// Copyright (c) 2026 Charles KWON OhJun (charleskwonohjun@gmail.com)
// All rights reserved.

// dbEdit() — Harbour-compatible implementation using TBrowse.
// Same pattern as Harbour's dbedit.prg:
//   oBrowse := TBrowseDB() → addColumn → loop { stabilize + inkey + navigate }
package hbrtl

import (
	"five/hbrt"
	"five/hbrdd"
	"fmt"
	"strings"
)

// Key constants
const (
	kUP    = 5
	kDOWN  = 24
	kLEFT  = 19
	kRIGHT = 4
	kPGUP  = 18
	kPGDN  = 3
	kHOME  = 1
	kEND   = 6
	kESC   = 27
)

// DbEdit implements Harbour dbEdit() function.
func DbEdit(t *hbrt.Thread) {
	nParams := t.ParamCount()
	t.Frame(nParams, 0)
	defer t.EndProc()

	nTop := 0
	nLeft := 0
	nBottom := 22
	nRight := 79

	if nParams >= 1 {
		nTop = int(t.Local(1).AsNumInt())
	}
	if nParams >= 2 {
		nLeft = int(t.Local(2).AsNumInt())
	}
	if nParams >= 3 {
		nBottom = int(t.Local(3).AsNumInt())
	}
	if nParams >= 4 {
		nRight = int(t.Local(4).AsNumInt())
	}

	wa := getDbEditWA(t)
	if wa == nil {
		t.PushBool(false)
		t.RetValue()
		return
	}
	area := wa.Current()
	if area == nil {
		t.PushBool(false)
		t.RetValue()
		return
	}

	// Create TBrowse object
	oBrowse := hbrt.NewObject(hbrt.FindClass("TBROWSE").ID)
	arr := oBrowse.AsArray()
	cls := hbrt.GetClass(arr.Class)

	setF(arr, cls, "NTOP", hbrt.MakeInt(nTop))
	setF(arr, cls, "NLEFT", hbrt.MakeInt(nLeft))
	setF(arr, cls, "NBOTTOM", hbrt.MakeInt(nBottom))
	setF(arr, cls, "NRIGHT", hbrt.MakeInt(nRight))
	rowCount := nBottom - nTop - 1
	if rowCount < 1 {
		rowCount = 1
	}
	setF(arr, cls, "NROWCOUNT", hbrt.MakeInt(rowCount))
	setF(arr, cls, "CHEADSEP", hbrt.MakeString("-"))
	setF(arr, cls, "CCOLSEP", hbrt.MakeString(" | "))

	// Skip/GoTop/GoBottom blocks
	setF(arr, cls, "BSKIPBLOCK", hbrt.MakeBlock(func(bt *hbrt.Thread) {
		bt.Frame(1, 0)
		defer bt.EndProc()
		n := int(bt.Local(1).AsNumInt())
		bt.RetInt(int64(dbSkipBlock(wa, n)))
	}, 0))
	setF(arr, cls, "BGOTOPBLOCK", hbrt.MakeBlock(func(bt *hbrt.Thread) {
		bt.Frame(0, 0)
		defer bt.EndProc()
		if a := wa.Current(); a != nil {
			a.GoTop()
		}
		bt.RetNil()
	}, 0))
	setF(arr, cls, "BGOBOTTOMBLOCK", hbrt.MakeBlock(func(bt *hbrt.Thread) {
		bt.Frame(0, 0)
		defer bt.EndProc()
		if a := wa.Current(); a != nil {
			a.GoBottom()
		}
		bt.RetNil()
	}, 0))

	// Add columns
	colsArr := getFA(arr, cls, "ACOLUMNS")
	for i := 0; i < area.FieldCount(); i++ {
		fi := area.GetFieldInfo(i)
		idx := i

		oCol := hbrt.NewObject(hbrt.FindClass("TBCOLUMN").ID)
		ca := oCol.AsArray()
		cc := hbrt.GetClass(ca.Class)
		setF(ca, cc, "CHEADING", hbrt.MakeString(fi.Name))
		setF(ca, cc, "BBLOCK", hbrt.MakeBlock(func(bt *hbrt.Thread) {
			bt.Frame(0, 0)
			defer bt.EndProc()
			val, _ := area.GetValue(idx)
			bt.PushValue(val)
			bt.RetValue()
		}, 0))
		w := fi.Len
		if w < len(fi.Name) {
			w = len(fi.Name)
		}
		if w > 25 {
			w = 25
		}
		if w < 4 {
			w = 4
		}
		setF(ca, cc, "NWIDTH", hbrt.MakeInt(w))
		colsArr.Items = append(colsArr.Items, oCol)
	}

	// Set raw terminal mode
	dbEditRawOn()
	defer dbEditRawOff()
	fmt.Print("\033[2J\033[H\033[?25l")
	defer fmt.Print("\033[?25h\033[0m\n")

	area.GoTop()
	screenWidth := nRight - nLeft + 1
	rc, _ := area.RecCount()

	// Main loop — same as Harbour dbEdit
	for {
		// stabilize
		t.PushValue(oBrowse)
		t.Send("STABILIZE", 0)
		t.Pop2()

		// Status bar
		colPos := getFI(arr, cls, "NCOLPOS")
		colName := ""
		if colPos >= 1 && colPos <= len(colsArr.Items) {
			ca2 := colsArr.Items[colPos-1].AsArray()
			cc2 := hbrt.GetClass(ca2.Class)
			colName = getFS(ca2, cc2, "CHEADING")
		}
		eof := ""
		if area.EOF() {
			eof = " EOF"
		}
		status := fmt.Sprintf(" Rec %d/%d [%s]%s  Arrows PgUp/Dn Home/End ESC=quit",
			area.RecNo(), rc, strings.TrimSpace(colName), eof)
		fmt.Printf("\033[%d;%dH\033[7m%-*s\033[0m", nBottom+2, nLeft+1, screenWidth, status)

		// Read key
		key := dbEditReadKey()

		switch key {
		case 'A': // ESC[A = Up
			t.PushValue(oBrowse)
			t.Send("UP", 0)
			t.Pop2()
		case 'B': // ESC[B = Down
			t.PushValue(oBrowse)
			t.Send("DOWN", 0)
			t.Pop2()
		case 'D': // ESC[D = Left
			t.PushValue(oBrowse)
			t.Send("LEFT", 0)
			t.Pop2()
		case 'C': // ESC[C = Right
			t.PushValue(oBrowse)
			t.Send("RIGHT", 0)
			t.Pop2()
		case '5': // PgUp
			t.PushValue(oBrowse)
			t.Send("PAGEUP", 0)
			t.Pop2()
		case '6': // PgDn
			t.PushValue(oBrowse)
			t.Send("PAGEDOWN", 0)
			t.Pop2()
		case 'H': // Home
			t.PushValue(oBrowse)
			t.Send("GOTOP", 0)
			t.Pop2()
		case 'F': // End
			t.PushValue(oBrowse)
			t.Send("GOBOTTOM", 0)
			t.Pop2()
		case kESC, 'q', 'Q':
			fmt.Print("\033[2J\033[H")
			t.PushBool(true)
			t.RetValue()
			return
		}
	}
}

func dbEditRawOn() {
	InitRawTerminal() // from rawtty.go
}

func dbEditRawOff() {
	RestoreTerminal() // from rawtty.go
}

func dbEditReadKey() int {
	return ReadKey() // from rawtty.go
}

// helpers
func setF(a *hbrt.HbArray, c *hbrt.ClassDef, n string, v hbrt.Value) {
	if i := c.FieldIndex(n); i >= 0 {
		a.Items[i] = v
	}
}
func getFA(a *hbrt.HbArray, c *hbrt.ClassDef, n string) *hbrt.HbArray {
	if i := c.FieldIndex(n); i >= 0 {
		return a.Items[i].AsArray()
	}
	return nil
}
func getFI(a *hbrt.HbArray, c *hbrt.ClassDef, n string) int {
	if i := c.FieldIndex(n); i >= 0 {
		return int(a.Items[i].AsNumInt())
	}
	return 0
}
func getFS(a *hbrt.HbArray, c *hbrt.ClassDef, n string) string {
	if i := c.FieldIndex(n); i >= 0 {
		return a.Items[i].AsString()
	}
	return ""
}

func getDbEditWA(t *hbrt.Thread) *hbrdd.WorkAreaManager {
	if t.WA == nil {
		return nil
	}
	wa, ok := t.WA.(*hbrdd.WorkAreaManager)
	if !ok {
		return nil
	}
	return wa
}