package gfx

import (
	"io/fs"
	"os"
	"path/filepath"

	"github.com/chompy/roguelike_rpg/internal/util"
	"github.com/hajimehoshi/ebiten/v2/text/v2"
)

type FontDef struct {
	Path    string   `yaml:"path"`
	Size    int      `yaml:"size"`
	Effects []string `yaml:"effects"`
}

type FontLibrary map[string]*Font

func LoadFontLibrary(assetFS fs.FS) (FontLibrary, error) {
	// load fonts.yaml
	fontLibraryConf := make(map[string]FontDef)
	if err := util.ReadYAML(assetFS, filepath.Join("gfx", "fonts.yaml"), &fontLibraryConf); err != nil {
		return nil, err
	}

	// preload fonts and effects
	fontSources := make(map[string]*text.GoTextFaceSource)
	effects := make(map[string]Effect)
	for _, fontDef := range fontLibraryConf {
		if fontSources[fontDef.Path] == nil && fontDef.Path != "" {
			fontReader, err := assetFS.Open(fontDef.Path)
			if err != nil {
				return nil, err
			}
			defer fontReader.Close()
			fontSource, err := text.NewGoTextFaceSource(fontReader)
			if err != nil {
				return nil, err
			}
			fontSources[fontDef.Path] = fontSource
		}
		for _, effectName := range fontDef.Effects {
			if effects[effectName] == nil {
				luaEffect, err := LoadLuaEffect(assetFS, effectName)
				if err != nil && !os.IsNotExist(err) {
					return nil, err
				}
				if err == nil {
					effects[effectName] = luaEffect
					continue
				}
				shaderEffect, err := LoadShaderEffect(assetFS, effectName)
				if err != nil && !os.IsNotExist(err) {
					return nil, err
				}
				if err == nil {
					effects[effectName] = shaderEffect
					continue
				}
			}
		}

	}

	fontLibrary := make(FontLibrary, 0)
	for name, fontDef := range fontLibraryConf {
		fontSource := fontSources[fontDef.Path]
		if fontSource == nil {
			continue
		}
		fontEffects := make([]Effect, 0)
		for _, effectName := range fontDef.Effects {
			if effects[effectName] != nil {
				fontEffects = append(fontEffects, effects[effectName])
			}
		}
		fontLibrary[name] = &Font{
			Font:    &text.GoTextFace{Source: fontSource, Size: float64(fontDef.Size)},
			effects: fontEffects,
		}
	}
	return fontLibrary, nil
}

func (l FontLibrary) Get(names ...string) ([]*Font, error) {
	out := make([]*Font, 0)
	for _, name := range names {
		if l[name] == nil {
			return nil, ErrFontNotDefined
		}
		out = append(out, l[name])
	}
	return out, nil
}

func (l FontLibrary) GetOne(name string) (*Font, error) {
	if l[name] != nil {
		return l[name], nil
	}
	return nil, ErrFontNotDefined
}