package tui

import (
	"strings"

	"github.com/charmbracelet/lipgloss"
)

// Responsive breakpoints
const (
	widthCompact = 60  // mobile / Termux
	widthMedium  = 100 // tablet
)

// boxOverhead is the horizontal chars consumed by BorderStyle (border 2 + padding 4)
const boxOverhead = 6

// wrapFooter wraps a footer string into multiple lines that fit availW.
// Words are split on double-space separators ("  ") and grouped greedily.
// Returns the wrapped string with "\n" line breaks.
func wrapFooter(text string, availW int) string {
	if availW < 1 {
		availW = 1
	}
	if lipgloss.Width(text) <= availW {
		return text
	}

	words := strings.Split(text, "  ")
	var lines []string
	var current strings.Builder

	for _, word := range words {
		word = strings.TrimSpace(word)
		if word == "" {
			continue
		}
		if current.Len() == 0 {
			current.WriteString(word)
		} else if current.Len()+2+lipgloss.Width(word) <= availW {
			current.WriteString("  ")
			current.WriteString(word)
		} else {
			lines = append(lines, current.String())
			current.Reset()
			current.WriteString(word)
		}
	}
	if current.Len() > 0 {
		lines = append(lines, current.String())
	}

	return strings.Join(lines, "\n")
}

// adaptiveSidePad returns horizontal padding based on terminal width.
// wide: 6, medium: 3, compact: 1
func adaptiveSidePad(termWidth int) int {
	switch {
	case termWidth < widthCompact:
		return 1
	case termWidth < widthMedium:
		return 3
	default:
		return 6
	}
}

// clampWidth clamps a target box width to fit within the terminal.
// Reserves boxOverhead for border+padding. Enforces a minimum of 20.
func clampWidth(target, termWidth int) int {
	maxW := termWidth - boxOverhead
	if maxW < 20 {
		maxW = 20
	}
	if target > maxW {
		return maxW
	}
	if target < 20 {
		return 20
	}
	return target
}

// truncateStr truncates a string to maxLen with an ellipsis character.
func truncateStr(s string, maxLen int) string {
	if maxLen < 1 {
		return ""
	}
	if lipgloss.Width(s) <= maxLen {
		return s
	}
	if maxLen <= 1 {
		return "…"
	}
	runes := []rune(s)
	var result []rune
	resultW := 0
	for _, r := range runes {
		rw := lipgloss.Width(string(r))
		if resultW+rw > maxLen-1 {
			break
		}
		result = append(result, r)
		resultW += rw
	}
	return string(result) + "…"
}

// Exported wrappers for testing

// WrapFooter wraps a footer string into multiple lines that fit availW
func WrapFooter(text string, availW int) string {
	return wrapFooter(text, availW)
}

// ClampWidth clamps a target box width to fit within the terminal
func ClampWidth(target, termWidth int) int {
	return clampWidth(target, termWidth)
}

// TruncateStr truncates a string to maxLen with an ellipsis character
func TruncateStr(s string, maxLen int) string {
	return truncateStr(s, maxLen)
}