package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"sort"
	"strings"

	_ "bsm/full/module/base/ads/pb"
	_ "bsm/full/module/base/cloud/pb"
	_ "bsm/full/module/base/cms/pb"
	_ "bsm/full/module/base/feedback/pb"
	_ "bsm/full/module/base/initial/pb"
	_ "bsm/full/module/base/passport/pb"
	_ "bsm/full/module/base/sender/pb"
	_ "bsm/full/module/ec/address/pb"
	_ "bsm/full/module/ec/mall/pb"
	_ "bsm/full/module/ec/market/pb"
	_ "bsm/full/module/ec/order/pb"
	_ "bsm/full/module/finance/wallet/pb"
	_ "bsm/full/module/social/feed/pb"
	_ "bsm/full/module/social/group/pb"
	_ "bsm/full/module/social/relation/pb"
	"google.golang.org/protobuf/reflect/protoreflect"
	"google.golang.org/protobuf/reflect/protoregistry"
)

type moduleInfo struct {
	Order       int
	Name        string
	Package     protoreflect.FullName
	Description string
}

var modules = []moduleInfo{
	{1, "ads", "ads", "广告获取与投放内容读取。"},
	{2, "cloud", "cloud", "云端相册、书签、网盘、笔记、私密数据、分享和空间管理。"},
	{3, "cms", "cms", "站点、页面、文章、栏目和标签内容管理。"},
	{4, "feedback", "feedback", "用户反馈提交与查询。"},
	{5, "initial", "initial", "客户端初始化、基础数据和版本更新检查。"},
	{6, "passport", "passport", "账号注册、登录、验证、找回密码和账户资料管理。"},
	{7, "sender", "sender", "邮件、短信发送及验证码校验。"},
	{8, "address", "address", "用户地址库管理。"},
	{9, "mall", "mall", "商城广告、类目、运费、公告、商品、员工和店铺管理。"},
	{10, "market", "market", "市场代理商、供应商及经营数据管理。"},
	{11, "order", "order", "购物车、优惠券、订单汇总及商家订单管理。"},
	{12, "wallet", "wallet", "钱包、支付方式、支付宝与微信支付。"},
	{13, "feed", "feed", "动态发布、标签、时间线和动态设置。"},
	{14, "group", "group", "群组及成员管理。"},
	{15, "relation", "relation", "关注、好友和关系匹配。"},
}

func main() {
	root, err := filepath.Abs(filepath.Join("..", ".."))
	must(err)
	outDir := filepath.Join(root, "wiki", "api")
	must(os.MkdirAll(outDir, 0o755))

	for _, module := range modules {
		services := servicesFor(module.Package)
		content := renderModule(module, services)
		name := fmt.Sprintf("%02d-%s.md", module.Order, module.Name)
		must(os.WriteFile(filepath.Join(outDir, name), content, 0o644))
	}
}

func servicesFor(pkg protoreflect.FullName) []protoreflect.ServiceDescriptor {
	var services []protoreflect.ServiceDescriptor
	protoregistry.GlobalFiles.RangeFiles(func(file protoreflect.FileDescriptor) bool {
		if file.Package() != pkg {
			return true
		}
		for i := 0; i < file.Services().Len(); i++ {
			services = append(services, file.Services().Get(i))
		}
		return true
	})
	sort.Slice(services, func(i, j int) bool { return services[i].FullName() < services[j].FullName() })
	return services
}

func renderModule(module moduleInfo, services []protoreflect.ServiceDescriptor) []byte {
	var out bytes.Buffer
	fmt.Fprintf(&out, "# %s API\n\n%s\n\n", strings.ToUpper(module.Name), module.Description)
	out.WriteString("> 本文档由 protobuf descriptor 生成。字段名采用 protobuf JSON 名称；64 位整数在 JSON 中应按字符串处理。\n\n")
	out.WriteString("## 接入方式\n\n")
	fmt.Fprintf(&out, "- 动态 HTTP：`POST /rpc/%s/{Service}/{Method}`\n", module.Package)
	fmt.Fprintf(&out, "- 原生 gRPC：`/%s.{Service}/{Method}`\n", module.Package)
	fmt.Fprintf(&out, "- grpc-gateway：`POST /%s.{Service}/{Method}`\n", module.Package)
	out.WriteString("- 鉴权：需要登录的接口通过 `Authorization: Bearer <token>` 传递凭证。\n")
	out.WriteString("- 动态 HTTP 成功或失败均返回 HTTP 200，业务状态见 `code`、`message`、`details`。\n\n")

	out.WriteString("## 服务概览\n\n")
	out.WriteString("| 服务 | 方法数 | 说明 |\n|---|---:|---|\n")
	for _, service := range services {
		fmt.Fprintf(&out, "| `%s` | %d | %s 服务 |\n", service.Name(), service.Methods().Len(), service.Name())
	}

	schemas := map[protoreflect.FullName]protoreflect.MessageDescriptor{}
	enums := map[protoreflect.FullName]protoreflect.EnumDescriptor{}
	for _, service := range services {
		fmt.Fprintf(&out, "\n## %s\n\n", service.Name())
		out.WriteString("| 方法 | 动态 HTTP 路径 | 请求 | 响应 | 类型 |\n|---|---|---|---|---|\n")
		for i := 0; i < service.Methods().Len(); i++ {
			method := service.Methods().Get(i)
			kind := "Unary"
			if method.IsStreamingClient() || method.IsStreamingServer() {
				kind = "Streaming（动态 HTTP 暂不支持）"
			}
			fmt.Fprintf(&out, "| `%s` | `POST /rpc/%s/%s/%s` | [`%s`](#%s) | [`%s`](#%s) | %s |\n",
				method.Name(), module.Package, service.Name(), method.Name(),
				method.Input().FullName(), anchor(method.Input().FullName()), method.Output().FullName(), anchor(method.Output().FullName()), kind)
			collectMessage(method.Input(), schemas, enums)
			collectMessage(method.Output(), schemas, enums)
		}

		for i := 0; i < service.Methods().Len(); i++ {
			method := service.Methods().Get(i)
			fmt.Fprintf(&out, "\n### %s.%s\n\n", service.Name(), method.Name())
			fmt.Fprintf(&out, "- 动态 HTTP：`POST /rpc/%s/%s/%s`\n", module.Package, service.Name(), method.Name())
			fmt.Fprintf(&out, "- gRPC：`/%s/%s`\n", service.FullName(), method.Name())
			fmt.Fprintf(&out, "- 白名单键：`%s.%s`\n", service.FullName(), method.Name())
			out.WriteString("- 请求示例：\n\n```json\n")
			out.Write(exampleJSON(method.Input()))
			out.WriteString("\n```\n")
		}
	}

	messageNames := sortedMessageNames(schemas)
	if len(messageNames) > 0 {
		out.WriteString("\n## 消息结构\n")
	}
	for _, name := range messageNames {
		renderMessage(&out, schemas[name], enums)
	}

	enumNames := make([]string, 0, len(enums))
	for name := range enums {
		enumNames = append(enumNames, string(name))
	}
	sort.Strings(enumNames)
	if len(enumNames) > 0 {
		out.WriteString("\n## 枚举\n")
	}
	for _, rawName := range enumNames {
		renderEnum(&out, enums[protoreflect.FullName(rawName)])
	}
	return out.Bytes()
}

func collectMessage(message protoreflect.MessageDescriptor, messages map[protoreflect.FullName]protoreflect.MessageDescriptor, enums map[protoreflect.FullName]protoreflect.EnumDescriptor) {
	if _, exists := messages[message.FullName()]; exists {
		return
	}
	messages[message.FullName()] = message
	for i := 0; i < message.Fields().Len(); i++ {
		field := message.Fields().Get(i)
		if field.Message() != nil {
			collectMessage(field.Message(), messages, enums)
		}
		if field.Enum() != nil {
			enums[field.Enum().FullName()] = field.Enum()
		}
	}
}

func renderMessage(out *bytes.Buffer, message protoreflect.MessageDescriptor, enums map[protoreflect.FullName]protoreflect.EnumDescriptor) {
	fmt.Fprintf(out, "\n### %s\n\n", message.FullName())
	if message.Fields().Len() == 0 {
		out.WriteString("空消息：请求时发送 `{}`。\n")
		return
	}
	out.WriteString("| JSON 字段 | 类型 | 规则 |\n|---|---|---|\n")
	for i := 0; i < message.Fields().Len(); i++ {
		field := message.Fields().Get(i)
		rule := "可选"
		if field.Cardinality() == protoreflect.Repeated {
			rule = "数组"
		}
		if field.IsMap() {
			rule = "对象映射"
		}
		if field.ContainingOneof() != nil && !field.ContainingOneof().IsSynthetic() {
			rule = "oneof: " + string(field.ContainingOneof().Name())
		}
		fmt.Fprintf(out, "| `%s` | `%s` | %s |\n", field.JSONName(), fieldType(field), rule)
		if field.Enum() != nil {
			enums[field.Enum().FullName()] = field.Enum()
		}
	}
}

func renderEnum(out *bytes.Buffer, enum protoreflect.EnumDescriptor) {
	fmt.Fprintf(out, "\n### %s\n\n", enum.FullName())
	out.WriteString("| 名称 | 数值 |\n|---|---:|\n")
	for i := 0; i < enum.Values().Len(); i++ {
		value := enum.Values().Get(i)
		fmt.Fprintf(out, "| `%s` | %d |\n", value.Name(), value.Number())
	}
}

func fieldType(field protoreflect.FieldDescriptor) string {
	var value string
	switch field.Kind() {
	case protoreflect.MessageKind, protoreflect.GroupKind:
		value = string(field.Message().FullName())
	case protoreflect.EnumKind:
		value = string(field.Enum().FullName())
	default:
		value = field.Kind().String()
	}
	if field.IsMap() {
		value = "map<" + fieldType(field.MapKey()) + ", " + fieldType(field.MapValue()) + ">"
	} else if field.Cardinality() == protoreflect.Repeated {
		value = "[]" + value
	}
	return value
}

func exampleJSON(message protoreflect.MessageDescriptor) []byte {
	value := exampleMessage(message, map[protoreflect.FullName]bool{}, 0)
	data, err := json.MarshalIndent(value, "", "  ")
	must(err)
	return data
}

func exampleMessage(message protoreflect.MessageDescriptor, visiting map[protoreflect.FullName]bool, depth int) map[string]any {
	if depth > 2 || visiting[message.FullName()] {
		return map[string]any{}
	}
	visiting[message.FullName()] = true
	defer delete(visiting, message.FullName())
	result := map[string]any{}
	seenOneof := map[protoreflect.Name]bool{}
	for i := 0; i < message.Fields().Len(); i++ {
		field := message.Fields().Get(i)
		if oneof := field.ContainingOneof(); oneof != nil && !oneof.IsSynthetic() {
			if seenOneof[oneof.Name()] {
				continue
			}
			seenOneof[oneof.Name()] = true
		}
		value := exampleField(field, visiting, depth)
		if field.Cardinality() == protoreflect.Repeated && !field.IsMap() {
			value = []any{value}
		}
		if field.IsMap() {
			value = map[string]any{"key": exampleField(field.MapValue(), visiting, depth)}
		}
		result[field.JSONName()] = value
	}
	return result
}

func exampleField(field protoreflect.FieldDescriptor, visiting map[protoreflect.FullName]bool, depth int) any {
	switch field.Kind() {
	case protoreflect.BoolKind:
		return false
	case protoreflect.StringKind:
		return "string"
	case protoreflect.BytesKind:
		return "BASE64"
	case protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind,
		protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
		return "0"
	case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind,
		protoreflect.Uint32Kind, protoreflect.Fixed32Kind, protoreflect.FloatKind, protoreflect.DoubleKind:
		return 0
	case protoreflect.EnumKind:
		if field.Enum().Values().Len() > 0 {
			return string(field.Enum().Values().Get(0).Name())
		}
		return 0
	case protoreflect.MessageKind, protoreflect.GroupKind:
		return exampleMessage(field.Message(), visiting, depth+1)
	default:
		return nil
	}
}

func sortedMessageNames(messages map[protoreflect.FullName]protoreflect.MessageDescriptor) []protoreflect.FullName {
	names := make([]protoreflect.FullName, 0, len(messages))
	for name := range messages {
		names = append(names, name)
	}
	sort.Slice(names, func(i, j int) bool { return names[i] < names[j] })
	return names
}

func anchor(name protoreflect.FullName) string {
	return strings.ToLower(strings.ReplaceAll(string(name), ".", ""))
}

func must(err error) {
	if err != nil {
		panic(err)
	}
}