package cmd

import (
	"bytes"
	"context"
	"io"
	"os"
	"os/exec"
	"strings"

	"code.icb4dc0.de/buildr/buildr/internal/tui"

	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/glamour"
	"github.com/muesli/termenv"
)

var (
	_ Pager = (*TUIPager)(nil)
	_ Pager = (*CommandPager)(nil)
)

func NewTUIPager(title string) (*TUIPager, error) {
	renderer, err := glamour.NewTermRenderer(
		glamour.WithStyles(glamour.DraculaStyleConfig),
		glamour.WithEmoji(),
		glamour.WithAutoStyle(),
	)
	if err != nil {
		return nil, err
	}

	return &TUIPager{
		title:    title,
		renderer: renderer,
	}, nil
}

type TUIPager struct {
	renderer *glamour.TermRenderer
	title    string
}

func (t *TUIPager) Write(p []byte) (n int, err error) {
	return t.renderer.Write(p)
}

func (t *TUIPager) Display() error {
	if err := t.renderer.Close(); err != nil {
		return err
	}

	builder := new(strings.Builder)
	_, _ = io.Copy(builder, t.renderer)

	tuiProgram := tea.NewProgram(
		tui.NewPager(t.title, builder.String()),
		tea.WithAltScreen(),
	)

	_, err := tuiProgram.Run()
	return err
}

func NewCmdPager(ctx context.Context, pagerCmd string, colorize bool) (p *CommandPager, err error) {
	var (
		renderer *glamour.TermRenderer
		buf      *bytes.Buffer
	)
	if colorize {
		renderer, err = glamour.NewTermRenderer(
			glamour.WithStyles(glamour.DraculaStyleConfig),
			glamour.WithColorProfile(termenv.TrueColor),
			glamour.WithEmoji(),
			glamour.WithAutoStyle(),
		)
		if err != nil {
			return nil, err
		}
	} else {
		buf = bytes.NewBuffer(nil)
	}

	split := strings.Split(pagerCmd, " ")
	var (
		executable = split[0]
		args       []string
	)

	if len(split) > 1 {
		args = split[1:]
	}

	return &CommandPager{
		cmd:      exec.CommandContext(ctx, executable, args...),
		renderer: renderer,
		buf:      buf,
	}, nil
}

type CommandPager struct {
	cmd      *exec.Cmd
	renderer *glamour.TermRenderer
	buf      *bytes.Buffer
}

func (c *CommandPager) Write(p []byte) (n int, err error) {
	if c.renderer != nil {
		return c.renderer.Write(p)
	}
	return c.buf.Write(p)
}

func (c *CommandPager) Display() error {
	if c.renderer != nil {
		if err := c.renderer.Close(); err != nil {
			return err
		}
		c.cmd.Stdin = c.renderer
	} else {
		c.cmd.Stdin = c.buf
	}

	c.cmd.Stdout = os.Stdout
	c.cmd.Stderr = os.Stderr

	return c.cmd.Run()
}