package tools

import (
	"context"
	"encoding/json"
	"fmt"

	"github.com/vektah/gqlparser/v2"
	"github.com/vektah/gqlparser/v2/ast"
	"gogs.dmsc.dev/arp/graph"
)

// Query executes a GraphQL query
func Query(ctx context.Context, resolver *graph.Resolver, schema *ast.Schema, args map[string]interface{}) (CallToolResult, error) {
	queryStr, ok := args["query"].(string)
	if !ok {
		return CallToolResult{
			Content: []ContentBlock{
				{Type: "text", Text: "Missing required 'query' parameter"},
			},
			IsError: true,
		}, nil
	}

	// Parse variables
	variables := make(map[string]interface{})
	if v, ok := args["variables"].(map[string]interface{}); ok {
		variables = v
	}

	// Parse the query
	queryDoc, err := gqlparser.LoadQuery(schema, queryStr)
	if err != nil {
		return CallToolResult{
			Content: []ContentBlock{
				{Type: "text", Text: fmt.Sprintf("Query parse error: %v", err)},
			},
			IsError: true,
		}, nil
	}

	// Execute each operation
	var results []interface{}
	for _, op := range queryDoc.Operations {
		if op.Operation != ast.Query {
			continue
		}

		result, errMsg := executeQuery(ctx, resolver, schema, queryDoc, op, variables)
		if errMsg != "" {
			return CallToolResult{
				Content: []ContentBlock{
					{Type: "text", Text: errMsg},
				},
				IsError: true,
			}, nil
		}
		results = append(results, result)
	}

	// Format response
	var responseText string
	if len(results) == 1 {
		bytes, _ := json.MarshalIndent(results[0], "", "  ")
		responseText = string(bytes)
	} else {
		bytes, _ := json.MarshalIndent(results, "", "  ")
		responseText = string(bytes)
	}

	return CallToolResult{
		Content: []ContentBlock{
			{Type: "text", Text: responseText},
		},
	}, nil
}

func executeQuery(ctx context.Context, resolver *graph.Resolver, schema *ast.Schema, doc *ast.QueryDocument, op *ast.OperationDefinition, variables map[string]interface{}) (map[string]interface{}, string) {
	result := make(map[string]interface{})

	for _, sel := range op.SelectionSet {
		field, ok := sel.(*ast.Field)
		if !ok {
			continue
		}

		value, errMsg := resolveQueryField(ctx, resolver, schema, field, variables)
		if errMsg != "" {
			return nil, errMsg
		}
		result[field.Alias] = value
	}

	return result, ""
}

func resolveQueryField(ctx context.Context, resolver *graph.Resolver, schema *ast.Schema, field *ast.Field, variables map[string]interface{}) (interface{}, string) {
	// Get field arguments
	args := make(map[string]interface{})
	for _, arg := range field.Arguments {
		value, err := arg.Value.Value(variables)
		if err != nil {
			return nil, fmt.Sprintf("failed to evaluate argument %s: %v", arg.Name, err)
		}
		args[arg.Name] = value
	}

	// Resolve based on field name
	switch field.Name {
	case "users":
		users, err := resolver.Query().Users(ctx)
		if err != nil {
			return nil, err.Error()
		}
		return users, ""

	case "user":
		id, _ := args["id"].(string)
		user, err := resolver.Query().User(ctx, id)
		if err != nil {
			return nil, err.Error()
		}
		return user, ""

	case "notes":
		notes, err := resolver.Query().Notes(ctx)
		if err != nil {
			return nil, err.Error()
		}
		return notes, ""

	case "note":
		id, _ := args["id"].(string)
		note, err := resolver.Query().Note(ctx, id)
		if err != nil {
			return nil, err.Error()
		}
		return note, ""

	case "roles":
		roles, err := resolver.Query().Roles(ctx)
		if err != nil {
			return nil, err.Error()
		}
		return roles, ""

	case "role":
		id, _ := args["id"].(string)
		role, err := resolver.Query().Role(ctx, id)
		if err != nil {
			return nil, err.Error()
		}
		return role, ""

	case "permissions":
		perms, err := resolver.Query().Permissions(ctx)
		if err != nil {
			return nil, err.Error()
		}
		return perms, ""

	case "permission":
		id, _ := args["id"].(string)
		perm, err := resolver.Query().Permission(ctx, id)
		if err != nil {
			return nil, err.Error()
		}
		return perm, ""

	case "services":
		services, err := resolver.Query().Services(ctx)
		if err != nil {
			return nil, err.Error()
		}
		return services, ""

	case "service":
		id, _ := args["id"].(string)
		service, err := resolver.Query().Service(ctx, id)
		if err != nil {
			return nil, err.Error()
		}
		return service, ""

	case "tasks":
		tasks, err := resolver.Query().Tasks(ctx)
		if err != nil {
			return nil, err.Error()
		}
		return tasks, ""

	case "task":
		id, _ := args["id"].(string)
		task, err := resolver.Query().Task(ctx, id)
		if err != nil {
			return nil, err.Error()
		}
		return task, ""

	case "taskStatuses":
		statuses, err := resolver.Query().TaskStatuses(ctx)
		if err != nil {
			return nil, err.Error()
		}
		return statuses, ""

	case "taskStatus":
		id, _ := args["id"].(string)
		status, err := resolver.Query().TaskStatus(ctx, id)
		if err != nil {
			return nil, err.Error()
		}
		return status, ""

	case "messages":
		messages, err := resolver.Query().Messages(ctx)
		if err != nil {
			return nil, err.Error()
		}
		return messages, ""

	case "message":
		id, _ := args["id"].(string)
		message, err := resolver.Query().Message(ctx, id)
		if err != nil {
			return nil, err.Error()
		}
		return message, ""

	default:
		return nil, fmt.Sprintf("unknown field: %s", field.Name)
	}
}