package session

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"os"
	"strings"

	"git.andreafazzi.eu/andrea/probo/pkg/models"
	"git.andreafazzi.eu/andrea/probo/pkg/store/file"
	"github.com/alecthomas/chroma/quick"

	"github.com/charmbracelet/bubbles/key"
	"github.com/charmbracelet/bubbles/spinner"
	btTable "github.com/charmbracelet/bubbles/table"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/glamour"
	"github.com/charmbracelet/huh"
	"github.com/charmbracelet/lipgloss"
	"github.com/d5/tengo/v2"
	"github.com/d5/tengo/v2/stdlib"
	foam "github.com/remogatto/sugarfoam"
	"github.com/remogatto/sugarfoam/components/form"
	"github.com/remogatto/sugarfoam/components/group"
	"github.com/remogatto/sugarfoam/components/header"
	"github.com/remogatto/sugarfoam/components/help"
	"github.com/remogatto/sugarfoam/components/statusbar"
	"github.com/remogatto/sugarfoam/components/table"
	"github.com/remogatto/sugarfoam/components/viewport"
	"github.com/remogatto/sugarfoam/layout"
	"github.com/remogatto/sugarfoam/layout/tiled"
)

type SessionModel struct {
	// UI
	form      *form.Model
	viewport  *viewport.Model
	table     *table.Model
	group     *group.Model
	help      *help.Model
	statusBar *statusbar.Model
	spinner   spinner.Model

	// Layout
	document *layout.Layout

	// Key bindings
	bindings *keyBindings

	// store
	store    *file.SessionFileStore
	lenStore int
	result   []any

	// json
	InputJson string

	// session
	session *models.Session

	// markdown
	mdRenderer *glamour.TermRenderer

	// filter file
	scriptFilePath string

	state int
}

func New(path string, stdin string) *SessionModel {
	form := form.New(
		form.WithGroups(huh.NewGroup(
			huh.NewInput().
				Key("sessionTitle").
				Title("Session title").
				Description("Enter the title of the session").
				Validate(func(str string) error {
					if str == "" {
						return errors.New("You must set a session name!")
					}
					return nil

				}),
		)))

	formBinding := huh.NewDefaultKeyMap()
	formBinding.Input.Next = key.NewBinding(key.WithKeys("down"), key.WithHelp("down", "next"))
	formBinding.Input.Prev = key.NewBinding(key.WithKeys("up"), key.WithHelp("up", "prev"))
	formBinding.Confirm.Next = key.NewBinding(key.WithKeys("down"), key.WithHelp("down", "next"))
	formBinding.Confirm.Prev = key.NewBinding(key.WithKeys("up"), key.WithHelp("up", "prev"))

	form.WithShowHelp(false).WithTheme(huh.ThemeDracula()).WithKeyMap(formBinding)

	viewport := viewport.New()

	table := table.New(table.WithRelWidths(20, 30, 30, 20))
	table.Model.SetColumns([]btTable.Column{
		{Title: "Token", Width: 20},
		{Title: "Lastname", Width: 20},
		{Title: "Firstname", Width: 20},
		{Title: "Class", Width: 20},
	})

	group := group.New(
		group.WithItems(form, table, viewport),
		group.WithLayout(
			layout.New(
				layout.WithStyles(&layout.Styles{Container: lipgloss.NewStyle().Padding(1, 1)}),
				layout.WithItem(form),
				layout.WithItem(tiled.New(table, viewport)),
			),
		),
	)

	bindings := newBindings(group)
	statusBar := statusbar.New(bindings)

	s := spinner.New(
		spinner.WithStyle(
			lipgloss.NewStyle().Foreground(lipgloss.Color("265"))),
	)
	s.Spinner = spinner.Dot

	header := header.New(
		header.WithContent(
			lipgloss.NewStyle().
				Bold(true).
				Border(lipgloss.NormalBorder(), false, false, true, false).
				Render("✨ Create session ✨"),
		),
	)

	help := help.New(
		bindings,
		help.WithStyles(&foam.Styles{NoBorder: lipgloss.NewStyle().Padding(1, 1)}))

	document := layout.New(
		layout.WithStyles(&layout.Styles{Container: lipgloss.NewStyle().Margin(1)}),
		layout.WithItem(header),
		layout.WithItem(group),
		layout.WithItem(help),
		layout.WithItem(statusBar),
	)

	renderer, err := glamour.NewTermRenderer(
		glamour.WithStandardStyle("dracula"),
		glamour.WithWordWrap(80),
	)
	if err != nil {
		panic(err)
	}

	return &SessionModel{
		form:           form,
		table:          table,
		viewport:       viewport,
		group:          group,
		statusBar:      statusBar,
		spinner:        s,
		document:       document,
		mdRenderer:     renderer,
		bindings:       bindings,
		help:           help,
		scriptFilePath: path,
		InputJson:      stdin,
	}

}

func (m *SessionModel) Init() tea.Cmd {
	var cmds []tea.Cmd

	cmds = append(cmds, m.group.Init(), m.loadStore(), m.spinner.Tick)

	m.group.Focus()

	return tea.Batch(cmds...)
}

func (m *SessionModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	var cmds []tea.Cmd

	switch msg := msg.(type) {

	case tea.WindowSizeMsg:
		m.handleWindowSize(msg)

	case tea.KeyMsg:
		switch {
		case key.Matches(msg, m.bindings.quit):
			cmds = append(cmds, tea.Quit)
		}

	case storeLoadedMsg:
		cmds = append(cmds, m.handleStoreLoaded(msg))

	case scriptExecutedMsg:
		m.handleScriptExecuted(msg)

	case errorMsg:
		m.handleError(msg)
		m.state = ErrorState
	}

	cmds = m.handleState(msg, cmds)

	return m, tea.Batch(cmds...)
}

func (m *SessionModel) View() string {
	return m.document.View()
}

func (m *SessionModel) executeScript(path string) tea.Cmd {
	return func() tea.Msg {
		if m.scriptFilePath == "" {
			return nil
		}

		sessionJson, err := json.Marshal(models.Session{Exams: map[string]*models.Exam{}})
		if err != nil {
			panic(err)
		}

		script, err := os.ReadFile(m.scriptFilePath)
		if err != nil {
			return errorMsg{err}
		}

		s := tengo.NewScript(script)

		s.SetImports(stdlib.GetModuleMap("fmt", "json"))
		_ = s.Add("input", m.InputJson)
		_ = s.Add("output", string(sessionJson))

		c, err := s.Compile()
		if err != nil {
			return errorMsg{err}
		}

		if err := c.Run(); err != nil {
			return errorMsg{err}
		}

		return scriptExecutedMsg{fmt.Sprintf("%s", c.Get("output"))}

	}
}

func (m *SessionModel) createSession() error {
	m.session.Title = m.form.GetString("sessionTitle")

	_, err := m.store.Create(m.session)
	if err != nil {
		return err
	}

	return nil
}

func (m *SessionModel) showErrorOnStatusBar(err error) {
	m.statusBar.SetContent(
		stateFormats[ErrorState][0],
		fmt.Sprintf(stateFormats[ErrorState][1], err),
		stateFormats[ErrorState][2],
	)
}

func (m *SessionModel) updateTableContent(session *models.Session) {
	rows := make([]btTable.Row, 0)

	for token, exam := range session.Exams {
		rows = append(rows, btTable.Row{
			token,
			exam.Participant.Lastname,
			exam.Participant.Firstname,
			exam.Participant.Attributes.Get("class"),
		})

	}

	m.table.SetRows(rows)
}

func (m *SessionModel) updateViewportContent(session *models.Session) {
	currentToken := m.table.SelectedRow()[0]
	currentExam := session.Exams[currentToken]

	if currentExam == nil {
		panic("Current token is not associate to any exam!")
	}

	md, err := currentExam.ToMarkdown()
	if err != nil {
		m.showErrorOnStatusBar(err)
	}

	result, err := m.mdRenderer.Render(md)
	if err != nil {
		m.showErrorOnStatusBar(err)
	}

	m.viewport.SetContent(sanitize(result))

}

func (m *SessionModel) createMDRenderer() *glamour.TermRenderer {
	renderer, err := glamour.NewTermRenderer(
		glamour.WithStandardStyle("dracula"),
		glamour.WithWordWrap(m.viewport.GetWidth()),
	)
	if err != nil {
		panic(err)
	}
	return renderer
}

func (m *SessionModel) handleWindowSize(msg tea.WindowSizeMsg) {
	m.group.SetSize(msg.Width, msg.Height)
	m.document.SetSize(msg.Width, msg.Height)
	m.mdRenderer = m.createMDRenderer()
}

func (m *SessionModel) handleError(msg tea.Msg) {
	err := msg.(errorMsg)

	m.statusBar.SetContent(
		stateFormats[ErrorState][0],
		fmt.Sprintf(stateFormats[ErrorState][1], err.error),
		stateFormats[ErrorState][2],
	)
}

func (m *SessionModel) handleScriptExecuted(msg tea.Msg) {
	session := new(models.Session)
	jsonData := []byte(msg.(scriptExecutedMsg).result)

	err := json.Unmarshal(jsonData, &session)
	if err != nil {
		panic(err)
	}

	m.session = session

	m.updateTableContent(session)
	m.updateViewportContent(session)

	m.state = BrowseState
}

func (m *SessionModel) handleStoreLoaded(msg tea.Msg) tea.Cmd {
	storeMsg := msg.(storeLoadedMsg)

	m.store = storeMsg.store
	m.lenStore = len(m.store.ReadAll())

	return m.executeScript(m.scriptFilePath)

}

func (m *SessionModel) handleState(msg tea.Msg, cmds []tea.Cmd) []tea.Cmd {
	_, cmd := m.group.Update(msg)

	if m.state == LoadingStoreState {
		return m.updateSpinner(msg, cmd, cmds)
	}

	if m.form.State == huh.StateCompleted {
		err := m.createSession()
		if err != nil {
			panic(err)
		}
		cmds = append(cmds, tea.Quit)
	}

	if len(m.form.Errors()) > 0 {
		m.state = ErrorState
		for _, err := range m.form.Errors() {
			m.showErrorOnStatusBar(err)
		}
	} else {
		m.state = BrowseState
	}

	if m.state == BrowseState {
		m.updateViewportContent(m.session)
	}

	if m.state != ErrorState {
		m.statusBar.SetContent(
			stateFormats[BrowseState][0],
			fmt.Sprintf(stateFormats[BrowseState][1], m.lenStore, len(m.session.Exams)),
			stateFormats[BrowseState][2],
		)
	}

	cmds = append(cmds, cmd)

	return cmds
}

func (m *SessionModel) updateSpinner(msg tea.Msg, cmd tea.Cmd, cmds []tea.Cmd) []tea.Cmd {
	m.spinner, cmd = m.spinner.Update(msg)

	m.statusBar.SetContent(fmt.Sprintf(stateFormats[m.state][0], m.spinner.View()), stateFormats[m.state][1], stateFormats[m.state][2])

	cmds = append(cmds, cmd)

	return cmds
}

func (m *SessionModel) loadStore() tea.Cmd {
	return func() tea.Msg {
		sStore, err := file.NewDefaultSessionFileStore()
		if err != nil {
			panic(err)
		}

		return storeLoadedMsg{sStore}
	}
}

func toColoredJson(data []any) (string, error) {
	result, err := json.MarshalIndent(data, "", " ")
	if err != nil {
		return "", err
	}

	coloredBytes := make([]byte, 0)
	buffer := bytes.NewBuffer(coloredBytes)

	err = quick.Highlight(buffer, string(result), "json", "terminal16m", "dracula")
	if err != nil {
		panic(err)
	}

	return sanitize(buffer.String()), nil
}

func sanitize(text string) string {
	// FIXME: The use of a standard '-' character causes rendering
	// issues within the viewport. Further investigation is
	// required to resolve this problem.
	return strings.Replace(text, "-", "–", -1)
}