/*
Copyright © Brian Buller <brian@bullercodeworks.com>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
package widgets

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

	wd "git.bullercodeworks.com/brian/tcell-widgets"
	wh "git.bullercodeworks.com/brian/tcell-widgets/helpers"
	"github.com/gdamore/tcell"
)

type JsonContent struct {
	id string

	valueString string
	contents    []string
	style       tcell.Style
	x, y        int
	w, h        int

	border  []rune
	visible bool
	active  bool
	keyMap  *wd.KeyMap

	editable bool
	value    any
	jsonObj  map[string]json.RawMessage
	jsonArr  json.RawMessage
	isObj    bool

	activeNode []string

	vimMode bool
	cursor  int

	editKey, editVal bool
	editValType      int

	logger func(string, ...any)
}

const (
	JsonTpString = iota
	JsonTpBool
	JsonTpNumber
	JsonTpObject
	JsonTpArray
	JsonTpErr
)

var _ wd.Widget = (*JsonContent)(nil)

func NewJsonContent(id string, style tcell.Style) *JsonContent {
	ret := &JsonContent{}
	ret.Init(id, style)
	return ret
}

func (w *JsonContent) Init(id string, style tcell.Style) {
	w.id = id
	w.style = style
	w.visible = true
	w.keyMap = wd.NewKeyMap(
		wd.NewKey(wd.BuildEK(tcell.KeyUp), func(_ *tcell.EventKey) bool { return w.MoveUp() }),
		wd.NewKey(wd.BuildEK(tcell.KeyDown), func(_ *tcell.EventKey) bool { return w.MoveDown() }),
		wd.NewKey(wd.BuildEK(tcell.KeyEnter), func(ev *tcell.EventKey) bool { return false }),
		wd.NewKey(wd.BuildEK(tcell.KeyPgDn), func(_ *tcell.EventKey) bool { return w.PageDn() }),
		wd.NewKey(wd.BuildEK(tcell.KeyPgUp), func(_ *tcell.EventKey) bool { return w.PageUp() }),
		wd.NewKey(wd.BuildEKr('j'), func(ev *tcell.EventKey) bool {
			if !w.vimMode {
				return false
			}
			return w.MoveDown()
		}),
		wd.NewKey(wd.BuildEKr('k'), func(ev *tcell.EventKey) bool {
			if !w.vimMode {
				return false
			}
			return w.MoveUp()
		}),
		wd.NewKey(wd.BuildEKr('b'), func(ev *tcell.EventKey) bool {
			if !w.vimMode {
				return false
			}
			if ev.Modifiers()&tcell.ModCtrl != 0 {
				return w.PageUp()
			}
			return false
		}),
		wd.NewKey(wd.BuildEKr('f'), func(ev *tcell.EventKey) bool {
			if !w.vimMode {
				return false
			}
			if ev.Modifiers()&tcell.ModCtrl != 0 {
				return w.PageDn()
			}
			return false
		}),
	)
}

func (w *JsonContent) Id() string                         { return w.id }
func (w *JsonContent) HandleResize(ev *tcell.EventResize) { w.w, w.h = ev.Size() }

func (w *JsonContent) GetKeyMap() *wd.KeyMap   { return w.keyMap }
func (w *JsonContent) SetKeyMap(km *wd.KeyMap) { w.keyMap = km }

func (w *JsonContent) HandleKey(ev *tcell.EventKey) bool {
	return w.keyMap.Handle(ev)
}
func (w *JsonContent) HandleTime(ev *tcell.EventTime) {}
func (w *JsonContent) Draw(screen tcell.Screen) {
	if !w.visible {
		return
	}
	x, y := w.x, w.y
	brdSz := 0
	if len(w.border) > 0 {
		brdSz = 2
		wh.BorderFilled(x, y, x+w.w, y+w.h, w.border, w.style, screen)
	}
	x, y = x+1, y+1
	h := w.h - brdSz
	ln := len(w.contents)
	start, end := 0, ln-1
	if ln == 0 {
		return
	}
	if ln > w.h-2 {
		mid := h / 2
		if w.cursor < mid {
			// contents need to start at 0
			end = h + 1
		} else if w.cursor > ln-mid {
			// contents need to begin at ln-h
			start = ln - h + 1
		} else {
			start = w.cursor - mid
			end = start + h + 1
		}
	}
	// ed cannot be higher than ln-1
	if start < 0 {
		start = 0
	}
	if end > ln-1 {
		end = ln - 1
	}
	for i := start; i <= end; i++ {
		stl := w.style
		dim := i != w.cursor
		if dim {
			stl = stl.Foreground(tcell.ColorGreen)
		}
		txt := w.contents[i]
		if len(txt) > w.w-brdSz && w.w-brdSz >= 0 {
			txt = txt[:(w.w - brdSz)]
		}
		if w.editable && i == w.cursor {
			pth, err := w.GetSelectedPath()
			if err != nil {
				wh.DrawText(x, y, fmt.Sprintf("%s", err.Error()), stl, screen)
			} else {
				key, val, err := w.getItemKeyVal(w.cursor)
				if err != nil {
					wh.DrawText(x, y, fmt.Sprintf("%s: %s", pth, err.Error()), stl, screen)
				} else {
					wh.DrawText(x, y, fmt.Sprintf("%s: %s -> %s", pth, key, val), stl, screen)
				}
			}
		} else {
			wh.DrawText(x, y, txt, stl.Dim(dim).Bold(!dim), screen)
		}
		y++
	}
}

func (w *JsonContent) SetStyle(s tcell.Style) { w.style = s }
func (w *JsonContent) Active() bool           { return w.active }
func (w *JsonContent) SetActive(a bool) bool {
	w.active = a
	return w.active
}
func (w *JsonContent) Visible() bool      { return w.visible }
func (w *JsonContent) SetVisible(a bool)  { w.visible = a }
func (w *JsonContent) SetX(x int)         { w.x = x }
func (w *JsonContent) SetY(y int)         { w.y = y }
func (w *JsonContent) GetX() int          { return w.x }
func (w *JsonContent) GetY() int          { return w.y }
func (w *JsonContent) GetPos() wd.Coord   { return wd.Coord{X: w.x, Y: w.y} }
func (w *JsonContent) SetPos(c wd.Coord)  { w.x, w.y = c.X, c.Y }
func (w *JsonContent) SetW(x int)         { w.w = x }
func (w *JsonContent) SetH(y int)         { w.h = y }
func (w *JsonContent) GetW() int          { return w.w }
func (w *JsonContent) GetH() int          { return w.h }
func (w *JsonContent) WantW() int         { return wh.Longest(w.contents) }
func (w *JsonContent) WantH() int         { return len(w.contents) }
func (w *JsonContent) SetSize(c wd.Coord) { w.w, w.h = c.X, c.Y }
func (w *JsonContent) MinW() int          { return wh.Longest(w.contents) }
func (w *JsonContent) MinH() int          { return len(w.contents) }

func (w *JsonContent) SetValue(v any) error {
	w.value = v
	// Go ahead and try to build the json for v
	bts, err := json.MarshalIndent(v, "", "  ")
	if err != nil {
		return fmt.Errorf("error unmarshalling value: %w", err)
	}
	w.valueString = string(bts)
	w.contents = strings.Split(w.valueString, "\n")
	if bts[0] == '{' {
		err = json.Unmarshal(bts, &w.jsonObj)
		w.isObj = true
	} else if bts[0] == '[' {
		err = json.Unmarshal(bts, &w.jsonArr)
		w.isObj = false
	} else {
		// Item is just a flat string/number/boolean
		w.cursor = 0
	}
	if !w.isLineSelectable(w.cursor) {
		idx := w.findPrevSelectableLine(w.cursor)
		if idx == -1 {
			idx = w.findNextSelectableLine(w.cursor)
		}
		if idx >= 0 {
			w.cursor = idx
		}
	}
	return err
}

func (w *JsonContent) SetBorder(brd []rune) {
	if len(brd) == 0 {
		w.border = wh.BRD_SIMPLE
	} else {
		w.border = wh.ValidateBorder(brd)
	}
}

func (w *JsonContent) SetEditable(v bool) { w.editable = v }

func (w *JsonContent) SetVimMode(b bool) { w.vimMode = b }
func (w *JsonContent) MoveUp() bool {
	idx := w.findPrevSelectableLine(w.cursor)
	if idx < 0 {
		return false
	}
	w.cursor = idx
	return true
}
func (w *JsonContent) MoveDown() bool {
	idx := w.findNextSelectableLine(w.cursor)
	if idx < 0 {
		return false
	}
	w.cursor = idx
	return true
}
func (w *JsonContent) PageUp() bool {
	idx := w.findPrevSelectableLine(w.cursor - w.h)
	if idx < 0 {
		return false
	}
	w.cursor = idx
	return true
}
func (w *JsonContent) PageDn() bool {
	idx := w.findNextSelectableLine(w.cursor + w.h)
	if idx < 0 {
		return false
	}
	w.cursor = idx
	return true
}

func (w *JsonContent) GetSelectedPath() ([]string, error) { return w.getItemPath(w.cursor) }
func (w *JsonContent) GetSelectedKey() (string, error)    { return w.getItemKey(w.cursor) }
func (w *JsonContent) GetSelectedValue() (string, error)  { return w.getItemVal(w.cursor) }
func (w *JsonContent) getSelectedItemDepth() int          { return w.getItemDepth(w.cursor) }

func (w *JsonContent) getItemPath(line int) ([]string, error) {
	if line < 0 || line >= len(w.contents) {
		return []string{}, errors.New("invalid line number")
	}
	depth := w.getItemDepth(line)
	if depth == 1 {
		key, err := w.getItemKey(line)
		if err != nil {
			return []string{}, err
		}
		return []string{key}, nil
	}
	pth, err := w.getItemPath(w.findItemParentLine(line))
	if err != nil {
		return []string{}, err
	}
	key, err := w.getItemKey(line)
	if err != nil {
		return []string{}, err
	}
	return append(pth, key), nil
}

func (w *JsonContent) getItemKeyVal(line int) (string, string, error) {
	if line < 0 || line >= len(w.contents) {
		return "", "", errors.New("invalid line number")
	}
	text := w.contents[line]
	key, rest := w.getNextQuotedString(text)
	if key == "" {
		return "", "", errors.New("error finding quoted string")
	} else if rest == "" {
		// We have a 'key' value, but no 'rest' so this is likely an item in array
		return "", key, nil
	}
	rest = strings.Trim(rest, ":{[}], ")
	val, rest := w.getNextQuotedString(rest)
	if val != "" {
		return key, val, nil
	}
	return key, rest, nil
}

func (w *JsonContent) getItemKey(line int) (string, error) {
	if line < 0 || line >= len(w.contents) {
		return "", errors.New("invalid line number")
	}

	key, _ := w.getNextQuotedString(w.contents[line])
	if key == "" {
		return "", errors.New("error finding quoted string")
	}
	return key, nil
}

func (w *JsonContent) getItemVal(line int) (string, error) {
	if line < 0 || line >= len(w.contents) {
		return "", errors.New("invalid line number")
	}
	var key, val, rest string
	key, rest = w.getNextQuotedString(w.contents[line])
	if len(rest) > 0 {
		val, rest = w.getNextQuotedString(rest)
	}
	if len(val) > 0 {
		return val, nil
	}
	if len(key) > 0 {
		return key, nil
	}
	return "", errors.New("error finding value")
}

/*
func (w *JsonContent) getItemValType(line int) int {
	if line < 0 || line >= len(w.contents) {
		return JsonTypeErr
	}

	text := w.contents[line]
	key, rest := w.getNextQuotedString(text)
	rest = strings.Trim(rest, ", ")
	if rest == "" {
		if key != "" {
			// Looks like a string value in an array
			return JsonTypeString
		} else rest == "true" || rest == "false" {
			return JsonTypeBool
		}
		// see if we can parse this as a number
		num, err := strconv.Atoi(rest)
		if err == nil {
			return JsonTypeNumber
		}
		return JsonType
	}
	if key == "" {
		return "", "", errors.New("error finding quoted string")
	} else if rest == "" {
		// We have a 'key' value, but no 'rest' so this is likely an item in array
		return "", key, nil
	}
	rest = strings.Trim(rest, ":, ")
	if rest[0] == '{' {

	}
	val, rest := w.getNextQuotedString(rest)
	if val != "" {
		return key, val, nil
	}
	// Val isn't a quoted string,
	return key, rest, nil
}
*/

func (w *JsonContent) getItemDepth(line int) int {
	if line < 0 || line >= len(w.contents) {
		return 0
	}
	txt := w.contents[line]
	// Find the depth, we use two spaces to indent
	for i := range txt {
		if txt[i] != ' ' {
			return i / 2
		}
	}
	return 0
}

func (w *JsonContent) findItemParentLine(line int) int {
	depth := w.getItemDepth(line)
	if depth <= 1 {
		return -1
	}
	for i := w.cursor; i >= 0; i-- {
		if w.getItemDepth(i) < depth {
			return i
		}
	}
	return -1
}

func (w *JsonContent) getItemParentKey(line int) (string, error) {
	return w.getItemKey(w.findItemParentLine(line))
}
func (w *JsonContent) getItemParentVal(line int) (string, error) {
	return w.getItemVal(w.findItemParentLine(line))
}
func (w *JsonContent) getNextQuotedString(line string) (string, string) {
	var inQ, slash bool
	var ret string
	for i := range line {
		if inQ {
			if line[i] == '"' && !slash {
				return ret, line[i+1:]
			} else if slash {
				slash = false
			} else if line[i] == '\\' {
				slash = true
			}
			ret = fmt.Sprintf("%s%c", ret, line[i])
		}
		if line[i] == '"' {
			inQ = true
		}
	}
	// if we're here, we didn't find a quoted string
	return "", line
}

func (w *JsonContent) isLineSelectable(line int) bool {
	if line < 0 || line >= len(w.contents) {
		return false
	}
	return strings.Contains(w.contents[line], "\"")
}

func (w *JsonContent) findPrevSelectableLine(from int) int {
	for i := from - 1; i >= 0; i-- {
		if w.isLineSelectable(i) {
			return i
		}
	}
	return -1
}

func (w *JsonContent) findNextSelectableLine(from int) int {
	for i := from + 1; i < len(w.contents); i++ {
		if w.isLineSelectable(i) {
			return i
		}
	}
	return -1
}

func (w *JsonContent) SetLogger(l func(string, ...any)) { w.logger = l }
func (w *JsonContent) Log(txt string, args ...any)      { w.logger(txt, args...) }