package categorization_test

import (
	"testing"
	"time"

	"github.com/treytartt/casera-api/internal/models"
	"github.com/treytartt/casera-api/internal/task/categorization"
)

// Helper to create a time pointer
func timePtr(t time.Time) *time.Time {
	return &t
}

func TestCategorizeTask_PriorityOrder(t *testing.T) {
	now := time.Now().UTC()
	yesterday := now.AddDate(0, 0, -1)
	in5Days := now.AddDate(0, 0, 5)
	in60Days := now.AddDate(0, 0, 60)
	inProgressStatus := &models.TaskStatus{Name: "In Progress"}
	daysThreshold := 30

	tests := []struct {
		name     string
		task     *models.Task
		expected categorization.KanbanColumn
	}{
		// Priority 1: Cancelled
		{
			name: "cancelled takes priority over everything",
			task: &models.Task{
				IsCancelled: true,
				NextDueDate: timePtr(yesterday), // Would be overdue
				Status:      inProgressStatus,   // Would be in progress
				Completions: []models.TaskCompletion{{BaseModel: models.BaseModel{ID: 1}}}, // Would be completed if NextDueDate was nil
			},
			expected: categorization.ColumnCancelled,
		},

		// Priority 2: Completed
		{
			name: "completed: NextDueDate nil with completions",
			task: &models.Task{
				IsCancelled: false,
				IsArchived:  false,
				NextDueDate: nil,
				DueDate:     timePtr(yesterday), // Would be overdue if not completed
				Completions: []models.TaskCompletion{{BaseModel: models.BaseModel{ID: 1}}},
			},
			expected: categorization.ColumnCompleted,
		},
		{
			name: "not completed when NextDueDate set (recurring task with completions)",
			task: &models.Task{
				IsCancelled: false,
				IsArchived:  false,
				NextDueDate: timePtr(in5Days),
				Completions: []models.TaskCompletion{{BaseModel: models.BaseModel{ID: 1}}},
			},
			expected: categorization.ColumnDueSoon, // Falls through to due soon
		},

		// Priority 3: In Progress
		{
			name: "in progress takes priority over overdue",
			task: &models.Task{
				IsCancelled: false,
				IsArchived:  false,
				NextDueDate: timePtr(yesterday), // Would be overdue
				Status:      inProgressStatus,
				Completions: []models.TaskCompletion{},
			},
			expected: categorization.ColumnInProgress,
		},

		// Priority 4: Overdue
		{
			name: "overdue: effective date in past",
			task: &models.Task{
				IsCancelled: false,
				IsArchived:  false,
				NextDueDate: timePtr(yesterday),
				Completions: []models.TaskCompletion{},
			},
			expected: categorization.ColumnOverdue,
		},
		{
			name: "overdue: uses DueDate when NextDueDate nil (no completions)",
			task: &models.Task{
				IsCancelled: false,
				IsArchived:  false,
				NextDueDate: nil,
				DueDate:     timePtr(yesterday),
				Completions: []models.TaskCompletion{},
			},
			expected: categorization.ColumnOverdue,
		},

		// Priority 5: Due Soon
		{
			name: "due soon: within threshold",
			task: &models.Task{
				IsCancelled: false,
				IsArchived:  false,
				NextDueDate: timePtr(in5Days),
				Completions: []models.TaskCompletion{},
			},
			expected: categorization.ColumnDueSoon,
		},

		// Priority 6: Upcoming (default)
		{
			name: "upcoming: beyond threshold",
			task: &models.Task{
				IsCancelled: false,
				IsArchived:  false,
				NextDueDate: timePtr(in60Days),
				Completions: []models.TaskCompletion{},
			},
			expected: categorization.ColumnUpcoming,
		},
		{
			name: "upcoming: no due date",
			task: &models.Task{
				IsCancelled: false,
				IsArchived:  false,
				NextDueDate: nil,
				DueDate:     nil,
				Completions: []models.TaskCompletion{},
			},
			expected: categorization.ColumnUpcoming,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result := categorization.CategorizeTask(tt.task, daysThreshold)
			if result != tt.expected {
				t.Errorf("CategorizeTask() = %v, expected %v", result, tt.expected)
			}
		})
	}
}

func TestCategorizeTasksIntoColumns(t *testing.T) {
	now := time.Now().UTC()
	yesterday := now.AddDate(0, 0, -1)
	in5Days := now.AddDate(0, 0, 5)
	in60Days := now.AddDate(0, 0, 60)
	daysThreshold := 30

	tasks := []models.Task{
		{BaseModel: models.BaseModel{ID: 1}, IsCancelled: true},                                                              // Cancelled
		{BaseModel: models.BaseModel{ID: 2}, NextDueDate: nil, Completions: []models.TaskCompletion{{BaseModel: models.BaseModel{ID: 1}}}},                // Completed
		{BaseModel: models.BaseModel{ID: 3}, Status: &models.TaskStatus{Name: "In Progress"}},                                // In Progress
		{BaseModel: models.BaseModel{ID: 4}, NextDueDate: timePtr(yesterday)},                                                // Overdue
		{BaseModel: models.BaseModel{ID: 5}, NextDueDate: timePtr(in5Days)},                                                  // Due Soon
		{BaseModel: models.BaseModel{ID: 6}, NextDueDate: timePtr(in60Days)},                                                 // Upcoming
		{BaseModel: models.BaseModel{ID: 7}},                                                                                 // Upcoming (no due date)
	}

	result := categorization.CategorizeTasksIntoColumns(tasks, daysThreshold)

	// Check each column has the expected tasks
	if len(result[categorization.ColumnCancelled]) != 1 || result[categorization.ColumnCancelled][0].ID != 1 {
		t.Errorf("Expected task 1 in Cancelled column")
	}
	if len(result[categorization.ColumnCompleted]) != 1 || result[categorization.ColumnCompleted][0].ID != 2 {
		t.Errorf("Expected task 2 in Completed column")
	}
	if len(result[categorization.ColumnInProgress]) != 1 || result[categorization.ColumnInProgress][0].ID != 3 {
		t.Errorf("Expected task 3 in InProgress column")
	}
	if len(result[categorization.ColumnOverdue]) != 1 || result[categorization.ColumnOverdue][0].ID != 4 {
		t.Errorf("Expected task 4 in Overdue column")
	}
	if len(result[categorization.ColumnDueSoon]) != 1 || result[categorization.ColumnDueSoon][0].ID != 5 {
		t.Errorf("Expected task 5 in DueSoon column")
	}
	if len(result[categorization.ColumnUpcoming]) != 2 {
		t.Errorf("Expected 2 tasks in Upcoming column, got %d", len(result[categorization.ColumnUpcoming]))
	}
}

func TestDetermineKanbanColumn_ReturnsString(t *testing.T) {
	task := &models.Task{IsCancelled: true}
	result := categorization.DetermineKanbanColumn(task, 30)

	if result != "cancelled_tasks" {
		t.Errorf("DetermineKanbanColumn() = %v, expected %v", result, "cancelled_tasks")
	}
}

func TestKanbanColumnConstants(t *testing.T) {
	// Verify column string values match expected API values
	tests := []struct {
		column   categorization.KanbanColumn
		expected string
	}{
		{categorization.ColumnOverdue, "overdue_tasks"},
		{categorization.ColumnDueSoon, "due_soon_tasks"},
		{categorization.ColumnUpcoming, "upcoming_tasks"},
		{categorization.ColumnInProgress, "in_progress_tasks"},
		{categorization.ColumnCompleted, "completed_tasks"},
		{categorization.ColumnCancelled, "cancelled_tasks"},
	}

	for _, tt := range tests {
		if tt.column.String() != tt.expected {
			t.Errorf("Column %v.String() = %v, expected %v", tt.column, tt.column.String(), tt.expected)
		}
	}
}

func TestNewContext_DefaultThreshold(t *testing.T) {
	task := &models.Task{}

	// Zero threshold should default to 30
	ctx := categorization.NewContext(task, 0)
	if ctx.DaysThreshold != 30 {
		t.Errorf("NewContext with 0 threshold should default to 30, got %d", ctx.DaysThreshold)
	}

	// Negative threshold should default to 30
	ctx = categorization.NewContext(task, -5)
	if ctx.DaysThreshold != 30 {
		t.Errorf("NewContext with negative threshold should default to 30, got %d", ctx.DaysThreshold)
	}

	// Positive threshold should be used
	ctx = categorization.NewContext(task, 45)
	if ctx.DaysThreshold != 45 {
		t.Errorf("NewContext with 45 threshold should be 45, got %d", ctx.DaysThreshold)
	}
}