package service

import (
	"fmt"
	"math"
	"strings"

	"materialanalyzer/internal/model"
)

func BuildSemantic(p model.Product, visual model.VisualFeatures, texture model.TextureFeatures) model.SemanticFeatures {
	family := MaterialFamily(p.Category, p.Material)
	color := colorFamily(visual.DominantRGB)
	finish := strings.TrimSpace(p.Finish)
	if finish == "" {
		finish = inferFinish(visual, texture)
	}
	variation := variationLevel(visual, texture)
	style := visualStyle(family, p, visual)
	grain := grainLabel(family, p, texture)

	description := fmt.Sprintf("%s %s %s flooring with %s finish, %s visual variation, and %s texture direction.",
		color, strings.ToLower(style), cleanMaterialLabel(p), strings.ToLower(finish), strings.ToLower(variation), strings.ToLower(grain))

	tags := []string{family, color, style, finish, variation}
	if p.ColorTone != "" {
		tags = append(tags, p.ColorTone)
	}
	if p.Material != "" {
		tags = append(tags, p.Material)
	}

	return model.SemanticFeatures{
		Provider:      "local_rules_v2",
		Model:         "rule_based",
		Description:   description,
		MaterialType:  family,
		SurfaceFinish: finish,
		GrainType:     grain,
		ColorFamily:   color,
		VisualStyle:   style,
		Variation:     variation,
		GlossLevel:    glossLevel(finish, visual),
		Grain:         grain,
		Tags:          compactStrings(tags),
		Confidence:    0.72,
		FieldConfidence: map[string]float64{
			"description":    0.68,
			"material_type":  0.85,
			"surface_finish": confidenceFromSource(p.Finish),
			"grain_type":     0.62,
			"color_family":   0.88,
			"visual_style":   0.72,
			"variation":      0.74,
			"gloss_level":    0.65,
		},
	}
}

func MaterialFamily(category, material string) string {
	cat := strings.ToLower(category)
	mat := strings.ToLower(material)
	text := cat + " " + mat
	switch {
	case containsAnyText(text, "spc", "lvp", "wpc", "luxury vinyl", "vinyl", "rigid core", "pvc"):
		return "vinyl"
	case containsAnyText(text, "porcelain", "ceramic", "tile"):
		if containsAnyText(mat, "stone", "marble", "travertine", "slate", "limestone", "granite", "terrazzo") {
			return "stone_tile"
		}
		return "tile"
	case containsAnyText(text, "stone", "marble", "travertine", "slate", "limestone"):
		return "stone_tile"
	case containsAnyText(text, "hardwood", "engineered", "laminate", "oak", "maple", "hickory", "walnut", "pine", "birch", "cherry", "acacia", "bamboo"):
		return "wood"
	default:
		return "generic"
	}
}

func cleanMaterialLabel(p model.Product) string {
	for _, candidate := range []string{p.Material, p.Category, "material"} {
		candidate = strings.TrimSpace(candidate)
		if candidate != "" {
			return candidate
		}
	}
	return "material"
}

func colorFamily(rgb model.RGB) string {
	r, g, b := float64(rgb.R), float64(rgb.G), float64(rgb.B)
	maxV := math.Max(r, math.Max(g, b))
	minV := math.Min(r, math.Min(g, b))
	brightness := maxV / 255.0
	chroma := (maxV - minV) / 255.0
	if brightness < 0.18 {
		return "Black"
	}
	if brightness > 0.86 && chroma < 0.10 {
		return "White"
	}
	if chroma < 0.08 {
		if brightness < 0.42 {
			return "Dark Gray"
		}
		if brightness > 0.72 {
			return "Light Gray"
		}
		return "Gray"
	}
	if r > g*1.08 && g > b*1.05 {
		if brightness > 0.65 {
			return "Honey"
		}
		return "Brown"
	}
	if r > 150 && g > 125 && b > 95 && math.Abs(r-g) < 45 {
		return "Beige"
	}
	if b > r && b > g {
		return "Cool Gray"
	}
	return "Natural"
}

func inferFinish(visual model.VisualFeatures, texture model.TextureFeatures) string {
	if visual.Contrast < 0.12 && texture.TextureFrequency < 0.18 {
		return "Matte"
	}
	if visual.Brightness > 0.72 && texture.EdgeDensity < 0.08 {
		return "Satin"
	}
	return "Textured"
}

func glossLevel(finish string, visual model.VisualFeatures) string {
	lower := strings.ToLower(finish)
	switch {
	case strings.Contains(lower, "gloss"):
		return "High"
	case strings.Contains(lower, "satin"):
		return "Medium"
	case strings.Contains(lower, "matte"):
		return "Low"
	case visual.Brightness > 0.72 && visual.Contrast < 0.12:
		return "Medium"
	default:
		return "Low"
	}
}

func confidenceFromSource(v string) float64 {
	if strings.TrimSpace(v) == "" {
		return 0.55
	}
	return 0.88
}

func variationLevel(visual model.VisualFeatures, texture model.TextureFeatures) string {
	colorDistance := 0.0
	if visual.DominantRGB != visual.SecondaryRGB {
		dr := float64(visual.DominantRGB.R - visual.SecondaryRGB.R)
		dg := float64(visual.DominantRGB.G - visual.SecondaryRGB.G)
		db := float64(visual.DominantRGB.B - visual.SecondaryRGB.B)
		colorDistance = math.Sqrt(dr*dr+dg*dg+db*db) / 441.67
	}
	score := visual.Contrast*0.45 + texture.EdgeDensity*0.35 + colorDistance*0.20
	switch {
	case score > 0.20 || texture.Entropy > 7.35:
		return "High"
	case score > 0.11 || texture.Entropy > 6.55:
		return "Medium"
	default:
		return "Low"
	}
}

func visualStyle(family string, p model.Product, visual model.VisualFeatures) string {
	text := strings.ToLower(p.StyleName + " " + p.Material + " " + p.Category + " " + p.ColorTone)
	switch family {
	case "wood", "vinyl":
		if containsAnyText(text, "weathered", "distressed", "reclaimed", "rustic") {
			return "Rustic"
		}
		if containsAnyText(text, "oak", "hickory", "maple", "pine", "walnut", "cherry") {
			return "Natural Wood"
		}
	case "tile", "stone_tile":
		if containsAnyText(text, "oak", "hickory", "maple", "pine", "walnut", "wood") {
			return "Wood Look Tile"
		}
		if containsAnyText(text, "marble") {
			return "Marble"
		}
		if containsAnyText(text, "slate", "travertine", "limestone", "stone") {
			return "Natural Stone"
		}
		return "Contemporary Tile"
	}
	if visual.Saturation < 0.12 {
		return "Neutral"
	}
	return "Natural"
}

func grainLabel(family string, p model.Product, texture model.TextureFeatures) string {
	if family == "tile" || family == "stone_tile" {
		text := strings.ToLower(p.Material + " " + p.StyleName)
		if containsAnyText(text, "oak", "hickory", "maple", "pine", "walnut", "wood") {
			return orientationLabel(texture.PrimaryOrientationDeg) + " " + inferSpecies(p)
		}
		if texture.OrientationVariance < 0.38 {
			return orientationLabel(texture.PrimaryOrientationDeg) + " Vein"
		}
		return "Mixed Vein"
	}
	species := inferSpecies(p)
	direction := orientationLabel(texture.PrimaryOrientationDeg)
	if texture.OrientationVariance > 0.70 {
		return "Mixed " + species
	}
	return direction + " " + species
}

func inferSpecies(p model.Product) string {
	text := strings.ToLower(p.WoodSpecies + " " + p.Material + " " + p.StyleName)
	for _, s := range []string{"oak", "maple", "hickory", "walnut", "pine", "birch", "cherry", "acacia", "bamboo", "ash", "elm", "teak"} {
		if strings.Contains(text, s) {
			return strings.Title(s)
		}
	}
	return "Grain"
}

func orientationLabel(deg float64) string {
	switch {
	case deg < 22.5 || deg >= 157.5:
		return "Horizontal"
	case deg < 67.5:
		return "Diagonal"
	case deg < 112.5:
		return "Vertical"
	default:
		return "Diagonal"
	}
}

func compactStrings(values []string) []string {
	seen := map[string]bool{}
	out := make([]string, 0, len(values))
	for _, v := range values {
		v = strings.TrimSpace(v)
		if v == "" {
			continue
		}
		key := strings.ToLower(v)
		if seen[key] {
			continue
		}
		seen[key] = true
		out = append(out, v)
	}
	return out
}

func containsAnyText(text string, needles ...string) bool {
	for _, needle := range needles {
		if strings.Contains(text, needle) {
			return true
		}
	}
	return false
}