package main

import (
	"fmt"
	"strings"
)

// === ПОИСК В СТРОКЕ (f/t команды) ===

func (m *EditorModel) findCharInLine(char rune, forward bool) {
	line := []rune(m.lines[m.cursorY])

	if forward {
		for i := m.cursorX + 1; i < len(line); i++ {
			if line[i] == char {
				m.cursorX = i
				m.lastFindChar = char
				m.lastFindIsForward = true
				return
			}
		}
	} else {
		for i := m.cursorX - 1; i >= 0; i-- {
			if line[i] == char {
				m.cursorX = i
				m.lastFindChar = char
				m.lastFindIsForward = false
				return
			}
		}
	}
	m.SetStatusMsg("Character not found")
}

func (m *EditorModel) findCharToLine(char rune, forward bool) {
	line := []rune(m.lines[m.cursorY])

	if forward {
		for i := m.cursorX + 1; i < len(line); i++ {
			if line[i] == char {
				if i > 0 {
					m.cursorX = i - 1
				}
				m.lastFindChar = char
				m.lastFindIsForward = true
				return
			}
		}
	} else {
		for i := m.cursorX - 1; i >= 0; i-- {
			if line[i] == char {
				if i < len(line)-1 {
					m.cursorX = i + 1
				}
				m.lastFindChar = char
				m.lastFindIsForward = false
				return
			}
		}
	}
	m.SetStatusMsg("Character not found")
}

func (m *EditorModel) repeatLastFind(reverse bool) {
	if m.lastFindChar == 0 {
		m.SetStatusMsg("No previous search")
		return
	}
	forward := m.lastFindIsForward
	if reverse {
		forward = !forward
	}
	m.findCharInLine(m.lastFindChar, forward)
}

// === ГЛОБАЛЬНЫЙ ПОИСК (/pattern) ===

func (m *EditorModel) startSearch() {
	m.mode = SEARCH
	m.searchBuffer = ""
	m.searchMatches = nil
	m.searchIdx = 0
	m.SetStatusMsg("/")
}

// maxSearchMatches — максимум совпадений при поиске
// Предотвращает зависание на файлах с сотнями тысяч строк
const maxSearchMatches = 1000

func (m *EditorModel) performSearch(pattern string) {
	m.lastSearchTerm = pattern
	m.searchMatches = nil
	m.searchIdx = 0

	if pattern == "" {
		return
	}

	patRunes := []rune(pattern)
	truncated := false

	for lineNum, line := range m.lines {
		lineRunes := []rune(line)
		for i := 0; i <= len(lineRunes)-len(patRunes); i++ {
			match := true
			for j, r := range patRunes {
				if lineRunes[i+j] != r {
					match = false
					break
				}
			}
			if match {
				m.searchMatches = append(m.searchMatches, struct{ line, col int }{lineNum, i})
				if len(m.searchMatches) >= maxSearchMatches {
					truncated = true
					break
				}
			}
		}
		if truncated {
			break
		}
	}

	if len(m.searchMatches) > 0 {
		match := m.searchMatches[0]
		m.cursorY = match.line
		m.cursorX = match.col
		m.searchIdx = 0
		if truncated {
			m.SetStatusMsg(fmt.Sprintf("Found %d+ matches (showing first %d): %s",
				maxSearchMatches, maxSearchMatches, pattern))
		} else {
			m.SetStatusMsg(fmt.Sprintf("Found %d match(es): %s", len(m.searchMatches), pattern))
		}
	} else {
		m.SetStatusMsg("Pattern not found: " + pattern)
	}
}

func (m *EditorModel) nextMatch() {
	if len(m.searchMatches) == 0 {
		return
	}
	m.searchIdx = (m.searchIdx + 1) % len(m.searchMatches)
	match := m.searchMatches[m.searchIdx]
	m.cursorY = match.line
	m.cursorX = match.col
}

func (m *EditorModel) prevMatch() {
	if len(m.searchMatches) == 0 {
		return
	}
	m.searchIdx--
	if m.searchIdx < 0 {
		m.searchIdx = len(m.searchMatches) - 1
	}
	match := m.searchMatches[m.searchIdx]
	m.cursorY = match.line
	m.cursorX = match.col
}

// === ЗАМЕНА ===

func (m *EditorModel) replaceAll(old, new string) int {
	if old == "" {
		return 0
	}
	count := 0
	for i, line := range m.lines {
		newLine := strings.ReplaceAll(line, old, new)
		if newLine != line {
			count += strings.Count(line, old)
			m.lines[i] = newLine
			m.MarkDirty()
		}
	}
	return count
}

func (m *EditorModel) replaceInLine(old, new string) int {
	if old == "" || m.cursorY >= len(m.lines) {
		return 0
	}
	line := m.lines[m.cursorY]
	newLine := strings.Replace(line, old, new, 1)
	if newLine != line {
		m.lines[m.cursorY] = newLine
		m.MarkDirty()
		return 1
	}
	return 0
}

// === ЧИСЛОВЫЕ ПРЕФИКСЫ ===

func (m *EditorModel) parseNumberPrefix() int {
	if m.numPrefix == "" {
		return 1
	}
	result := 0
	for _, ch := range m.numPrefix {
		result = result*10 + int(ch-'0')
	}
	m.numPrefix = ""
	return result
}

// === НАВИГАЦИЯ ===

func (m *EditorModel) moveByWords(count int, forward bool) {
	for i := 0; i < count; i++ {
		if forward {
			m.moveNextWord()
		} else {
			m.movePrevWord()
		}
	}
}

func (m *EditorModel) moveByLines(count int, direction int) {
	m.cursorY += count * direction
	m.CursorWithinBounds()
}

// findMatchingBracket — поиск парной скобки (%)
func (m *EditorModel) findMatchingBracket() {
	if m.cursorY >= len(m.lines) {
		return
	}
	line := []rune(m.lines[m.cursorY])
	if m.cursorX >= len(line) {
		return
	}

	char := line[m.cursorX]
	var opening, closing rune
	var isOpening bool

	switch char {
	case '(':
		opening, closing, isOpening = '(', ')', true
	case ')':
		opening, closing, isOpening = '(', ')', false
	case '[':
		opening, closing, isOpening = '[', ']', true
	case ']':
		opening, closing, isOpening = '[', ']', false
	case '{':
		opening, closing, isOpening = '{', '}', true
	case '}':
		opening, closing, isOpening = '{', '}', false
	default:
		return
	}

	if isOpening {
		count := 1
		for y := m.cursorY; y < len(m.lines); y++ {
			lr := []rune(m.lines[y])
			startX := 0
			if y == m.cursorY {
				startX = m.cursorX + 1
			}
			for x := startX; x < len(lr); x++ {
				if lr[x] == opening {
					count++
				} else if lr[x] == closing {
					count--
					if count == 0 {
						m.cursorY = y
						m.cursorX = x
						return
					}
				}
			}
		}
	} else {
		count := 1
		for y := m.cursorY; y >= 0; y-- {
			lr := []rune(m.lines[y])
			endX := len(lr)
			if y == m.cursorY {
				endX = m.cursorX
			}
			for x := endX - 1; x >= 0; x-- {
				if lr[x] == closing {
					count++
				} else if lr[x] == opening {
					count--
					if count == 0 {
						m.cursorY = y
						m.cursorX = x
						return
					}
				}
			}
		}
	}
	m.SetStatusMsg("No matching bracket")
}