package server

import (
	"fmt"
	"io"
	"regexp"
	"strings"

	"go.neonxp.ru/qchat/internal/chat"
)

var replacements = []replacement{
	{
		From: *regexp.MustCompile(`\*(.+?)\*`),
		To:   fmt.Sprintf("%s$1%s", escapeCodes[Bold], escapeCodes[Reset]),
	},
	{
		From: *regexp.MustCompile(`\+(.+?)\+`),
		To:   fmt.Sprintf("%s$1%s", escapeCodes[Italic], escapeCodes[Reset]),
	},
	{
		From: *regexp.MustCompile(`\-(.+?)\-`),
		To:   fmt.Sprintf("%s$1%s", escapeCodes[Strike], escapeCodes[Reset]),
	},
	{
		From: *regexp.MustCompile(`_(.+?)_`),
		To:   fmt.Sprintf("%s$1%s", escapeCodes[Underline], escapeCodes[Reset]),
	},
}

func processUserEvent(message any, w io.Writer, user *chat.User) {
	switch message := message.(type) {
	case chat.Message:
		displayMessage(w, message, user)
	case chat.SelfMessage:
		displaySelfMessage(w, message)
	case chat.SystemMessage:
		displaySystemMessage(w, message)
	case chat.UserJoined:
		displayUserJoined(w, message)
	case chat.UserLeft:
		displayUserLeft(w, message)
	case chat.UserLogs:
		displayUserLogs(w, message)
	}
}

func displayMessage(w io.Writer, message chat.Message, user *chat.User) {
	msg := message.Message
	mentionFrom := "@" + user.Username
	mentionTo := string(escapeCodes[Yellow]) + string(escapeCodes[Underline]) + "@" + user.Username + string(escapeCodes[Reset])
	if strings.Contains(msg, mentionFrom) {
		msg = strings.ReplaceAll(msg, mentionFrom, mentionTo)
		msg = "\x07\a" + msg
	}

	for _, r := range replacements {
		msg = r.From.ReplaceAllString(msg, r.To)
	}

	//nolint:errcheck
	fmt.Fprintf(w, "%s%18s%s [%s]%s: %s\n",
		escapeCodes[Blue],
		message.User.NUsername(),
		escapeCodes[Green],
		message.Time.Format("15:04:05"),
		escapeCodes[Reset],
		msg,
	)
}

func displaySystemMessage(w io.Writer, message chat.SystemMessage) {
	//nolint:errcheck
	fmt.Fprintf(w, "%s* %s %s\n",
		escapeCodes[Green],
		message.Message,
		escapeCodes[Reset],
	)
}
func displaySelfMessage(w io.Writer, message chat.SelfMessage) {
	//nolint:errcheck
	fmt.Fprintf(w, "%s* %s %s%s\n",
		escapeCodes[Blue],
		message.User.NUsername(),
		message.Message,
		escapeCodes[Reset],
	)
}

func displayUserJoined(w io.Writer, presence chat.UserJoined) {
	//nolint:errcheck
	fmt.Fprintf(w, "%s* %s joined to %s chan%s\n",
		escapeCodes[Green],
		presence.User.NUsername(),
		presence.Chan.Name,
		escapeCodes[Reset],
	)
}

func displayUserLeft(w io.Writer, presence chat.UserLeft) {
	//nolint:errcheck
	fmt.Fprintf(w, "%s* %s left %s chan%s\n",
		escapeCodes[Red],
		presence.User.NUsername(),
		presence.Chan.Name,
		escapeCodes[Reset],
	)
}
func displayUserLogs(w io.Writer, message chat.UserLogs) {
	messages := make([]string, 0, len(message.Logs))
	for _, m := range message.Logs {
		switch m.Type {
		case chat.TypeNone:
			continue
		case chat.TypeJoined:
			messages = append(messages, fmt.Sprintf("* %18s [%s]: joined", m.Username, m.Time.Format("15:04:05")))
		case chat.TypeLeft:
			messages = append(messages, fmt.Sprintf("* %18s [%s]: left", m.Username, m.Time.Format("15:04:05")))
		case chat.TypeMessage:
			messages = append(messages, fmt.Sprintf("%18s [%s]: %s", m.Username, m.Time.Format("15:04:05"), m.Message))
		}
	}

	if len(messages) == 0 {
		return
	}

	//nolint:errcheck
	fmt.Fprintf(w, "%s* Last channel messages:\n%s%s\n",
		escapeCodes[Blue],
		strings.Join(messages, "\n"),
		escapeCodes[Reset],
	)
}

type replacement struct {
	From regexp.Regexp
	To   string
}