package d2sketch

import (
	
	
	

	
	rough 
)

// ScenePath is the renderer-neutral form of one ordered rough-go operation
// set. Paint remains a string so callers can resolve D2 theme colors before
// constructing scene paint.
type ScenePath struct {
	Path        d2scene.Path
	Fill        string
	Stroke      string
	StrokeWidth float64
	Dash        []float64
	DashOffset  float64
}

// SceneLimits bounds conversion work after rough-go has generated a drawable.
// D2 callers must additionally charge the generated commands against their
// document-wide scene/path budget.
type SceneLimits struct {
	MaxSets int
	MaxOps  int
}

// CompileScenePaths translates the rough-go operation types emitted by D2 into
// typed scene paths. It rejects path2D operation sets.
func ( context.Context,  rough.Drawable,  SceneLimits) ([]ScenePath, error) {
	if  == nil {
		 = context.Background()
	}
	if .MaxSets <= 0 || .MaxOps <= 0 {
		return nil, fmt.Errorf("d2sketch: scene conversion limits must be positive")
	}
	if len(.Sets) > .MaxSets {
		return nil, fmt.Errorf("d2sketch: rough operation set count %d exceeds limit %d", len(.Sets), .MaxSets)
	}
	 := 0
	for ,  := range .Sets {
		if len(.Ops) > .MaxOps- {
			return nil, fmt.Errorf("d2sketch: rough operation count exceeds limit %d at set %d", .MaxOps, )
		}
		 += len(.Ops)
	}
	if  := .Err();  != nil {
		return nil, 
	}

	 := .Options
	if  == nil {
		return nil, fmt.Errorf("d2sketch: rough drawable has no resolved options")
	}
	if .FixedDecimalPlaceDigits != nil {
		return nil, fmt.Errorf("d2sketch: fixed-decimal rough output is unsupported in typed scene conversion")
	}
	 := make([]ScenePath, 0, len(.Sets))
	 := 0
	for ,  := range .Sets {
		if  := .Err();  != nil {
			return nil, 
		}
		switch .Type {
		case rough.OpSetPath, rough.OpSetFillPath, rough.OpSetFillSketch:
		case rough.OpSetPath2DFill, rough.OpSetPath2DPattern:
			return nil, fmt.Errorf("d2sketch: SVG path2D operation type %q is unsupported in typed scene conversion", .Type)
		default:
			return nil, fmt.Errorf("d2sketch: unknown rough operation type %q", .Type)
		}
		// Empty fill sets have no drawable segment, such as a small filled-diamond
		// arrowhead at a wide stroke. Skip them without creating an invalid scene
		// path; the limits above still account for the complete drawable.
		if len(.Ops) == 0 {
			continue
		}
		,  := compileRoughOperationSet(, , &)
		if  != nil {
			return nil, fmt.Errorf("d2sketch: rough operation set %d: %w", , )
		}
		 := ScenePath{Path: }
		switch .Type {
		case rough.OpSetPath:
			.Fill = "none"
			.Stroke = noneIfEmpty(.Stroke)
			.StrokeWidth = .StrokeWidth
			.Dash = append([]float64(nil), .StrokeLineDash...)
			.DashOffset = .StrokeLineDashOffset
		case rough.OpSetFillPath:
			.Fill = noneIfEmpty(.Fill)
			.Stroke = "none"
		case rough.OpSetFillSketch:
			.Fill = "none"
			.Stroke = noneIfEmpty(.Fill)
			.StrokeWidth = .FillWeight
			if .StrokeWidth < 0 {
				.StrokeWidth = .StrokeWidth / 2
			}
			.Dash = append([]float64(nil), .FillLineDash...)
			.DashOffset = .FillLineDashOffset
		}
		if  := validateScenePathStyle();  != nil {
			return nil, fmt.Errorf("d2sketch: rough operation set %d: %w", , )
		}
		 = append(, )
	}
	if  := .Err();  != nil {
		return nil, 
	}
	return , nil
}

func compileRoughOperationSet( context.Context,  rough.OpSet,  *int) (d2scene.Path, error) {
	 := make([]d2scene.PathCommand, 0, len(.Ops))
	for ,  := range .Ops {
		if *&255 == 0 {
			if  := .Err();  != nil {
				return d2scene.Path{}, 
			}
		}
		(*)++
		,  := finiteRoughData(.Data)
		if  != nil {
			return d2scene.Path{}, fmt.Errorf("operation %d %q: %w", , .Op, )
		}
		switch .Op {
		case rough.OpMove:
			if len() != 2 {
				return d2scene.Path{}, roughArityError(, .Op, len(), 2)
			}
			 = append(, d2scene.MoveTo([0], [1]))
		case rough.OpLineTo:
			if len() != 2 {
				return d2scene.Path{}, roughArityError(, .Op, len(), 2)
			}
			 = append(, d2scene.LineTo([0], [1]))
		case rough.OpBCurveTo:
			if len() != 6 {
				return d2scene.Path{}, roughArityError(, .Op, len(), 6)
			}
			 = append(, d2scene.CubicTo([0], [1], [2], [3], [4], [5]))
		case rough.OpQCurveTo:
			if len() != 4 {
				return d2scene.Path{}, roughArityError(, .Op, len(), 4)
			}
			 = append(, d2scene.QuadraticTo([0], [1], [2], [3]))
		default:
			return d2scene.Path{}, fmt.Errorf("operation %d has unsupported verb %q", , .Op)
		}
	}
	if len() == 0 {
		return d2scene.Path{}, fmt.Errorf("operation set is empty")
	}
	return d2scene.Path{Commands: }, nil
}

func finiteRoughData( []float64) ([]float64, error) {
	 := make([]float64, len())
	for ,  := range  {
		if math.IsNaN() || math.IsInf(, 0) {
			return nil, fmt.Errorf("coordinate %d is not finite", )
		}
		// Normalize generated coordinates to six decimal places without
		// serializing and reparsing a path string.
		 :=  * 1_000_000
		if math.IsInf(, 0) {
			return nil, fmt.Errorf("coordinate %d is too large for six-place normalization", )
		}
		[] = math.Trunc() / 1_000_000
	}
	return , nil
}

func roughArityError( int,  rough.OpType, ,  int) error {
	return fmt.Errorf("operation %d %q has %d coordinates, want %d", , , , )
}

func noneIfEmpty( string) string {
	if  == "" {
		return "none"
	}
	return 
}

func validateScenePathStyle( ScenePath) error {
	if math.IsNaN(.StrokeWidth) || math.IsInf(.StrokeWidth, 0) || .StrokeWidth < 0 {
		return fmt.Errorf("stroke width must be finite and non-negative")
	}
	if math.IsNaN(.DashOffset) || math.IsInf(.DashOffset, 0) {
		return fmt.Errorf("dash offset must be finite")
	}
	for ,  := range .Dash {
		if math.IsNaN() || math.IsInf(, 0) ||  < 0 {
			return fmt.Errorf("dash %d must be finite and non-negative", )
		}
	}
	return nil
}