package tg

import (
	"fmt"
	"io"
	"net/http"
	tgbotapi "github.com/go-telegram-bot-api/telegram-bot-api/v5"
	//"path"
)


// Interface to interact with the user.
type Context struct {
	session *Session
	// The update that called the Context usage.
	update Update
	// Used as way to provide outer values redirection
	// into widgets and actions. It is like arguments
	// for REST API request etc.
	arg any
	typ ContextType
	// Instead of updates as argument.
	input *UpdateChan
}

// Run commands as other user. Was implemented to
// make other user to leave the bot at first but
// maybe you will find another usage for this.
// Returns users context by specified session ID
// or nil if the user is not logged in.
func (c Context) As(sid SessionId) Context {
	n, ok := c.Bot.contexts[sid]
	if !ok {
		return nil
	}
	return &Context{
		context: n,
	}
}

// General type function to define actions, single component widgets
// and components themselves.
type Func func(Context)
func (f Func) Act(c Context) {
	f(c)
}
func (f Func) Serve(c Context) {
	f(c)
}
func(f Func) Filter(_ *Update) bool {
	return false
}
func (f Func) Render(_ *Context) UI {
	return UI{
		f,
	}
}

type ContextType uint8
const (
	NoContextType ContextType = iota
	WidgetContextType
	ActionContextType
)

// Goroutie function to handle each user.
func (c Context) serve() {
	beh := c.Bot.behaviour
	c.Run(beh.Init)
	beh.Root.Serve(c)
}

func (c Context) Path() Path {
	ln := len(c.pathHistory)
	if ln == 0 {
		return ""
	}
	return c.pathHistory[ln-1]
}

func (c Context) Arg() any {
	return c.arg
}

func (c Context) Run(a Action) {
	if a != nil {
		a.Act(c)
	}
}

// Only for the root widget usage.
// Skip the update sending it down to
// the underlying widget.
func (c Context) Skip(u Update) {
	c.skippedUpdates.Send(u)
}

// Sends to the Sendable object.
func (c Context) Send(v Sendable) (Message, error) {
	config := v.SendConfig(c.Session.Id, c.Bot)
	if config.Error != nil {
		return nil, config.Error
	}

	msg, err := c.Bot.Api.Send(config.ToApi())
	if err != nil {
		return nil, err
	}
	return &msg, nil
}

// Sends the formatted with fmt.Sprintf message to the user
// using default Markdown parsing format.
func (c Context) Sendf(format string, v ...any) (Message, error) {
	return c.Send(NewMessage(format, v...))
}

// Same as Sendf but uses Markdown 2 format for parsing.
func (c Context) Sendf2(format string, v ...any) (Message, error) {
	return c.Send(NewMessage(fmt.Sprintf(format, v...)).MD2())
}

// Same as Sendf but uses HTML format for parsing.
func (c Context) SendfHTML(format string, v ...any) (Message, error) {
	return c.Send(NewMessage(fmt.Sprintf(format, v...)).HTML())
}

// Send the message in raw format escaping all the special characters.
func (c Context) SendfR(format string, v ...any) (Message, error) {
	return c.Send(NewMessage(Escape2(fmt.Sprintf(format, v...))).MD2())
}

// Get the input for current widget.
// Should be used inside handlers (aka "Serve").
func (c Context) Input() chan Update {
	return c.input.Chan()
}

func (c Context) WithArg(v any) Context {
	c.arg = v
	return c
}

func (c Context) WithUpdate(u *Update) Context {
	c.Update = u
	return c
}

func (c Context) WithInput(input *UpdateChan) Context {
	c.input = input
	return c
}

func (c Context) Go(pth Path) error {
	return c.session.go_(pth, nil)
}

func (c Context) GoWithArg(pth Path, arg any) error {
	return c.session.go_(pth, arg)
}

// Customized actions for the bot.
type Action interface {
	Act(Context)
}

type ActionFunc func(Context)

func (af ActionFunc) Act(c *Context) {
	af(c)
}

func (c Context) History() []Path {
	return c.session.pathHistory
}

func (c Context) PathExist(pth Path) bool {
	return c.bot.behaviour.PathExist(pth)
}

// Simple way to read strings for widgets with
// the specified prompt.
func (c Context) ReadString(promptf string, args ...any) string {
	var text string
	if pref != "" {
		c.Sendf(promptf, args...)
	}
	for u := range c.Input() {
		if u == nil {
			break
		}
		if u.Message == nil {
			continue
		}
		text = u.Message.Text
		break
	}
	return text
}

func (c Context) Update() Update {
	return c.update
}

// Returns the reader for specified file ID and path.
func (c *Context) GetFile(fileId FileId) (io.ReadCloser, string, error) {
	file, err := c.Bot.Api.GetFile(tgbotapi.FileConfig{FileID:string(fileId)})
	if err != nil {
		return nil, "", err
	}
	r, err := http.Get(fmt.Sprintf(
		"https://api.telegram.org/file/bot%s/%s",
		c.Bot.Api.Token,
		file.FilePath,
	))
	if err != nil {
		return nil, "", err
	}
	if r.StatusCode != 200 {
		return nil, "", StatusCodeErr
	}

	return r.Body, file.FilePath, nil
}

func (c *Context) ReadFile(fileId FileId) ([]byte, string, error)  {
	file, pth, err := c.GetFile(fileId)
	if err != nil {
		return nil, "", err
	}
	defer file.Close()

	bts, err := io.ReadAll(file)
	if err != nil {
		return nil, "", err
	}

	return bts, pth, nil
}