import { createClient } from "@supabase/supabase-js";

const supabaseUrl = process.env.NEXT_PUBLIC_SUPABASE_URL!;
const supabaseKey = process.env.SUPABASE_SERVICE_ROLE_KEY!;
const supabase = createClient(supabaseUrl, supabaseKey);

// Matt's user ID
const MATT_USER_ID = "0a3e400c-3932-48ae-9b65-f3f9c6f26fe9";
const MAX_USER_ID = "9c29cc99-81a1-4e75-8dff-cd7cc5ceb5aa";

interface ParsedTask {
  title: string;
  description?: string;
  assigneeId: string;
  priority: "low" | "medium" | "high";
  dueDate?: string;
  projectId?: string;
}

export function parseTaskInput(input: string): ParsedTask {
  const lower = input.toLowerCase();
  
  // Extract assignee
  let assigneeId = MATT_USER_ID;
  if (lower.includes("assign to max") || lower.includes("for max")) {
    assigneeId = MAX_USER_ID;
  }
  
  // Extract priority
  let priority: "low" | "medium" | "high" = "medium";
  if (lower.includes("urgent") || lower.includes("asap") || lower.includes("high priority")) {
    priority = "high";
  } else if (lower.includes("low priority") || lower.includes("whenever") || lower.includes("eventually")) {
    priority = "low";
  }
  
  // Extract due date phrases
  let dueDate: string | undefined;
  const today = new Date();
  
  if (lower.includes("tomorrow")) {
    const d = new Date(today);
    d.setDate(d.getDate() + 1);
    dueDate = d.toISOString().split("T")[0];
  } else if (lower.includes("next week")) {
    const d = new Date(today);
    d.setDate(d.getDate() + 7);
    dueDate = d.toISOString().split("T")[0];
  } else if (lower.includes("by friday") || lower.includes("this friday")) {
    const d = new Date(today);
    const daysUntilFriday = (5 - d.getDay() + 7) % 7 || 7;
    d.setDate(d.getDate() + daysUntilFriday);
    dueDate = d.toISOString().split("T")[0];
  } else if (lower.includes("by monday") || lower.includes("this monday")) {
    const d = new Date(today);
    const daysUntilMonday = (1 - d.getDay() + 7) % 7 || 7;
    d.setDate(d.getDate() + daysUntilMonday);
    dueDate = d.toISOString().split("T")[0];
  }
  
  // Clean up the title - remove assignee/priority/due date phrases
  let title = input
    .replace(/assign to (max|matt)/gi, "")
    .replace(/for (max|matt)/gi, "")
    .replace(/urgent|asap|high priority|low priority/gi, "")
    .replace(/tomorrow|next week|by friday|this friday|by monday|this monday/gi, "")
    .replace(/\s+/g, " ")
    .trim();
  
  // If it starts with "add task" or similar, remove that
  title = title.replace(/^(add|create|new)\s+(task|todo|item)\s*[:\-]?\s*/i, "");
  
  // Capitalize first letter
  title = title.charAt(0).toUpperCase() + title.slice(1);
  
  return {
    title,
    assigneeId,
    priority,
    dueDate,
  };
}

interface TaskResult {
  id: string;
  title: string;
  [key: string]: unknown;
}

export async function addTaskToGantt(input: string): Promise<{ success: boolean; task?: TaskResult; error?: string }> {
  try {
    const parsed = parseTaskInput(input);
    
    // Get default project (first one) or use a specific project
    const { data: projects } = await supabase
      .from("projects")
      .select("id")
      .order("created_at", { ascending: true })
      .limit(1);
    
    const projectId = projects?.[0]?.id;
    
    if (!projectId) {
      return { success: false, error: "No projects found in gantt board" };
    }
    
    // Create the task
    const { data: task, error } = await supabase
      .from("tasks")
      .insert({
        title: parsed.title,
        description: parsed.description || null,
        status: "todo",
        priority: parsed.priority,
        assignee_id: parsed.assigneeId,
        created_by: MATT_USER_ID,
        project_id: projectId,
        due_date: parsed.dueDate || null,
        start_date: new Date().toISOString().split("T")[0],
        end_date: parsed.dueDate || new Date(Date.now() + 7 * 24 * 60 * 60 * 1000).toISOString().split("T")[0],
      })
      .select()
      .single();
    
    if (error) {
      console.error("Error adding task:", error);
      return { success: false, error: error.message };
    }
    
    return { success: true, task };
  } catch (err: unknown) {
    console.error("Failed to add task:", err);
    const message = err instanceof Error ? err.message : "Unknown error";
    return { success: false, error: message };
  }
}