// Package docs provides API documentation using Swagger/OpenAPI
package docs

import (
	"encoding/json"
	"net/http"
)

// SwaggerInfo holds the API information
var SwaggerInfo = struct {
	Title       string
	Description string
	Version     string
	Host        string
	BasePath    string
	Schemes     []string
}{
	Title:       "OTPM API",
	Description: "API for One-Time Password Manager",
	Version:     "1.0.0",
	Host:        "localhost:8080",
	BasePath:    "/",
	Schemes:     []string{"http", "https"},
}

// SwaggerJSON returns the Swagger JSON
func SwaggerJSON() []byte {
	swagger := map[string]interface{}{
		"swagger": "2.0",
		"info": map[string]interface{}{
			"title":       SwaggerInfo.Title,
			"description": SwaggerInfo.Description,
			"version":     SwaggerInfo.Version,
		},
		"host":     SwaggerInfo.Host,
		"basePath": SwaggerInfo.BasePath,
		"schemes":  SwaggerInfo.Schemes,
		"paths":    getPaths(),
		"definitions": map[string]interface{}{
			"LoginRequest": map[string]interface{}{
				"type": "object",
				"properties": map[string]interface{}{
					"code": map[string]interface{}{
						"type":        "string",
						"description": "WeChat authorization code",
					},
				},
				"required": []string{"code"},
			},
			"LoginResponse": map[string]interface{}{
				"type": "object",
				"properties": map[string]interface{}{
					"token": map[string]interface{}{
						"type":        "string",
						"description": "JWT token",
					},
					"openid": map[string]interface{}{
						"type":        "string",
						"description": "WeChat OpenID",
					},
				},
			},
			"CreateOTPRequest": map[string]interface{}{
				"type": "object",
				"properties": map[string]interface{}{
					"name": map[string]interface{}{
						"type":        "string",
						"description": "OTP name",
					},
					"issuer": map[string]interface{}{
						"type":        "string",
						"description": "OTP issuer",
					},
					"secret": map[string]interface{}{
						"type":        "string",
						"description": "OTP secret",
					},
					"algorithm": map[string]interface{}{
						"type":        "string",
						"description": "OTP algorithm",
						"enum":        []string{"SHA1", "SHA256", "SHA512"},
					},
					"digits": map[string]interface{}{
						"type":        "integer",
						"description": "OTP digits",
						"enum":        []int{6, 8},
					},
					"period": map[string]interface{}{
						"type":        "integer",
						"description": "OTP period in seconds",
						"enum":        []int{30, 60},
					},
				},
				"required": []string{"name", "issuer", "secret", "algorithm", "digits", "period"},
			},
			"OTP": map[string]interface{}{
				"type": "object",
				"properties": map[string]interface{}{
					"id": map[string]interface{}{
						"type":        "string",
						"description": "OTP ID",
					},
					"user_id": map[string]interface{}{
						"type":        "string",
						"description": "User ID",
					},
					"name": map[string]interface{}{
						"type":        "string",
						"description": "OTP name",
					},
					"issuer": map[string]interface{}{
						"type":        "string",
						"description": "OTP issuer",
					},
					"algorithm": map[string]interface{}{
						"type":        "string",
						"description": "OTP algorithm",
					},
					"digits": map[string]interface{}{
						"type":        "integer",
						"description": "OTP digits",
					},
					"period": map[string]interface{}{
						"type":        "integer",
						"description": "OTP period in seconds",
					},
					"created_at": map[string]interface{}{
						"type":        "string",
						"format":      "date-time",
						"description": "Creation time",
					},
					"updated_at": map[string]interface{}{
						"type":        "string",
						"format":      "date-time",
						"description": "Last update time",
					},
				},
			},
			"OTPCodeResponse": map[string]interface{}{
				"type": "object",
				"properties": map[string]interface{}{
					"code": map[string]interface{}{
						"type":        "string",
						"description": "OTP code",
					},
					"expires_in": map[string]interface{}{
						"type":        "integer",
						"description": "Seconds until expiration",
					},
				},
			},
			"VerifyOTPRequest": map[string]interface{}{
				"type": "object",
				"properties": map[string]interface{}{
					"code": map[string]interface{}{
						"type":        "string",
						"description": "OTP code to verify",
					},
				},
				"required": []string{"code"},
			},
			"VerifyOTPResponse": map[string]interface{}{
				"type": "object",
				"properties": map[string]interface{}{
					"valid": map[string]interface{}{
						"type":        "boolean",
						"description": "Whether the code is valid",
					},
				},
			},
			"UpdateOTPRequest": map[string]interface{}{
				"type": "object",
				"properties": map[string]interface{}{
					"name": map[string]interface{}{
						"type":        "string",
						"description": "OTP name",
					},
					"issuer": map[string]interface{}{
						"type":        "string",
						"description": "OTP issuer",
					},
					"algorithm": map[string]interface{}{
						"type":        "string",
						"description": "OTP algorithm",
						"enum":        []string{"SHA1", "SHA256", "SHA512"},
					},
					"digits": map[string]interface{}{
						"type":        "integer",
						"description": "OTP digits",
						"enum":        []int{6, 8},
					},
					"period": map[string]interface{}{
						"type":        "integer",
						"description": "OTP period in seconds",
						"enum":        []int{30, 60},
					},
				},
			},
			"ErrorResponse": map[string]interface{}{
				"type": "object",
				"properties": map[string]interface{}{
					"code": map[string]interface{}{
						"type":        "integer",
						"description": "Error code",
					},
					"message": map[string]interface{}{
						"type":        "string",
						"description": "Error message",
					},
				},
			},
		},
		"securityDefinitions": map[string]interface{}{
			"Bearer": map[string]interface{}{
				"type":        "apiKey",
				"name":        "Authorization",
				"in":          "header",
				"description": "JWT token with Bearer prefix",
			},
		},
	}

	data, _ := json.MarshalIndent(swagger, "", "  ")
	return data
}

// getPaths returns the API paths
func getPaths() map[string]interface{} {
	return map[string]interface{}{
		"/login": map[string]interface{}{
			"post": map[string]interface{}{
				"summary":     "Login with WeChat",
				"description": "Login with WeChat authorization code",
				"tags":        []string{"auth"},
				"parameters": []map[string]interface{}{
					{
						"name":        "body",
						"in":          "body",
						"description": "Login request",
						"required":    true,
						"schema": map[string]interface{}{
							"$ref": "#/definitions/LoginRequest",
						},
					},
				},
				"responses": map[string]interface{}{
					"200": map[string]interface{}{
						"description": "Successful login",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/LoginResponse",
						},
					},
					"400": map[string]interface{}{
						"description": "Invalid request",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
					"500": map[string]interface{}{
						"description": "Internal server error",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
				},
			},
		},
		"/verify-token": map[string]interface{}{
			"post": map[string]interface{}{
				"summary":     "Verify token",
				"description": "Verify JWT token",
				"tags":        []string{"auth"},
				"security": []map[string]interface{}{
					{
						"Bearer": []string{},
					},
				},
				"responses": map[string]interface{}{
					"200": map[string]interface{}{
						"description": "Token is valid",
						"schema": map[string]interface{}{
							"type": "object",
							"properties": map[string]interface{}{
								"valid": map[string]interface{}{
									"type":        "boolean",
									"description": "Whether the token is valid",
								},
							},
						},
					},
					"401": map[string]interface{}{
						"description": "Unauthorized",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
				},
			},
		},
		"/otp": map[string]interface{}{
			"get": map[string]interface{}{
				"summary":     "List OTPs",
				"description": "List all OTPs for the authenticated user",
				"tags":        []string{"otp"},
				"security": []map[string]interface{}{
					{
						"Bearer": []string{},
					},
				},
				"responses": map[string]interface{}{
					"200": map[string]interface{}{
						"description": "List of OTPs",
						"schema": map[string]interface{}{
							"type": "array",
							"items": map[string]interface{}{
								"$ref": "#/definitions/OTP",
							},
						},
					},
					"401": map[string]interface{}{
						"description": "Unauthorized",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
					"500": map[string]interface{}{
						"description": "Internal server error",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
				},
			},
			"post": map[string]interface{}{
				"summary":     "Create OTP",
				"description": "Create a new OTP",
				"tags":        []string{"otp"},
				"security": []map[string]interface{}{
					{
						"Bearer": []string{},
					},
				},
				"parameters": []map[string]interface{}{
					{
						"name":        "body",
						"in":          "body",
						"description": "OTP creation request",
						"required":    true,
						"schema": map[string]interface{}{
							"$ref": "#/definitions/CreateOTPRequest",
						},
					},
				},
				"responses": map[string]interface{}{
					"200": map[string]interface{}{
						"description": "OTP created",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/OTP",
						},
					},
					"400": map[string]interface{}{
						"description": "Invalid request",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
					"401": map[string]interface{}{
						"description": "Unauthorized",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
					"500": map[string]interface{}{
						"description": "Internal server error",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
				},
			},
		},
		"/otp/{id}": map[string]interface{}{
			"put": map[string]interface{}{
				"summary":     "Update OTP",
				"description": "Update an existing OTP",
				"tags":        []string{"otp"},
				"security": []map[string]interface{}{
					{
						"Bearer": []string{},
					},
				},
				"parameters": []map[string]interface{}{
					{
						"name":        "id",
						"in":          "path",
						"description": "OTP ID",
						"required":    true,
						"type":        "string",
					},
					{
						"name":        "body",
						"in":          "body",
						"description": "OTP update request",
						"required":    true,
						"schema": map[string]interface{}{
							"$ref": "#/definitions/UpdateOTPRequest",
						},
					},
				},
				"responses": map[string]interface{}{
					"200": map[string]interface{}{
						"description": "OTP updated",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/OTP",
						},
					},
					"400": map[string]interface{}{
						"description": "Invalid request",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
					"401": map[string]interface{}{
						"description": "Unauthorized",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
					"404": map[string]interface{}{
						"description": "OTP not found",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
					"500": map[string]interface{}{
						"description": "Internal server error",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
				},
			},
			"delete": map[string]interface{}{
				"summary":     "Delete OTP",
				"description": "Delete an existing OTP",
				"tags":        []string{"otp"},
				"security": []map[string]interface{}{
					{
						"Bearer": []string{},
					},
				},
				"parameters": []map[string]interface{}{
					{
						"name":        "id",
						"in":          "path",
						"description": "OTP ID",
						"required":    true,
						"type":        "string",
					},
				},
				"responses": map[string]interface{}{
					"200": map[string]interface{}{
						"description": "OTP deleted",
						"schema": map[string]interface{}{
							"type": "object",
							"properties": map[string]interface{}{
								"message": map[string]interface{}{
									"type":        "string",
									"description": "Success message",
								},
							},
						},
					},
					"401": map[string]interface{}{
						"description": "Unauthorized",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
					"404": map[string]interface{}{
						"description": "OTP not found",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
					"500": map[string]interface{}{
						"description": "Internal server error",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
				},
			},
		},
		"/otp/{id}/code": map[string]interface{}{
			"get": map[string]interface{}{
				"summary":     "Get OTP code",
				"description": "Get the current OTP code",
				"tags":        []string{"otp"},
				"security": []map[string]interface{}{
					{
						"Bearer": []string{},
					},
				},
				"parameters": []map[string]interface{}{
					{
						"name":        "id",
						"in":          "path",
						"description": "OTP ID",
						"required":    true,
						"type":        "string",
					},
				},
				"responses": map[string]interface{}{
					"200": map[string]interface{}{
						"description": "OTP code",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/OTPCodeResponse",
						},
					},
					"401": map[string]interface{}{
						"description": "Unauthorized",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
					"404": map[string]interface{}{
						"description": "OTP not found",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
					"500": map[string]interface{}{
						"description": "Internal server error",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
				},
			},
		},
		"/otp/{id}/verify": map[string]interface{}{
			"post": map[string]interface{}{
				"summary":     "Verify OTP code",
				"description": "Verify an OTP code",
				"tags":        []string{"otp"},
				"security": []map[string]interface{}{
					{
						"Bearer": []string{},
					},
				},
				"parameters": []map[string]interface{}{
					{
						"name":        "id",
						"in":          "path",
						"description": "OTP ID",
						"required":    true,
						"type":        "string",
					},
					{
						"name":        "body",
						"in":          "body",
						"description": "OTP verification request",
						"required":    true,
						"schema": map[string]interface{}{
							"$ref": "#/definitions/VerifyOTPRequest",
						},
					},
				},
				"responses": map[string]interface{}{
					"200": map[string]interface{}{
						"description": "OTP verification result",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/VerifyOTPResponse",
						},
					},
					"400": map[string]interface{}{
						"description": "Invalid request",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
					"401": map[string]interface{}{
						"description": "Unauthorized",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
					"404": map[string]interface{}{
						"description": "OTP not found",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
					"500": map[string]interface{}{
						"description": "Internal server error",
						"schema": map[string]interface{}{
							"$ref": "#/definitions/ErrorResponse",
						},
					},
				},
			},
		},
		"/health": map[string]interface{}{
			"get": map[string]interface{}{
				"summary":     "Health check",
				"description": "Check if the API is healthy",
				"tags":        []string{"system"},
				"responses": map[string]interface{}{
					"200": map[string]interface{}{
						"description": "API is healthy",
						"schema": map[string]interface{}{
							"type": "object",
							"properties": map[string]interface{}{
								"status": map[string]interface{}{
									"type":        "string",
									"description": "Health status",
								},
								"time": map[string]interface{}{
									"type":        "string",
									"format":      "date-time",
									"description": "Current time",
								},
							},
						},
					},
				},
			},
		},
		"/metrics": map[string]interface{}{
			"get": map[string]interface{}{
				"summary":     "Metrics",
				"description": "Get application metrics",
				"tags":        []string{"system"},
				"responses": map[string]interface{}{
					"200": map[string]interface{}{
						"description": "Application metrics",
					},
				},
			},
		},
		"/swagger.json": map[string]interface{}{
			"get": map[string]interface{}{
				"summary":     "Swagger JSON",
				"description": "Get Swagger JSON",
				"tags":        []string{"system"},
				"responses": map[string]interface{}{
					"200": map[string]interface{}{
						"description": "Swagger JSON",
					},
				},
			},
		},
	}
}

// Handler returns an HTTP handler for Swagger JSON
func Handler() http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.Write(SwaggerJSON())
	}
}