package video

import (
	"fmt"
	"sort"

	"mxl-pattern-generator/kernels"
)

type PatternInfo struct {
	Name        string
	Description string
}

type pattern struct {
	PatternInfo
	kernelSource string
	dynamic      bool
}

var patterns = map[string]pattern{
	"ebu75": {
		PatternInfo:  PatternInfo{Name: "ebu75", Description: "EBU 75% Color Bar Signal"},
		kernelSource: mustReadKernel("static/ebu75.wgsl"),
	},
	"ebu75-move": {
		PatternInfo:  PatternInfo{Name: "ebu75-move", Description: "EBU 75% Color Bar Signal with moving square"},
		kernelSource: mustReadKernel("dynamic/ebu75.wgsl"),
		dynamic:      true,
	},
	"ebu100": {
		PatternInfo:  PatternInfo{Name: "ebu100", Description: "EBU 100% Color Bar Signal"},
		kernelSource: mustReadKernel("static/ebu100.wgsl"),
	},
	"ebu100-move": {
		PatternInfo:  PatternInfo{Name: "ebu100-move", Description: "EBU 100% Color Bar Signal with moving square"},
		kernelSource: mustReadKernel("dynamic/ebu100.wgsl"),
		dynamic:      true,
	},
	"smpte": {
		PatternInfo:  PatternInfo{Name: "smpte", Description: "SMPTE RP-219 Color Bar Signal"},
		kernelSource: mustReadKernel("static/smpteBars.wgsl"),
	},
	"smpte-move": {
		PatternInfo:  PatternInfo{Name: "smpte-move", Description: "SMPTE RP-219 Color Bar Signal with moving square"},
		kernelSource: mustReadKernel("dynamic/smpteBars.wgsl"),
		dynamic:      true,
	},
	"gray-bars": {
		PatternInfo:  PatternInfo{Name: "gray-bars", Description: "13-step grayscale bars (Y 64..940)"},
		kernelSource: mustReadKernel("static/yBars.wgsl"),
	},
	"gray-bars-move": {
		PatternInfo:  PatternInfo{Name: "gray-bars-move", Description: "13-step grayscale bars (Y 64..940) with moving square"},
		kernelSource: mustReadKernel("dynamic/yBars.wgsl"),
		dynamic:      true,
	},
	"gray-ramp": {
		PatternInfo:  PatternInfo{Name: "gray-ramp", Description: "Y gradient (black -> 100% white)"},
		kernelSource: mustReadKernel("static/yRamp.wgsl"),
	},
	"gray-ramp-move": {
		PatternInfo:  PatternInfo{Name: "gray-ramp-move", Description: "Y gradient with moving square"},
		kernelSource: mustReadKernel("dynamic/yRamp.wgsl"),
		dynamic:      true,
	},
}

func mustReadKernel(name string) string {
	source, err := kernels.Read(name)
	if err != nil {
		panic(fmt.Sprintf("read embedded video kernel %q: %v", name, err))
	}
	return string(source)
}

func HasPattern(name string) bool {
	_, ok := patterns[name]
	return ok
}

func Patterns() []PatternInfo {
	result := make([]PatternInfo, 0, len(patterns))
	for _, pattern := range patterns {
		result = append(result, pattern.PatternInfo)
	}
	sort.Slice(result, func(i, j int) bool {
		return result[i].Name < result[j].Name
	})
	return result
}