<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Services\UtilizationService;
use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;

/**
 * @group Utilization
 *
 * API endpoints for utilization calculations.
 *
 * Utilization measures how effectively team member capacity is being used.
 * It's calculated as (Allocated Hours / Capacity) × 100%.
 *
 * **Color Indicators:**
 * - `gray`: Under-utilized (<70%)
 * - `blue`: Low utilization (70-80%)
 * - `green`: Optimal (80-100%)
 * - `yellow`: High utilization (100-110%)
 * - `red`: Over-allocated (>110%)
 */
class UtilizationController extends Controller
{
    use AuthorizesRequests;
    public function __construct(
        private UtilizationService $utilizationService
    ) {}

    /**
     * Get Running (YTD) Utilization
     *
     * Calculate year-to-date utilization for a specific team member.
     * Running utilization = (Allocated hours Jan-current) / (Capacity Jan-current) × 100%
     *
     * @authenticated
     *
     * @queryParam team_member_id string required UUID of the team member. Example: 550e8400-e29b-41d4-a716-446655440000
     * @queryParam month string required Month in Y-m format (calculates from Jan of this year to this month). Example: 2026-03
     *
     * @response 200 {
     *   "capacity_ytd": 480.0,
     *   "allocated_ytd": 450.0,
     *   "utilization": 93.8,
     *   "indicator": "green",
     *   "months_included": 3
     * }
     * @response 422 {"message":"Validation failed","errors":{"team_member_id":["The selected team member id is invalid."]}}
     */
    public function running(Request $request): JsonResponse
    {
        $this->authorize('viewRunningUtilization', \App\Models\TeamMember::class);

        $request->validate([
            'team_member_id' => 'required|uuid|exists:team_members,id',
            'month' => 'required|date_format:Y-m',
        ]);

        $result = $this->utilizationService->calculateRunningUtilization(
            $request->team_member_id,
            $request->month
        );

        return response()->json($result);
    }

    /**
     * Get Overall (Monthly) Utilization
     *
     * Calculate utilization for a specific team member in a specific month.
     * Overall utilization = (Allocated hours this month) / (Capacity this month) × 100%
     *
     * @authenticated
     *
     * @queryParam team_member_id string required UUID of the team member. Example: 550e8400-e29b-41d4-a716-446655440000
     * @queryParam month string required Month in Y-m format. Example: 2026-02
     *
     * @response 200 {
     *   "capacity": 160.0,
     *   "allocated": 140.0,
     *   "utilization": 87.5,
     *   "indicator": "green"
     * }
     * @response 422 {"message":"Validation failed","errors":{"month":["The month format is invalid."]}}
     */
    public function overall(Request $request): JsonResponse
    {
        $this->authorize('viewOverallUtilization', \App\Models\TeamMember::class);

        $request->validate([
            'team_member_id' => 'required|uuid|exists:team_members,id',
            'month' => 'required|date_format:Y-m',
        ]);

        $result = $this->utilizationService->calculateOverallUtilization(
            $request->team_member_id,
            $request->month
        );

        return response()->json($result);
    }

    /**
     * Get Combined Utilization Data
     *
     * Get both overall (monthly) and running (YTD) utilization for a team member.
     *
     * @authenticated
     *
     * @queryParam team_member_id string required UUID of the team member. Example: 550e8400-e29b-41d4-a716-446655440000
     * @queryParam month string required Month in Y-m format. Example: 2026-03
     *
     * @response 200 {
     *   "overall": {
     *     "capacity": 160.0,
     *     "allocated": 140.0,
     *     "utilization": 87.5,
     *     "indicator": "green"
     *   },
     *   "running": {
     *     "capacity_ytd": 480.0,
     *     "allocated_ytd": 450.0,
     *     "utilization": 93.8,
     *     "indicator": "green",
     *     "months_included": 3
     *   }
     * }
     */
    public function data(Request $request): JsonResponse
    {
        $this->authorize('viewUtilization', \App\Models\TeamMember::class);

        $request->validate([
            'team_member_id' => 'required|uuid|exists:team_members,id',
            'month' => 'required|date_format:Y-m',
        ]);

        $result = $this->utilizationService->getUtilizationData(
            $request->team_member_id,
            $request->month
        );

        return response()->json($result);
    }

    /**
     * Get Team Utilization
     *
     * Calculate average utilization across all active team members for a specific month.
     *
     * @authenticated
     *
     * @queryParam month string required Month in Y-m format. Example: 2026-02
     *
     * @response 200 {
     *   "average_utilization": 85.4,
     *   "average_indicator": "green",
     *   "member_count": 3,
     *   "by_member": {
     *     "550e8400-e29b-41d4-a716-446655440000": {
     *       "capacity": 160.0,
     *       "allocated": 140.0,
     *       "utilization": 87.5,
     *       "indicator": "green"
     *     }
     *   }
     * }
     */
    public function team(Request $request): JsonResponse
    {
        $this->authorize('viewTeamUtilization', \App\Models\TeamMember::class);

        $request->validate([
            'month' => 'required|date_format:Y-m',
        ]);

        $result = $this->utilizationService->calculateTeamUtilization(
            $request->month
        );

        return response()->json($result);
    }

    /**
     * Get Team Running Utilization (YTD)
     *
     * Calculate average year-to-date utilization across all active team members.
     *
     * @authenticated
     *
     * @queryParam month string required Month in Y-m format. Example: 2026-03
     *
     * @response 200 {
     *   "average_utilization": 88.2,
     *   "average_indicator": "green",
     *   "member_count": 3,
     *   "by_member": {}
     * }
     */
    public function teamRunning(Request $request): JsonResponse
    {
        $this->authorize('viewTeamRunningUtilization', \App\Models\TeamMember::class);

        $request->validate([
            'month' => 'required|date_format:Y-m',
        ]);

        $result = $this->utilizationService->calculateTeamRunningUtilization(
            $request->month
        );

        return response()->json($result);
    }

    /**
     * Get Utilization Trend
     *
     * Get utilization data for a team member over a range of months.
     *
     * @authenticated
     *
     * @queryParam team_member_id string required UUID of the team member. Example: 550e8400-e29b-41d4-a716-446655440000
     * @queryParam start_month string required Start month in Y-m format. Example: 2026-01
     * @queryParam end_month string required End month in Y-m format (must be >= start_month). Example: 2026-06
     *
     * @response 200 [
     *   {
     *     "month": "2026-01",
     *     "utilization": 75.0,
     *     "indicator": "blue",
     *     "capacity": 176.0,
     *     "allocated": 132.0
     *   },
     *   {
     *     "month": "2026-02",
     *     "utilization": 87.5,
     *     "indicator": "green",
     *     "capacity": 160.0,
     *     "allocated": 140.0
     *   }
     * ]
     */
    public function trend(Request $request): JsonResponse
    {
        $this->authorize('viewUtilizationTrend', \App\Models\TeamMember::class);

        $request->validate([
            'team_member_id' => 'required|uuid|exists:team_members,id',
            'start_month' => 'required|date_format:Y-m',
            'end_month' => 'required|date_format:Y-m|after_or_equal:start_month',
        ]);

        $result = $this->utilizationService->getUtilizationTrend(
            $request->team_member_id,
            $request->start_month,
            $request->end_month
        );

        return response()->json($result);
    }
}