// Copyright 2024 The Ebitengine Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//go:build ignore

// This program generates platform-specific controller dbs. It can be invoked by running
// go generate
package main

import (
	"bytes"
	_ "embed"
	"fmt"
	"log"
	"os"
	"path/filepath"
	"strings"
	"text/template"
)

const license = `// Copyright 2024 The Ebitengine Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
`

// gamecontrollerdb.txt is downloaded at https://github.com/mdqinc/SDL_GameControllerDB.

// To update the database file, run:
//
//     curl --location --remote-name https://raw.githubusercontent.com/mdqinc/SDL_GameControllerDB/master/gamecontrollerdb.txt

//go:embed gamecontrollerdb.txt
var gamecontrollerdb_txt []byte

// additional GLFW gamepads for Windows
var additionalGLFWGamepads = []byte(`
78696e70757401000000000000000000,XInput Gamepad (GLFW),platform:Windows,a:b0,b:b1,x:b2,y:b3,leftshoulder:b4,rightshoulder:b5,back:b6,start:b7,leftstick:b8,rightstick:b9,leftx:a0,lefty:a1,rightx:a2,righty:a3,lefttrigger:a4,righttrigger:a5,dpup:h0.1,dpright:h0.2,dpdown:h0.4,dpleft:h0.8,
78696e70757402000000000000000000,XInput Wheel (GLFW),platform:Windows,a:b0,b:b1,x:b2,y:b3,leftshoulder:b4,rightshoulder:b5,back:b6,start:b7,leftstick:b8,rightstick:b9,leftx:a0,lefty:a1,rightx:a2,righty:a3,lefttrigger:a4,righttrigger:a5,dpup:h0.1,dpright:h0.2,dpdown:h0.4,dpleft:h0.8,
78696e70757403000000000000000000,XInput Arcade Stick (GLFW),platform:Windows,a:b0,b:b1,x:b2,y:b3,leftshoulder:b4,rightshoulder:b5,back:b6,start:b7,leftstick:b8,rightstick:b9,leftx:a0,lefty:a1,rightx:a2,righty:a3,lefttrigger:a4,righttrigger:a5,dpup:h0.1,dpright:h0.2,dpdown:h0.4,dpleft:h0.8,
78696e70757404000000000000000000,XInput Flight Stick (GLFW),platform:Windows,a:b0,b:b1,x:b2,y:b3,leftshoulder:b4,rightshoulder:b5,back:b6,start:b7,leftstick:b8,rightstick:b9,leftx:a0,lefty:a1,rightx:a2,righty:a3,lefttrigger:a4,righttrigger:a5,dpup:h0.1,dpright:h0.2,dpdown:h0.4,dpleft:h0.8,
78696e70757405000000000000000000,XInput Dance Pad (GLFW),platform:Windows,a:b0,b:b1,x:b2,y:b3,leftshoulder:b4,rightshoulder:b5,back:b6,start:b7,leftstick:b8,rightstick:b9,leftx:a0,lefty:a1,rightx:a2,righty:a3,lefttrigger:a4,righttrigger:a5,dpup:h0.1,dpright:h0.2,dpdown:h0.4,dpleft:h0.8,
78696e70757406000000000000000000,XInput Guitar (GLFW),platform:Windows,a:b0,b:b1,x:b2,y:b3,leftshoulder:b4,rightshoulder:b5,back:b6,start:b7,leftstick:b8,rightstick:b9,leftx:a0,lefty:a1,rightx:a2,righty:a3,lefttrigger:a4,righttrigger:a5,dpup:h0.1,dpright:h0.2,dpdown:h0.4,dpleft:h0.8,
78696e70757408000000000000000000,XInput Drum Kit (GLFW),platform:Windows,a:b0,b:b1,x:b2,y:b3,leftshoulder:b4,rightshoulder:b5,back:b6,start:b7,leftstick:b8,rightstick:b9,leftx:a0,lefty:a1,rightx:a2,righty:a3,lefttrigger:a4,righttrigger:a5,dpup:h0.1,dpright:h0.2,dpdown:h0.4,dpleft:h0.8,
`)

//go:generate go run gen_dbs.go
func main() {
	// Follow the standard comment rule (https://pkg.go.dev/cmd/go#hdr-Generate_Go_files_by_processing_source).
	doNotEdit := "// Code generated by gen_dbs.go using 'go generate'. DO NOT EDIT."

	type gamePadPlatform struct {
		genFileName string
		buildTag    string
	}

	supported := map[string]gamePadPlatform{
		"Windows": {
			genFileName: "windows",
			buildTag:    "//go:build windows && !microsoftgdk",
		},
		"Mac OS X": {
			genFileName: "macos_darwin",
			buildTag:    "//go:build darwin && !ios",
		},
		"Linux": {
			genFileName: "linbsd",
			buildTag:    "//go:build (freebsd || (linux && !android) || netbsd || openbsd) && !nintendosdk && !playstation5",
		},
		"iOS": {
			genFileName: "ios",
			buildTag:    "//go:build ios",
		},
		"Android": {
			genFileName: "android",
			buildTag:    "//go:build android",
		},
	}

	tmpl, err := template.ParseFiles("gamepaddb_tmpl.tpl")
	if err != nil {
		log.Fatal(err)
	}

	controllerDbs := splitControllerDb(gamecontrollerdb_txt)

	for sdlName, platform := range supported {
		path := filepath.Join("internal", "gamepaddb", fmt.Sprintf("db_%s.go", platform.genFileName))
		f, err := os.Create(path)
		if err != nil {
			log.Fatal(err)
		}
		defer f.Close()

		controllerDb, ok := controllerDbs[sdlName]
		if !ok {
			log.Fatalf("failed to find controller db for platform %s in gamecontrollerdb_txt", sdlName)
		}

		err = tmpl.Execute(f, struct {
			License         string
			DoNotEdit       string
			BuildTag        string
			SDLPlatform     string
			ControllerBytes []byte
			GLFWGamePads    []byte
		}{
			License:         license,
			DoNotEdit:       doNotEdit,
			BuildTag:        platform.buildTag,
			SDLPlatform:     sdlName,
			ControllerBytes: controllerDb,
			GLFWGamePads:    additionalGLFWGamepads,
		})
		if err != nil {
			log.Fatal(err)
		}
	}
}

// splitControllerDb maps the game controller db into respective controller definition byte slices for
// each platform
func splitControllerDb(controllerDb []byte) map[string][]byte {
	dbs := map[string][]byte{}
	// split at #, skip first 3 header chunks
	chunks := bytes.Split(controllerDb, []byte{'#'})[3:]

	for _, chunk := range chunks {
		// find each platform string
		lines := bytes.Split(chunk, []byte{'\n'})
		if len(lines) == 0 {
			continue
		}

		platform := strings.TrimSpace(string(lines[0]))
		// count platform string len + space + newline
		bytesRead := len(lines[0]) + 1
		dbs[platform] = chunk[bytesRead:]
	}
	return dbs
}