package filetree

import (
	"fmt"
	"strings"

	"github.com/charmbracelet/lipgloss"
)

// Styles (will be set from parent)
var (
	DirectoryStyle = lipgloss.NewStyle()
	FileStyle      = lipgloss.NewStyle()
	SelectedStyle  = lipgloss.NewStyle()
)

// View renders the file tree
func (m Model) View(width, height int, focused bool) string {
	var b strings.Builder

	// Calculate visible range for scrolling
	visibleHeight := height - 2 // Account for potential padding
	if visibleHeight < 1 {
		visibleHeight = 1
	}

	startIdx := 0
	if m.Cursor >= visibleHeight {
		startIdx = m.Cursor - visibleHeight + 1
	}

	endIdx := startIdx + visibleHeight
	if endIdx > len(m.Nodes) {
		endIdx = len(m.Nodes)
	}

	for i := startIdx; i < endIdx; i++ {
		node := m.Nodes[i]
		line := m.renderNode(node, i == m.Cursor, focused)

		// Truncate line if too long
		if lipgloss.Width(line) > width-2 {
			line = truncateString(line, width-2)
		}

		// Pad to width
		padding := width - 2 - lipgloss.Width(line)
		if padding > 0 {
			line += strings.Repeat(" ", padding)
		}

		b.WriteString(line)
		if i < endIdx-1 {
			b.WriteString("\n")
		}
	}

	return b.String()
}

func (m Model) renderNode(node *Node, selected, focused bool) string {
	// Build the prefix with tree characters
	prefix := m.buildPrefix(node)

	// Get icon
	icon := getIcon(node)

	// Format name
	name := node.Name
	if node.IsDir {
		name += "/"
	}

	line := fmt.Sprintf("%s%s %s", prefix, icon, name)

	// Apply style
	if selected && focused {
		return SelectedStyle.Render(line)
	} else if selected {
		return lipgloss.NewStyle().Foreground(lipgloss.Color("#666666")).Render(line)
	} else if node.IsDir {
		return DirectoryStyle.Render(line)
	}
	return FileStyle.Render(line)
}

func (m Model) buildPrefix(node *Node) string {
	if node.Level == 0 {
		return ""
	}

	// Build prefix by traversing parents
	prefixParts := make([]string, node.Level)

	current := node
	for i := node.Level - 1; i >= 0; i-- {
		parent := current.Parent
		if parent == nil {
			prefixParts[i] = "  "
			continue
		}

		isLast := true
		for j, sibling := range parent.Children {
			if sibling == current {
				isLast = j == len(parent.Children)-1
				break
			}
		}

		if i == node.Level-1 {
			if isLast {
				prefixParts[i] = "└─"
			} else {
				prefixParts[i] = "├─"
			}
		} else {
			if isLast {
				prefixParts[i] = "  "
			} else {
				prefixParts[i] = "│ "
			}
		}

		current = parent
	}

	return strings.Join(prefixParts, "")
}

func getIcon(node *Node) string {
	if node.IsDir {
		if node.IsOpen {
			return "▼"
		}
		return "▶"
	}

	// Minimal icons using Unicode block/geometric characters
	// Grouped by file type category
	ext := node.Ext()

	// Documents
	docs := map[string]bool{".md": true, ".markdown": true, ".txt": true, ".pdf": true, ".doc": true, ".docx": true}
	if docs[ext] {
		return "◔"
	}

	// Code files
	code := map[string]bool{
		".go": true, ".py": true, ".js": true, ".ts": true, ".jsx": true, ".tsx": true,
		".rs": true, ".c": true, ".cpp": true, ".h": true, ".hpp": true,
		".java": true, ".rb": true, ".php": true, ".swift": true, ".kt": true,
		".scala": true, ".ex": true, ".exs": true, ".clj": true, ".zig": true,
		".nim": true, ".lua": true, ".vim": true, ".el": true,
	}
	if code[ext] {
		return "◇"
	}

	// Shell/scripts
	shell := map[string]bool{".sh": true, ".bash": true, ".zsh": true, ".fish": true}
	if shell[ext] {
		return "▷"
	}

	// Data/config
	data := map[string]bool{
		".json": true, ".yaml": true, ".yml": true, ".toml": true,
		".xml": true, ".csv": true, ".sql": true, ".env": true,
	}
	if data[ext] {
		return "◫"
	}

	// Web
	web := map[string]bool{".html": true, ".css": true, ".scss": true, ".sass": true, ".less": true}
	if web[ext] {
		return "◈"
	}

	// Images
	images := map[string]bool{".png": true, ".jpg": true, ".jpeg": true, ".gif": true, ".svg": true, ".webp": true}
	if images[ext] {
		return "◐"
	}

	// Default
	return "○"
}

func truncateString(s string, maxWidth int) string {
	if lipgloss.Width(s) <= maxWidth {
		return s
	}

	// Simple truncation - could be improved for unicode
	runes := []rune(s)
	for i := len(runes) - 1; i >= 0; i-- {
		truncated := string(runes[:i]) + "…"
		if lipgloss.Width(truncated) <= maxWidth {
			return truncated
		}
	}
	return "…"
}