		opts, valid, err := displayCard(p, card, true)
		if IsSeriousError(err) {
			return -1, err
		}
		fmt.Println()
		if valid {
			fmt.Printf("Go (B)ack, (Q)uit, or enact a choice (1 - %d)? > ", len(opts))
		} else {
			fmt.Print("Go (B)ack or (Q)uit? > ")
		}
		read := getResponse()
		switch read {
		case "b", "back":
			return -1, err
		case "q", "quit":
			confirmQuit()
		default:
			i, convErr := strconv.Atoi(read)
			if convErr != nil {
				fmt.Println("Sorry, I don't understand.")
				wait()
			} else if !valid {
				fmt.Println("You can't enact anything here.")
				wait()
			} else if i <= 0 || i > len(opts) {
				fmt.Println("That's not one of the options.")
				wait()
			} else if !opts[i-1].Enabled(p) {
				fmt.Println("That option is not available to you right now.")
				wait()
			} else {
				return i - 1, err
			}
		}
		// Invalid selection made -- loop to prompt again.
	}
}

func displayCard[C StatsCollection](p *Player[C], card Card[C], canAct bool) ([]CardOption[C], bool, error) {
	cls()
	t := card.Title(p).String()
	urgent := card.Urgent(p)
	if urgent {
		t = "[URGENT!] " + t
	}
	fmt.Println(t)
	fmt.Println(strings.Repeat("-", len(t)))
	fmt.Println()
	event, err := card.EventText(p)
	if IsSeriousError(err) {
		return nil, false, err
	}
	var errs ErrorCollector
	errs.Add(err)
	fmt.Println(event.String())
	fmt.Println()
	fmt.Println(SectionBreak.String())
	fmt.Println()
	if !urgent && p.HasUrgentCards() {
		fmt.Println("<You have more urgent matters to attend to! You cannot act on this right now.>")
		fmt.Println()
		canAct = false
	}
	opts, optErr := card.Options(p)
	errs.Add(optErr)
	if IsSeriousError(optErr) {
		return nil, false, errs.Emit()
	}
	valid := false
	for i, opt := range opts {
		pfx := "[xx]:"
		if opt.Enabled(p) {
			if canAct {
				pfx = fmt.Sprintf("[%2d]:", i+1)
				valid = true
			} else {
				pfx = "[--]:"
			}
		}
		t, err := opt.OptionText(p)
		errs.Add(err)
		if IsSeriousError(err) {
			return nil, false, errs.Emit()
		}
		fmt.Println(pfx, t.String())
	}
	return opts, valid, errs.Emit()
}

func statsMode[C StatsCollection](p *Player[C]) error {
	var errs ErrorCollector
	for {
		cls()
		n := displayStatsMenu(p)
		if n <= 0 {
			fmt.Println("No info panels are available.")
			wait()
			return errs.Emit()
		}
		fmt.Println()
		fmt.Printf("Go (B)ack, (Q)uit, or view an info panel (1-%d)? > ", n)
		s := getResponse()
		switch s {
		case "b", "back":
			return errs.Emit()
		case "q", "quit":
			confirmQuit()
		default:
			v, err := strconv.Atoi(s)
			if err != nil {
				fmt.Println("Sorry, I don't understand.")
				wait()
			} else if v <= 0 || v > n {
				fmt.Println("There's no info panel with that index.")
			} else {
				err := displayOnePanel(p, p.InfoPanels[v-1])
				errs.Add(err)
				if IsSeriousError(err) {
					return errs.Emit()
				}
				wait()
			}
		}
		// Loop to re-display info panels menu.
	}
}

func actionsMode[C StatsCollection](p *Player[C], canAct bool) (isCard bool, cardIdx, choiceIdx int, committed bool, err error) {
	var errs ErrorCollector
	for {
		cls()
		pOff := displayPermanentActionsMenu(p, 0)
		if pOff > 0 {
			fmt.Println()
		}
		max := displayHandMenu(p, pOff)

		if max <= 0 {
			fmt.Println("There are no actions available and no cards in hand.")
			fmt.Println("That's a problem. The game is stuck.")
			confirmQuit()
			errs.Add(WarningStalemate)
			return false, -1, -1, true, errs.Emit()
		}

		fmt.Println()
		if canAct {
			fmt.Printf("Go (B)ack, (Q)uit, or consider an action (1-%d)? > ", max)
		} else {
			fmt.Printf("Go (B)ack, (Q)uit, or view an action (1-%d)? > ", max)
		}
		input := getResponse()
		switch input {
		case "b", "back":
			return false, -1, -1, false, errs.Emit()
		case "q", "quit":
			confirmQuit()
		default:
			v, err := strconv.Atoi(input)
			if err != nil {
				fmt.Println("Sorry, I don't understand.")
				wait()
			} else if v < 1 || v > max {
				fmt.Println("That's not a card or action.")
				wait()
			} else if v <= pOff {
				v--
				if canAct {
					optIdx, err := promptCard(p, p.PermanentActions[v])
					errs.Add(err)
					if optIdx >= 0 || IsSeriousError(err) {
						return false, v, optIdx, true, errs.Emit()
					}
				} else {
					_, _, err := displayCard(p, p.PermanentActions[v], false)
					errs.Add(err)
					if IsSeriousError(err) {
						return false, -1, -1, true, errs.Emit()
					}
					wait()
				}
			} else {
				v = v - pOff - 1
				if canAct {
					optIdx, err := promptCard(p, p.Hand[v])
					errs.Add(err)
					if optIdx >= 0 || IsSeriousError(err) {
						return true, v, optIdx, false, errs.Emit()
					}
				} else {
					_, _, err := displayCard(p, p.Hand[v], false)
					errs.Add(err)
					if IsSeriousError(err) {
						return false, -1, -1, false, errs.Emit()
					}
					wait()
				}
			}
		}
		// Re-prompt to get a valid choice.
	}
}

func review[C StatsCollection](p *Player[C]) error {
	var errs ErrorCollector
	for {
		actionsOffset, handOffset, max := displayMainMenu(p)
		divider()
		fmt.Println("No actions remaining.")
		fmt.Printf("(C)ontinue, review just (M)essages, (I)nfo Panels, (A)ctions, or an item (1-%d), or (Q)uit? > ", max)
		input := getResponse()
		switch input {
		// Special cases
		case "m", "msg", "message", "messages":
			cls()
			if displayMessageSection(p) {
				divider()
			}
			displayOnePanel(p, p.Prompt)
			wait()
		case "s", "stat", "stats", "i", "info", "p", "panel", "panels", "infopanel", "infopanels":
			err := statsMode(p)
			errs.Add(err)
			if IsSeriousError(err) {
				return errs.Emit()
			}
		case "a", "act", "actions":
			_, _, _, _, err := actionsMode(p, false)
			errs.Add(err)
			if IsSeriousError(err) {
				return errs.Emit()
			}
		case "q", "quit", "exit":
			confirmQuit()
		case "c", "continue", "ok":
			return errs.Emit()
		default:
			i, err := strconv.Atoi(input)
			if err != nil {
				fmt.Println("Sorry, I don't understand.")
				wait()
			} else if i <= 0 || i > max {
				fmt.Println("That's not on this menu. If the menu is too big to read, choose a detail view.")
				wait()
			} else if i <= actionsOffset {
				cls()
				displayOnePanel(p, p.InfoPanels[i-1])
				wait()
			} else if i <= handOffset {
				i = i - actionsOffset - 1
				_, _, err := displayCard(p, p.PermanentActions[i], false)
				errs.Add(err)
				if IsSeriousError(err) {
					return errs.Emit()
				}
				wait()
			} else {
				i = i - handOffset - 1
				_, _, err := displayCard(p, p.Hand[i], false)
				errs.Add(err)
				if IsSeriousError(err) {
					return errs.Emit()
				}
				wait()
			}
		}
	}
}