Refactor codebase, introduce relaymode package, update constants and improve consistency

- Refactor constant definitions and organization
- Clean up package level variables and functions
- Introduce new `relaymode` and `apitype` packages for constant definitions
- Refactor and simplify code in several packages including `openai`, `relay/channel/baidu`, `relay/util`, `relay/controller`, `relay/channeltype`
- Add helper functions in `relay/channeltype` package to convert channel type constants to corresponding API type constants
- Remove deprecated functions such as `ResponseText2Usage` from `relay/channel/openai/helper.go`
- Modify code in `relay/util/validation.go` and related files to use new `validator.ValidateTextRequest` function
- Rename `util` package to `relaymode` and update related imports in several packages

relay/channeltype/define.go

@@ -0,0 +1,39 @@
+package channeltype
+
+const (
+	Unknown = iota
+	OpenAI
+	API2D
+	Azure
+	CloseAI
+	OpenAISB
+	OpenAIMax
+	OhMyGPT
+	Custom
+	Ails
+	AIProxy
+	PaLM
+	API2GPT
+	AIGC2D
+	Anthropic
+	Baidu
+	Zhipu
+	Ali
+	Xunfei
+	AI360
+	OpenRouter
+	AIProxyLibrary
+	FastGPT
+	Tencent
+	Gemini
+	Moonshot
+	Baichuan
+	Minimax
+	Mistral
+	Groq
+	Ollama
+	LingYiWanWu
+	StepFun
+
+	Dummy
+)

relay/channeltype/helper.go

@@ -0,0 +1,30 @@
+package channeltype
+
+import "github.com/songquanpeng/one-api/relay/apitype"
+
+func ToAPIType(channelType int) int {
+	apiType := apitype.OpenAI
+	switch channelType {
+	case Anthropic:
+		apiType = apitype.Anthropic
+	case Baidu:
+		apiType = apitype.Baidu
+	case PaLM:
+		apiType = apitype.PaLM
+	case Zhipu:
+		apiType = apitype.Zhipu
+	case Ali:
+		apiType = apitype.Ali
+	case Xunfei:
+		apiType = apitype.Xunfei
+	case AIProxyLibrary:
+		apiType = apitype.AIProxyLibrary
+	case Tencent:
+		apiType = apitype.Tencent
+	case Gemini:
+		apiType = apitype.Gemini
+	case Ollama:
+		apiType = apitype.Ollama
+	}
+	return apiType
+}

relay/channeltype/url.go

@@ -0,0 +1,43 @@
+package channeltype
+
+var ChannelBaseURLs = []string{
+	"",                              // 0
+	"https://api.openai.com",        // 1
+	"https://oa.api2d.net",          // 2
+	"",                              // 3
+	"https://api.closeai-proxy.xyz", // 4
+	"https://api.openai-sb.com",     // 5
+	"https://api.openaimax.com",     // 6
+	"https://api.ohmygpt.com",       // 7
+	"",                              // 8
+	"https://api.caipacity.com",     // 9
+	"https://api.aiproxy.io",        // 10
+	"https://generativelanguage.googleapis.com", // 11
+	"https://api.api2gpt.com",                   // 12
+	"https://api.aigc2d.com",                    // 13
+	"https://api.anthropic.com",                 // 14
+	"https://aip.baidubce.com",                  // 15
+	"https://open.bigmodel.cn",                  // 16
+	"https://dashscope.aliyuncs.com",            // 17
+	"",                                          // 18
+	"https://ai.360.cn",                         // 19
+	"https://openrouter.ai/api",                 // 20
+	"https://api.aiproxy.io",                    // 21
+	"https://fastgpt.run/api/openapi",           // 22
+	"https://hunyuan.cloud.tencent.com",         // 23
+	"https://generativelanguage.googleapis.com", // 24
+	"https://api.moonshot.cn",                   // 25
+	"https://api.baichuan-ai.com",               // 26
+	"https://api.minimax.chat",                  // 27
+	"https://api.mistral.ai",                    // 28
+	"https://api.groq.com/openai",               // 29
+	"http://localhost:11434",                    // 30
+	"https://api.lingyiwanwu.com",               // 31
+	"https://api.stepfun.com",                   // 32
+}
+
+func init() {
+	if len(ChannelBaseURLs) != Dummy {
+		panic("channel base urls length not match")
+	}
+}