// Copyright 2025 Google LLC
//
// 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.

package cloudsqlwaitforoperation

import (
	"context"
	"fmt"
	"time"

	yaml "github.com/goccy/go-yaml"
	"github.com/googleapis/genai-toolbox/internal/embeddingmodels"
	"github.com/googleapis/genai-toolbox/internal/sources"
	"github.com/googleapis/genai-toolbox/internal/tools"
	"github.com/googleapis/genai-toolbox/internal/util/parameters"
	"google.golang.org/api/sqladmin/v1"
)

const kind string = "cloud-sql-wait-for-operation"

var cloudSQLConnectionMessageTemplate = `Your Cloud SQL resource is ready.

To connect, please configure your environment. The method depends on how you are running the toolbox:

**If running locally via stdio:**
Update the MCP server configuration with the following environment variables:
` + "```json" + `
{
  "mcpServers": {
    "cloud-sql-{{.DBType}}": {
      "command": "./PATH/TO/toolbox",
      "args": ["--prebuilt","cloud-sql-{{.DBType}}","--stdio"],
      "env": {
          "CLOUD_SQL_{{.DBTypeUpper}}_PROJECT": "{{.Project}}",
          "CLOUD_SQL_{{.DBTypeUpper}}_REGION": "{{.Region}}",
          "CLOUD_SQL_{{.DBTypeUpper}}_INSTANCE": "{{.Instance}}",
          "CLOUD_SQL_{{.DBTypeUpper}}_DATABASE": "{{.Database}}",
          "CLOUD_SQL_{{.DBTypeUpper}}_USER": "<your-user>",
          "CLOUD_SQL_{{.DBTypeUpper}}_PASSWORD": "<your-password>"
      }
    }
  }
}
` + "```" + `

**If running remotely:**
For remote deployments, you will need to set the following environment variables in your deployment configuration:
` + "```" + `
CLOUD_SQL_{{.DBTypeUpper}}_PROJECT={{.Project}}
CLOUD_SQL_{{.DBTypeUpper}}_REGION={{.Region}}
CLOUD_SQL_{{.DBTypeUpper}}_INSTANCE={{.Instance}}
CLOUD_SQL_{{.DBTypeUpper}}_DATABASE={{.Database}}
CLOUD_SQL_{{.DBTypeUpper}}_USER=<your-user>
CLOUD_SQL_{{.DBTypeUpper}}_PASSWORD=<your-password>
` + "```" + `

Please refer to the official documentation for guidance on deploying the toolbox:
- Deploying the Toolbox: https://googleapis.github.io/genai-toolbox/how-to/deploy_toolbox/
- Deploying on GKE: https://googleapis.github.io/genai-toolbox/how-to/deploy_gke/
`

func init() {
	if !tools.Register(kind, newConfig) {
		panic(fmt.Sprintf("tool kind %q already registered", kind))
	}
}

func newConfig(ctx context.Context, name string, decoder *yaml.Decoder) (tools.ToolConfig, error) {
	actual := Config{Name: name}
	if err := decoder.DecodeContext(ctx, &actual); err != nil {
		return nil, err
	}
	return actual, nil
}

type compatibleSource interface {
	GetDefaultProject() string
	GetService(context.Context, string) (*sqladmin.Service, error)
	UseClientAuthorization() bool
	GetWaitForOperations(context.Context, *sqladmin.Service, string, string, string, time.Duration) (any, error)
}

// Config defines the configuration for the wait-for-operation tool.
type Config struct {
	Name         string   `yaml:"name" validate:"required"`
	Kind         string   `yaml:"kind" validate:"required"`
	Source       string   `yaml:"source" validate:"required"`
	Description  string   `yaml:"description"`
	AuthRequired []string `yaml:"authRequired"`
	BaseURL      string   `yaml:"baseURL"`

	// Polling configuration
	Delay      string  `yaml:"delay"`
	MaxDelay   string  `yaml:"maxDelay"`
	Multiplier float64 `yaml:"multiplier"`
	MaxRetries int     `yaml:"maxRetries"`
}

// validate interface
var _ tools.ToolConfig = Config{}

// ToolConfigKind returns the kind of the tool.
func (cfg Config) ToolConfigKind() string {
	return kind
}

// Initialize initializes the tool from the configuration.
func (cfg Config) Initialize(srcs map[string]sources.Source) (tools.Tool, error) {
	rawS, ok := srcs[cfg.Source]
	if !ok {
		return nil, fmt.Errorf("no source named %q configured", cfg.Source)
	}

	s, ok := rawS.(compatibleSource)
	if !ok {
		return nil, fmt.Errorf("invalid source for %q tool: source kind must be `cloud-sql-admin`", kind)
	}

	project := s.GetDefaultProject()
	var projectParam parameters.Parameter
	if project != "" {
		projectParam = parameters.NewStringParameterWithDefault("project", project, "The GCP project ID. This is pre-configured; do not ask for it unless the user explicitly provides a different one.")
	} else {
		projectParam = parameters.NewStringParameter("project", "The project ID")
	}

	allParameters := parameters.Parameters{
		projectParam,
		parameters.NewStringParameter("operation", "The operation ID"),
	}
	paramManifest := allParameters.Manifest()

	description := cfg.Description
	if description == "" {
		description = "This will poll on operations API until the operation is done. For checking operation status we need projectId and operationId. Once instance is created give follow up steps on how to use the variables to bring data plane MCP server up in local and remote setup."
	}
	mcpManifest := tools.GetMcpManifest(cfg.Name, description, cfg.AuthRequired, allParameters, nil)

	var delay time.Duration
	if cfg.Delay == "" {
		delay = 3 * time.Second
	} else {
		var err error
		delay, err = time.ParseDuration(cfg.Delay)
		if err != nil {
			return nil, fmt.Errorf("invalid value for delay: %w", err)
		}
	}

	var maxDelay time.Duration
	if cfg.MaxDelay == "" {
		maxDelay = 4 * time.Minute
	} else {
		var err error
		maxDelay, err = time.ParseDuration(cfg.MaxDelay)
		if err != nil {
			return nil, fmt.Errorf("invalid value for maxDelay: %w", err)
		}
	}

	multiplier := cfg.Multiplier
	if multiplier == 0 {
		multiplier = 2.0
	}

	maxRetries := cfg.MaxRetries
	if maxRetries == 0 {
		maxRetries = 10
	}

	return Tool{
		Config:      cfg,
		AllParams:   allParameters,
		manifest:    tools.Manifest{Description: cfg.Description, Parameters: paramManifest, AuthRequired: cfg.AuthRequired},
		mcpManifest: mcpManifest,
		Delay:       delay,
		MaxDelay:    maxDelay,
		Multiplier:  multiplier,
		MaxRetries:  maxRetries,
	}, nil
}

// Tool represents the wait-for-operation tool.
type Tool struct {
	Config
	AllParams   parameters.Parameters `yaml:"allParams"`
	manifest    tools.Manifest
	mcpManifest tools.McpManifest

	// Polling configuration
	Delay      time.Duration
	MaxDelay   time.Duration
	Multiplier float64
	MaxRetries int
}

func (t Tool) ToConfig() tools.ToolConfig {
	return t.Config
}

// Invoke executes the tool's logic.
func (t Tool) Invoke(ctx context.Context, resourceMgr tools.SourceProvider, params parameters.ParamValues, accessToken tools.AccessToken) (any, error) {
	source, err := tools.GetCompatibleSource[compatibleSource](resourceMgr, t.Source, t.Name, t.Kind)
	if err != nil {
		return nil, err
	}

	paramsMap := params.AsMap()

	project, ok := paramsMap["project"].(string)
	if !ok {
		return nil, fmt.Errorf("missing 'project' parameter")
	}
	operationID, ok := paramsMap["operation"].(string)
	if !ok {
		return nil, fmt.Errorf("missing 'operation' parameter")
	}

	ctx, cancel := context.WithTimeout(ctx, 30*time.Minute)
	defer cancel()

	service, err := source.GetService(ctx, string(accessToken))
	if err != nil {
		return nil, err
	}

	delay := t.Delay
	maxDelay := t.MaxDelay
	multiplier := t.Multiplier
	maxRetries := t.MaxRetries
	retries := 0

	for retries < maxRetries {
		select {
		case <-ctx.Done():
			return nil, fmt.Errorf("timed out waiting for operation: %w", ctx.Err())
		default:
		}

		op, err := source.GetWaitForOperations(ctx, service, project, operationID, cloudSQLConnectionMessageTemplate, delay)
		if err != nil {
			return nil, err
		} else if op != nil {
			return op, nil
		}

		time.Sleep(delay)
		delay = time.Duration(float64(delay) * multiplier)
		if delay > maxDelay {
			delay = maxDelay
		}
		retries++
	}
	return nil, fmt.Errorf("exceeded max retries waiting for operation")
}

// ParseParams parses the parameters for the tool.
func (t Tool) ParseParams(data map[string]any, claims map[string]map[string]any) (parameters.ParamValues, error) {
	return parameters.ParseParams(t.AllParams, data, claims)
}

func (t Tool) EmbedParams(ctx context.Context, paramValues parameters.ParamValues, embeddingModelsMap map[string]embeddingmodels.EmbeddingModel) (parameters.ParamValues, error) {
	return parameters.EmbedParams(ctx, t.AllParams, paramValues, embeddingModelsMap, nil)
}

// Manifest returns the tool's manifest.
func (t Tool) Manifest() tools.Manifest {
	return t.manifest
}

// McpManifest returns the tool's MCP manifest.
func (t Tool) McpManifest() tools.McpManifest {
	return t.mcpManifest
}

// Authorized checks if the tool is authorized.
func (t Tool) Authorized(verifiedAuthServices []string) bool {
	return true
}

func (t Tool) RequiresClientAuthorization(resourceMgr tools.SourceProvider) (bool, error) {
	source, err := tools.GetCompatibleSource[compatibleSource](resourceMgr, t.Source, t.Name, t.Kind)
	if err != nil {
		return false, err
	}
	return source.UseClientAuthorization(), nil
}

func (t Tool) GetAuthTokenHeaderName(resourceMgr tools.SourceProvider) (string, error) {
	return "Authorization", nil
}