// Package vision provides computer vision utilities for game screen analysis.
//
// Uses GoCV (OpenCV bindings for Go) for template matching, color detection,
// and contour analysis. Designed for high-throughput real-time analysis.
package vision

import (
	"image"
	"image/color"
)

// Match represents a detected element on screen.
type Match struct {
	Position   image.Point
	BBox       image.Rectangle
	Confidence float64
	Label      string
}

// Template is a pre-loaded image template for matching.
type Template struct {
	Name   string
	Image  image.Image
	Width  int
	Height int
}

// ColorRange defines an HSV color range for detection.
type ColorRange struct {
	LowerH, LowerS, LowerV int
	UpperH, UpperS, UpperV int
}

// Pipeline processes frames through a series of vision operations.
type Pipeline struct {
	templates  map[string]*Template
	threshold  float64
}

// NewPipeline creates a vision pipeline with the given confidence threshold.
func NewPipeline(threshold float64) *Pipeline {
	return &Pipeline{
		templates: make(map[string]*Template),
		threshold: threshold,
	}
}

// LoadTemplate loads a template image for matching.
func (p *Pipeline) LoadTemplate(name string, img image.Image) {
	bounds := img.Bounds()
	p.templates[name] = &Template{
		Name:   name,
		Image:  img,
		Width:  bounds.Dx(),
		Height: bounds.Dy(),
	}
}

// FindTemplate searches for a template in the frame.
// Returns the best match above threshold, or nil.
func (p *Pipeline) FindTemplate(frame image.Image, templateName string) *Match {
	// TODO: Implement with GoCV matchTemplate
	// This is a stub — actual implementation needs gocv.MatchTemplate
	return nil
}

// FindAllTemplates finds all matches of a template above threshold.
func (p *Pipeline) FindAllTemplates(frame image.Image, templateName string) []Match {
	// TODO: Implement with GoCV + NMS
	return nil
}

// FindByColor detects regions matching an HSV color range.
func (p *Pipeline) FindByColor(frame image.Image, colorRange ColorRange, minArea int) []Match {
	// TODO: Implement with GoCV inRange + findContours
	return nil
}

// ReadBarPercentage reads a horizontal bar's fill level (health, mana, xp).
func (p *Pipeline) ReadBarPercentage(frame image.Image, barRegion image.Rectangle, filledColor ColorRange) float64 {
	// TODO: Implement — scan columns for filled color ratio
	return 0.0
}

// GetPixelColor returns the color at a specific pixel.
func (p *Pipeline) GetPixelColor(frame image.Image, x, y int) color.Color {
	return frame.At(x, y)
}