// Copyright 2026 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 cloudloggingadminquerylogs

import (
	"context"
	"fmt"
	"time"

	"github.com/goccy/go-yaml"
	"github.com/googleapis/genai-toolbox/internal/embeddingmodels"
	"github.com/googleapis/genai-toolbox/internal/sources"
	cla "github.com/googleapis/genai-toolbox/internal/sources/cloudloggingadmin"
	"github.com/googleapis/genai-toolbox/internal/tools"
	"github.com/googleapis/genai-toolbox/internal/util/parameters"
)

const (
	resourceType string = "cloud-logging-admin-query-logs"

	defaultLimit               int = 200
	defaultStartTimeOffsetDays int = 30
)

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

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 {
	UseClientAuthorization() bool
	QueryLogs(ctx context.Context, params cla.QueryLogsParams, accessToken string) ([]map[string]any, error)
}

type Config struct {
	Name         string   `yaml:"name" validate:"required"`
	Type         string   `yaml:"type" validate:"required"`
	Source       string   `yaml:"source" validate:"required"`
	Description  string   `yaml:"description" validate:"required"`
	AuthRequired []string `yaml:"authRequired"`
}

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

func (cfg Config) ToolConfigType() string {
	return resourceType
}

func (cfg Config) Initialize(srcs map[string]sources.Source) (tools.Tool, error) {
	startTimeDescription := fmt.Sprintf("Start time in RFC3339 format (e.g., 2025-12-09T00:00:00Z). Defaults to %d days ago.", defaultStartTimeOffsetDays)
	limitDescription := fmt.Sprintf("Maximum number of log entries to return. Default: %d.", defaultLimit)
	params := parameters.Parameters{
		parameters.NewStringParameterWithRequired(
			"filter",
			"Cloud Logging filter query. Common fields: resource.type, resource.labels.*, logName, severity, textPayload, jsonPayload.*, protoPayload.*, labels.*, httpRequest.*. Operators: =, !=, <, <=, >, >=, :, =~, AND, OR, NOT.",
			false,
		),
		parameters.NewBooleanParameterWithRequired("newestFirst", "Set to true for newest logs first. Defaults to oldest first.", false),
		parameters.NewStringParameterWithRequired("startTime", startTimeDescription, false),
		parameters.NewStringParameterWithRequired("endTime", "End time in RFC3339 format (e.g., 2025-12-09T23:59:59Z). Defaults to now.", false),
		parameters.NewBooleanParameterWithRequired("verbose", "Include additional fields (insertId, trace, spanId, httpRequest, labels, operation, sourceLocation). Defaults to false.", false),
		parameters.NewIntParameterWithRequired("limit", limitDescription, false),
	}

	mcpManifest := tools.GetMcpManifest(cfg.Name, cfg.Description, cfg.AuthRequired, params, nil)

	t := Tool{
		Config:      cfg,
		manifest:    tools.Manifest{Description: cfg.Description, Parameters: params.Manifest(), AuthRequired: cfg.AuthRequired},
		mcpManifest: mcpManifest,
		Parameters:  params,
	}
	return t, nil
}

// validate interface
var _ tools.Tool = Tool{}

type Tool struct {
	Config
	Parameters  parameters.Parameters `yaml:"parameters"`
	manifest    tools.Manifest
	mcpManifest tools.McpManifest
}

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.Type)
	if err != nil {
		return nil, err
	}

	// Parse parameters
	limit := defaultLimit
	paramsMap := params.AsMap()
	newestFirst, _ := paramsMap["newestFirst"].(bool)

	// Check and set limit
	if val, ok := paramsMap["limit"].(int); ok && val > 0 {
		limit = val
	} else if ok && val < 0 {
		return nil, fmt.Errorf("limit must be greater than or equal to 1")
	}

	// Check for verbosity of output
	verbose, _ := paramsMap["verbose"].(bool)

	// Build filter
	var filter string
	if f, ok := paramsMap["filter"].(string); ok {
		if len(f) == 0 {
			return nil, fmt.Errorf("filter cannot be empty if provided")
		}
		filter = f
	}

	// Parse start time
	var startTime string
	if val, ok := paramsMap["startTime"].(string); ok && val != "" {
		if _, err := time.Parse(time.RFC3339, val); err != nil {
			return nil, fmt.Errorf("startTime must be in RFC3339 format (e.g., 2025-12-09T00:00:00Z): %w", err)
		}
		startTime = val
	} else {
		startTime = time.Now().AddDate(0, 0, -defaultStartTimeOffsetDays).Format(time.RFC3339)
	}

	// Parse end time
	var endTime string
	if val, ok := paramsMap["endTime"].(string); ok && val != "" {
		if _, err := time.Parse(time.RFC3339, val); err != nil {
			return nil, fmt.Errorf("endTime must be in RFC3339 format (e.g., 2025-12-09T23:59:59Z): %w", err)
		}
		endTime = val
	}

	tokenString := ""
	if source.UseClientAuthorization() {
		tokenString, err = accessToken.ParseBearerToken()
		if err != nil {
			return nil, fmt.Errorf("failed to parse access token: %w", err)
		}
	}

	queryParams := cla.QueryLogsParams{
		Filter:      filter,
		NewestFirst: newestFirst,
		StartTime:   startTime,
		EndTime:     endTime,
		Verbose:     verbose,
		Limit:       limit,
	}

	return source.QueryLogs(ctx, queryParams, tokenString)
}

func (t Tool) ParseParams(data map[string]any, claimsMap map[string]map[string]any) (parameters.ParamValues, error) {
	return parameters.ParseParams(t.Parameters, data, claimsMap)
}

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

func (t Tool) Manifest() tools.Manifest {
	return t.manifest
}

func (t Tool) McpManifest() tools.McpManifest {
	return t.mcpManifest
}

func (t Tool) Authorized(verifiedAuthServices []string) bool {
	return tools.IsAuthorized(t.AuthRequired, verifiedAuthServices)
}

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

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

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

func (t Tool) GetParameters() parameters.Parameters {
	return t.Parameters
}