Laravel 5 Eloquent - Create nested JSON object (3 levels deep) from complex query

I'm working with an existing Database which has the following structure:

projects
-----------------
| id | name     |
-----------------
| 1  | building |
| 2  | pavement |
-----------------

accounts
---------------
| id | name   |
---------------
| 8  | income |
| 9  | oucome |
---------------

policies
----------------------------------
| id | project_id | canceled     |
----------------------------------
| 14 | 1          | 1            |
| 15 | 1          | 0            |
| 16 | 2          | 0            |
----------------------------------

detailed_policies
---------------------------------------------------------------
| id | policy_id | account_id | project_id | amount  | date 
---------------------------------------------------------------
| 1  | 15        | 8          | 1          | 80.0    | 20151212
| 1  | 15        | 8          | 1          | 500.5   | 20160102
| 2  | 15        | 8          | 1          | 30000.0 | 20160102
| 2  | 16        | 9          | 2          | 9500.0  | 20160622
---------------------------------------------------------------

• A project has many policies, detailed_policies.
• A policy has many detailed_policies.
• An account has many detailed_policies.

So far the models look like this:

class Project extends \Eloquent
{
    public function policies()
    {
        return $this->hasMany('Models\Policies');
    }
    public function detailed_policies()
    {
        return $this->hasMany('Models\DetailedPolicies');
    }
}

class Account extends \Eloquent
{
    public function detailed_policies()
    {
        return $this->hasMany('Models\DetailedPolicies');
    }
}

class Policies extends \Eloquent 
{
    public function project()
    {
        return $this->belongsTo('Models\Project');
    }
    public function detailed_policies()
    {
        return $this->hasMany('Models\DetailedPolicies');
    }
}

class DetailedPolicies extends \Eloquent 
{
    public function project()
    {
        return $this->belongsTo('Models\Project');
    }
    public function account()
    {
        return $this->belongsTo('Models\Account');
    }
    public function policies()
    {
        return $this->belongsTo('Models\Policies');
    }
}

I'm new with eloquent and I'm trying to write a lazy-loaded eloquent query that will get me:

• Accounts affected. (level1)
• Projects involved. (level2)
• Policies & Detailed policies (level 3).
• Filtered by a range of date.

Query should return a nested JSON array. I'm thinking something like this:

{
    "Projects" : [
    {
        "projects" : [
        {
            "project_id" : "1",
            "name":"building site",
            "accounts" : [
                {
                    "account":"income",
                    "policies" : [
                        {
                          "policy_id" : "11",
                          "desc" : "..."
                        },
                        {
                          "policy_id" : "12",
                          "desc" : "..."
                        }
                    ],
                    "detailed_policies" : [
                        {
                          "detailed_policy_id" : "1",
                          "amount" : "1800.00"
                        },
                        {
                          "detailed_policy_id" : "2",
                          "amount" : "500.00"
                        }
                    ]
                },
                {
                    "account":"outcome",
                    "policies" : [
                        {
                          "policy_id" : "11",
                          "desc" : "..."
                        },
                        {
                          "policy_id" : "12",
                          "desc" : "..."
                        }
                    ],
                    "detailed_policies" : [
                        {
                          "detailed_policy_id" : "1",
                          "amount" : "1800.00"
                        },
                        {
                          "detailed_policy_id" : "2",
                          "amount" : "500.00"
                        }
                    ]
                }
            ]
        }, ...

I'm aware that the DB may need modifications such as a pivot table for Accounts and Projects.

Can anyone suggest an efficient way to approach this?

Note: Purpose of this is to consume the returned object in an AngularJS app that will display a summary by accounts or by projects.

Thanks in advance.

via Chebli Mohamed