package command

import (
	"fmt"
	"strconv"
	"strings"

	"git.gophernest.net/azpect/TextEditor/internal/action"
	tea "github.com/charmbracelet/bubbletea"
)

// QuitMsg: Message signaling the application should quit.
type QuitMsg struct{}

// ErrorMsg: Message signaling an error to display.
type ErrorMsg struct {
	Err error
}

// cmdQuit: Handles :quit / :q command.
func cmdQuit(m action.Model, args []string) tea.Cmd {
	return func() tea.Msg {
		return tea.Quit()
	}
}

// cmdQuitAll: Handles :qall / :qa command.
func cmdQuitAll(m action.Model, args []string) tea.Cmd {
	return func() tea.Msg {
		return tea.Quit()
	}
}

// cmdWrite: Handles :write / :w command (TODO: implement file saving).
func cmdWrite(m action.Model, args []string) tea.Cmd {
	// TODO: Implement file saving
	// If args provided, save to that filename
	// Otherwise save to current file
	return nil
}

// cmdWriteAll: Handles :wall / :wa command (TODO: implement saving all buffers).
func cmdWriteAll(m action.Model, args []string) tea.Cmd {
	// TODO: Implement saving all buffers
	return nil
}

// cmdWriteQuit: Handles :wq command (TODO: save then quit).
func cmdWriteQuit(m action.Model, args []string) tea.Cmd {
	// TODO: Save then quit
	return func() tea.Msg {
		return tea.Quit()
	}
}

// cmdRegisters: Handles :register command (debug - displays register content).
func cmdRegisters(m action.Model, args []string) tea.Cmd {
	// TODO: This is temporary, for debugging
	if len(args) < 1 {
		m.SetCommandError(fmt.Errorf("Please provide a name. Register dump not yet implemented."))
		return nil
	}

	if len(args[0]) != 1 {
		m.SetCommandError(fmt.Errorf("Name should be a single character."))
		return nil
	}

	name := rune(args[0][0])
	reg, found := m.GetRegister(name)
	if !found {
		m.SetCommandError(fmt.Errorf("Could not find register '%c'.", name))
		return nil
	}

	content := strings.Join(reg.Content, "\\n")
	t := reg.Type
	m.SetCommandOutput(fmt.Sprintf("Type: %d Name: \"%c Content: %s", t, name, content))
	return nil
}

// cmdSet: Handles :set option[=value] command for configuring editor settings.
// Examples:
//
//	:set number        - enable number
//	:set nonumber      - disable number
//	:set number!       - toggle number
//	:set tabstop=4     - set tabstop to 4
//	:set ts=4          - set tabstop to 4 (abbreviation)
func cmdSet(m action.Model, args []string) tea.Cmd {
	if len(args) == 0 {
		out := fmt.Sprintf("%+v", m.Settings())
		m.SetCommandOutput(out)
		return nil
	}

	for _, arg := range args {
		if err := parseSetOption(m, arg); err != nil {
			m.SetCommandError(err)
			return nil
		}
	}

	return nil
}

// Setting: Represents a configurable editor option.
type Setting struct {
	Name      string
	ShortForm string
	Type      SettingType
	Get       func(m action.Model) any
	Set       func(m action.Model, val any)
}

// SettingType: Enumeration of setting value types.
type SettingType int

const (
	BoolSetting SettingType = iota
	IntSetting
	StringSetting
)

// settingsMap defines all available settings (both global and window-local)
var settingsMap = []Setting{
	// Global editor settings
	{
		Name:      "tabstop",
		ShortForm: "ts",
		Type:      IntSetting,
		Get:       func(m action.Model) any { return m.Settings().TabStop },
		Set: func(m action.Model, val any) {
			s := m.Settings()
			s.TabStop = val.(int)
			m.SetSettings(s)
		},
	},
	// Window-local settings
	{
		Name:      "number",
		ShortForm: "nu",
		Type:      BoolSetting,
		Get:       func(m action.Model) any { return m.ActiveWindow().Options.Number },
		Set: func(m action.Model, val any) {
			w := m.ActiveWindow()
			o := w.Options
			o.Number = val.(bool)
			w.SetOptions(o)
		},
	},
	{
		Name:      "relativenumber",
		ShortForm: "rnu",
		Type:      BoolSetting,
		Get:       func(m action.Model) any { return m.ActiveWindow().Options.RelativeNumber },
		Set: func(m action.Model, val any) {
			w := m.ActiveWindow()
			o := w.Options
			o.RelativeNumber = val.(bool)
			w.SetOptions(o)
		},
	},
	{
		Name:      "scrolloff",
		ShortForm: "so",
		Type:      IntSetting,
		Get:       func(m action.Model) any { return m.ActiveWindow().Options.ScrollOff },
		Set: func(m action.Model, val any) {
			w := m.ActiveWindow()
			o := w.Options
			o.ScrollOff = val.(int)
			w.SetOptions(o)
		},
	},
	{
		Name:      "guttersize",
		ShortForm: "gu",
		Type:      IntSetting,
		Get:       func(m action.Model) any { return m.ActiveWindow().Options.GutterSize },
		Set: func(m action.Model, val any) {
			w := m.ActiveWindow()
			o := w.Options
			o.GutterSize = val.(int)
			w.SetOptions(o)
		},
	},
}

// lookupSetting: Finds a setting by name, short form, or prefix.
func lookupSetting(name string) *Setting {
	for i := range settingsMap {
		s := &settingsMap[i]
		if name == s.Name || name == s.ShortForm {
			return s
		}
		// Prefix matching
		if len(name) >= len(s.ShortForm) && strings.HasPrefix(s.Name, name) {
			return s
		}
	}
	return nil
}

// parseSetOption: Parses and applies a single :set option.
func parseSetOption(m action.Model, opt string) error {
	// Handle toggle: option!
	if name, ok := strings.CutSuffix(opt, "!"); ok {
		setting := lookupSetting(name)
		if setting != nil && setting.Type == BoolSetting {
			currentVal := setting.Get(m).(bool)
			setting.Set(m, !currentVal)
		}
		return nil
	}

	// Handle disable: nooption
	if name, ok := strings.CutPrefix(opt, "no"); ok {
		setting := lookupSetting(name)
		if setting != nil && setting.Type == BoolSetting {
			setting.Set(m, false)
		}
		return nil
	}

	// Handle assignment: option=value
	if strings.Contains(opt, "=") {
		parts := strings.SplitN(opt, "=", 2)
		name, value := parts[0], parts[1]

		setting := lookupSetting(name)
		if setting != nil {
			switch setting.Type {
			case IntSetting:
				intVal, err := strconv.Atoi(value)
				if err != nil {
					return err
				}
				setting.Set(m, intVal)
			case StringSetting:
				setting.Set(m, value)
			case BoolSetting:
				// Handle :set option=true / :set option=false
				boolVal := value == "true" || value == "1" || value == "yes"
				setting.Set(m, boolVal)
			}
		}
		return nil
	}

	// Handle enable: option (boolean only)
	setting := lookupSetting(opt)
	if setting != nil && setting.Type == BoolSetting {
		setting.Set(m, true)
	}

	return nil
}