package main

import (
	"errors"
	"io/ioutil"
	"os"
	"reflect"
	"strconv"
	"strings"

	"github.com/yosuke-furukawa/json5/encoding/json5"
	"github.com/zyedidia/glob"
)

// The options that the user can set
var globalSettings map[string]interface{}

// InitGlobalSettings initializes the options map and sets all options to their default values
func InitGlobalSettings() {
	defaults := DefaultGlobalSettings()
	var parsed map[string]interface{}

	filename := configDir + "/settings.json"
	writeSettings := false
	if _, e := os.Stat(filename); e == nil {
		input, err := ioutil.ReadFile(filename)
		if !strings.HasPrefix(string(input), "null") {
			if err != nil {
				TermMessage("Error reading settings.json file: " + err.Error())
				return
			}

			err = json5.Unmarshal(input, &parsed)
			if err != nil {
				TermMessage("Error reading settings.json:", err.Error())
			}
		} else {
			writeSettings = true
		}
	}

	globalSettings = make(map[string]interface{})
	for k, v := range defaults {
		globalSettings[k] = v
	}
	for k, v := range parsed {
		if !strings.HasPrefix(reflect.TypeOf(v).String(), "map") {
			globalSettings[k] = v
		}
	}

	if _, err := os.Stat(filename); os.IsNotExist(err) || writeSettings {
		err := WriteSettings(filename)
		if err != nil {
			TermMessage("Error writing settings.json file: " + err.Error())
		}
	}
}

// InitLocalSettings scans the json in settings.json and sets the options locally based
// on whether the buffer matches the glob
func InitLocalSettings(buf *Buffer) {
	var parsed map[string]interface{}

	filename := configDir + "/settings.json"
	if _, e := os.Stat(filename); e == nil {
		input, err := ioutil.ReadFile(filename)
		if err != nil {
			TermMessage("Error reading settings.json file: " + err.Error())
			return
		}

		err = json5.Unmarshal(input, &parsed)
		if err != nil {
			TermMessage("Error reading settings.json:", err.Error())
		}
	}

	for k, v := range parsed {
		if strings.HasPrefix(reflect.TypeOf(v).String(), "map") {
			g, err := glob.Compile(k)
			if err != nil {
				TermMessage("Error with glob setting ", k, ": ", err)
				continue
			}

			if g.MatchString(buf.Path) {
				for k1, v1 := range v.(map[string]interface{}) {
					buf.Settings[k1] = v1
				}
			}
		}
	}
}

// WriteSettings writes the settings to the specified filename as JSON
func WriteSettings(filename string) error {
	var err error
	if _, e := os.Stat(configDir); e == nil {
		parsed := make(map[string]interface{})

		filename := configDir + "/settings.json"
		for k, v := range globalSettings {
			parsed[k] = v
		}
		if _, e := os.Stat(filename); e == nil {
			input, err := ioutil.ReadFile(filename)
			if string(input) != "null" {
				if err != nil {
					return err
				}

				err = json5.Unmarshal(input, &parsed)
				if err != nil {
					TermMessage("Error reading settings.json:", err.Error())
				}

				for k, v := range parsed {
					if !strings.HasPrefix(reflect.TypeOf(v).String(), "map") {
						if _, ok := globalSettings[k]; ok {
							parsed[k] = globalSettings[k]
						}
					}
				}
			}
		}

		txt, _ := json5.MarshalIndent(parsed, "", "    ")
		err = ioutil.WriteFile(filename, txt, 0644)
	}
	return err
}

// AddOption creates a new option. This is meant to be called by plugins to add options.
func AddOption(name string, value interface{}) {
	globalSettings[name] = value
	err := WriteSettings(configDir + "/settings.json")
	if err != nil {
		TermMessage("Error writing settings.json file: " + err.Error())
	}
}

// GetGlobalOption returns the global value of the given option
func GetGlobalOption(name string) interface{} {
	return globalSettings[name]
}

// GetLocalOption returns the local value of the given option
func GetLocalOption(name string, buf *Buffer) interface{} {
	return buf.Settings[name]
}

// GetOption returns the value of the given option
// If there is a local version of the option, it returns that
// otherwise it will return the global version
func GetOption(name string) interface{} {
	if GetLocalOption(name, CurView().Buf) != nil {
		return GetLocalOption(name, CurView().Buf)
	}
	return GetGlobalOption(name)
}

// DefaultGlobalSettings returns the default global settings for micro
// Note that colorscheme is a global only option
func DefaultGlobalSettings() map[string]interface{} {
	return map[string]interface{}{
		"autoindent":   true,
		"colorscheme":  "zenburn",
		"cursorline":   true,
		"ignorecase":   false,
		"indentchar":   " ",
		"infobar":      true,
		"ruler":        true,
		"savecursor":   false,
		"saveundo":     false,
		"scrollspeed":  float64(2),
		"scrollmargin": float64(3),
		"statusline":   true,
		"syntax":       true,
		"tabsize":      float64(4),
		"tabstospaces": false,
	}
}

// DefaultLocalSettings returns the default local settings
// Note that filetype is a local only option
func DefaultLocalSettings() map[string]interface{} {
	return map[string]interface{}{
		"autoindent":   true,
		"cursorline":   true,
		"filetype":     "Unknown",
		"ignorecase":   false,
		"indentchar":   " ",
		"ruler":        true,
		"savecursor":   false,
		"saveundo":     false,
		"scrollspeed":  float64(2),
		"scrollmargin": float64(3),
		"statusline":   true,
		"syntax":       true,
		"tabsize":      float64(4),
		"tabstospaces": false,
	}
}

// SetOption attempts to set the given option to the value
// By default it will set the option as global, but if the option
// is local only it will set the local version
// Use setlocal to force an option to be set locally
func SetOption(option, value string) error {
	if _, ok := globalSettings[option]; !ok {
		if _, ok := CurView().Buf.Settings[option]; !ok {
			return errors.New("Invalid option")
		}
		SetLocalOption(option, value, CurView())
		return nil
	}

	kind := reflect.TypeOf(globalSettings[option]).Kind()
	if kind == reflect.Bool {
		b, err := ParseBool(value)
		if err != nil {
			return errors.New("Invalid value")
		}
		globalSettings[option] = b
	} else if kind == reflect.String {
		globalSettings[option] = value
	} else if kind == reflect.Float64 {
		i, err := strconv.Atoi(value)
		if err != nil {
			return errors.New("Invalid value")
		}
		globalSettings[option] = float64(i)
	}

	if option == "colorscheme" {
		LoadSyntaxFiles()
		for _, tab := range tabs {
			for _, view := range tab.views {
				view.Buf.UpdateRules()
				if view.Buf.Settings["syntax"].(bool) {
					view.matches = Match(view)
				}
			}
		}
	}

	if option == "infobar" {
		for _, tab := range tabs {
			tab.Resize()
		}
	}

	if _, ok := CurView().Buf.Settings[option]; ok {
		for _, tab := range tabs {
			for _, view := range tab.views {
				SetLocalOption(option, value, view)
			}
		}
	}

	return nil
}

// SetLocalOption sets the local version of this option
func SetLocalOption(option, value string, view *View) error {
	buf := view.Buf
	if _, ok := buf.Settings[option]; !ok {
		return errors.New("Invalid option")
	}

	kind := reflect.TypeOf(buf.Settings[option]).Kind()
	if kind == reflect.Bool {
		b, err := ParseBool(value)
		if err != nil {
			return errors.New("Invalid value")
		}
		buf.Settings[option] = b
	} else if kind == reflect.String {
		buf.Settings[option] = value
	} else if kind == reflect.Float64 {
		i, err := strconv.Atoi(value)
		if err != nil {
			return errors.New("Invalid value")
		}
		buf.Settings[option] = float64(i)
	}

	if option == "statusline" {
		view.ToggleStatusLine()
		if buf.Settings["syntax"].(bool) {
			view.matches = Match(view)
		}
	}

	if option == "filetype" {
		LoadSyntaxFiles()
		buf.UpdateRules()
		if buf.Settings["syntax"].(bool) {
			view.matches = Match(view)
		}
	}

	return nil
}

// SetOptionAndSettings sets the given option and saves the option setting to the settings config file
func SetOptionAndSettings(option, value string) {
	filename := configDir + "/settings.json"

	err := SetOption(option, value)

	if err != nil {
		messenger.Error(err.Error())
		return
	}

	err = WriteSettings(filename)
	if err != nil {
		messenger.Error("Error writing to settings.json: " + err.Error())
		return
	}
}