import { createSignal, onMount, For, Show } from 'solid-js';
import { Card } from '@/components/ui/Card';
import { Button } from '@/components/ui/Button';
import { 
  IconCalendar, 
  IconTrendingUp, 
  IconBook,
  IconFolder,
  IconExternalLink,
  IconGitBranch,
  IconGitMerge,
  IconGitPullRequest,
  IconGitCommit
} from '@tabler/icons-solidjs';
import { isDemoMode } from '@/lib/demo-mode';

interface ActivityData {
  date: string;
  count: number;
  level: number; // 0-5 intensity level
}

interface ActivityEvent {
  type: 'push' | 'pull_request' | 'merge' | 'issue' | 'bookmark' | 'project' | 'learning' | 'note' | 'commit';
  title: string;
  date: string;
  link?: string;
  repo?: string;
  action?: string;
}

interface GitHubActivityProps {
  title?: string;
  showStats?: boolean;
  showContributionGraph?: boolean;
  showRecentActivity?: boolean;
  compact?: boolean;
  period?: 'year' | 'month' | 'week';
  customEvents?: ActivityEvent[];
  hideHeader?: boolean;
  fullWidth?: boolean;
  externalData?: {
    contributions: Array<{
      date: string;
      count: number;
      level: number;
    }>;
    total_count: number;
  };
}

export const GitHubActivity = (props: GitHubActivityProps) => {
  const [activities, setActivities] = createSignal<ActivityData[]>([]);
  const [recentEvents, setRecentEvents] = createSignal<ActivityEvent[]>([]);
  const [selectedPeriod, setSelectedPeriod] = createSignal<'year' | 'month' | 'week'>(props.period || 'year');
  
  const [stats, setStats] = createSignal({
    totalContributions: 0,
    currentStreak: 0,
    longestStreak: 0
  });

  const setEmptyData = () => {
    setActivities([]);
    setRecentEvents(props.customEvents || []);
    setStats({
      totalContributions: 0,
      currentStreak: 0,
      longestStreak: 0
    });
  };

  const setDemoData = () => {
    // Generate mock contribution data for the last year
    const mockActivities: ActivityData[] = [];
    const today = new Date();
    
    for (let i = 364; i >= 0; i--) {
      const date = new Date(today);
      date.setDate(date.getDate() - i);
      
      // Random activity level (0-5), with higher probability of 0-2
      const random = Math.random();
      let level = 0;
      if (random > 0.7) level = 1;
      if (random > 0.85) level = 2;
      if (random > 0.93) level = 3;
      if (random > 0.97) level = 4;
      if (random > 0.99) level = 5;
      
      mockActivities.push({
        date: date.toISOString().split('T')[0],
        count: level,
        level: level
      });
    }
    
    // Calculate stats
    const totalContributions = mockActivities.reduce((sum, day) => sum + day.count, 0);
    const currentStreak = Math.floor(Math.random() * 15) + 5; // 5-20 days
    const longestStreak = Math.floor(Math.random() * 30) + 20; // 20-50 days
    
    // Mock recent events
    const mockEvents: ActivityEvent[] = [
      {
        type: 'push',
        title: 'Pushed 3 commits to trackeep/frontend',
        date: '2 hours ago',
        repo: 'trackeep',
        action: 'pushed'
      },
      {
        type: 'pull_request',
        title: 'Opened PR: Add dark mode support',
        date: '1 day ago',
        repo: 'trackeep',
        action: 'opened PR'
      },
      {
        type: 'merge',
        title: 'Merged PR: Fix responsive design issues',
        date: '2 days ago',
        repo: 'trackeep',
        action: 'merged'
      },
      {
        type: 'commit',
        title: 'Commit: Update API documentation',
        date: '3 days ago',
        repo: 'trackeep',
        action: 'committed'
      },
      {
        type: 'push',
        title: 'Pushed 5 commits to trackeep/backend',
        date: '1 week ago',
        repo: 'trackeep',
        action: 'pushed'
      }
    ];
    
    setActivities(mockActivities);
    setRecentEvents(mockEvents);
    setStats({
      totalContributions,
      currentStreak,
      longestStreak
    });
  };

  onMount(() => {
    // Listen for external GitHub activity data
    const handleGitHubActivityData = (event: CustomEvent) => {
      const data = event.detail as {
        contributions: Array<{
          date: string;
          count: number;
          level: number;
        }>;
        total_count: number;
      };
      
      if (data.contributions && data.contributions.length > 0) {
        const activityData = data.contributions.map(c => ({
          date: c.date,
          count: c.count,
          level: c.level
        }));
        setActivities(activityData);
        setStats(prev => ({
          ...prev,
          totalContributions: data.total_count
        }));
      }
    };

    window.addEventListener('githubActivityData', handleGitHubActivityData as EventListener);

    if (props.externalData) {
      // Use provided external data
      const activityData = props.externalData.contributions.map(c => ({
        date: c.date,
        count: c.count,
        level: c.level
      }));
      setActivities(activityData);
      setStats(prev => ({
        ...prev,
        totalContributions: props.externalData!.total_count
      }));
    } else if (isDemoMode()) {
      setDemoData();
    } else {
      setEmptyData();
    }

    return () => {
      window.removeEventListener('githubActivityData', handleGitHubActivityData as EventListener);
    };
  });

  const getMonthLabels = () => {
    const months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'];
    const today = new Date();
    const labels = [];
    
    for (let i = 11; i >= 0; i--) {
      const date = new Date(today);
      date.setMonth(date.getMonth() - i);
      labels.push(months[date.getMonth()]);
    }
    
    return labels;
  };


  const getActivityColor = (level: number) => {
    // Use project-themed colors instead of Christmas tree colors
    // Based on the primary theme color with varying intensities
    const colors = [
      'hsl(var(--muted) / 0.3)', // Level 0 - no activity (very light muted)
      'hsl(var(--primary) / 0.2)', // Level 1 - very light primary
      'hsl(var(--primary) / 0.4)', // Level 2 - light primary  
      'hsl(var(--primary) / 0.6)', // Level 3 - medium primary
      'hsl(var(--primary) / 0.8)', // Level 4 - strong primary
      'hsl(var(--primary))'  // Level 5 - full primary
    ];
    return colors[level] || colors[0];
  };

  const formatContributionCount = (count: number) => {
    if (count >= 1000) {
      return `${(count / 1000).toFixed(1)}k`;
    }
    return count.toString();
  };

  const getEventIcon = (type: ActivityEvent['type']) => {
    switch (type) {
      case 'push':
      case 'commit':
        return <IconGitBranch class="size-4 text-primary" />;
      case 'pull_request':
        return <IconGitPullRequest class="size-4 text-primary" />;
      case 'merge':
        return <IconGitMerge class="size-4 text-primary" />;
      case 'issue':
        return <IconBook class="size-4 text-primary" />;
      case 'bookmark':
        return <IconBook class="size-4 text-primary" />;
      case 'project':
        return <IconFolder class="size-4 text-primary" />;
      case 'learning':
        return <IconTrendingUp class="size-4 text-primary" />;
      case 'note':
        return <IconBook class="size-4 text-primary" />;
      default:
        return <IconGitCommit class="size-4 text-primary" />;
    }
  };

  return (
    <div class="space-y-6">
      {/* Header (can be hidden by parent) */}
      {!props.hideHeader && (
        <div class="flex justify-between items-center">
          <div>
            <h2 class="text-2xl font-bold text-foreground">
              {props.title || 'Activity Overview'}
            </h2>
            <p class="text-muted-foreground mt-1">
              Track your contributions and activity over time
            </p>
          </div>
          <div class="flex gap-2">
            {(['year', 'month', 'week'] as const).map((period) => (
              <Button
                variant={selectedPeriod() === period ? 'default' : 'outline'}
                onClick={() => setSelectedPeriod(period)}
                size="sm"
              >
                {period.charAt(0).toUpperCase() + period.slice(1)}
              </Button>
            ))}
          </div>
        </div>
      )}

      {/* Stats Overview */}
      <Show when={props.showStats !== false}>
        <div class={`grid ${props.compact ? 'grid-cols-1' : 'grid-cols-1 md:grid-cols-3'} gap-4`}>
          <Card class="p-6">
            <div class="flex items-center gap-3">
              <div class="bg-primary/10 flex items-center justify-center p-3 rounded-lg">
                <IconTrendingUp class="size-6 text-primary" />
              </div>
              <div>
                <p class="text-2xl font-bold text-foreground">
                  {formatContributionCount(stats().totalContributions)}
                </p>
                <p class="text-sm text-muted-foreground">Total contributions</p>
              </div>
            </div>
          </Card>

          <Card class="p-6">
            <div class="flex items-center gap-3">
              <div class="bg-primary/10 flex items-center justify-center p-3 rounded-lg">
                <IconCalendar class="size-6 text-primary" />
              </div>
              <div>
                <p class="text-2xl font-bold text-foreground">{stats().currentStreak}</p>
                <p class="text-sm text-muted-foreground">Current streak</p>
              </div>
            </div>
          </Card>

          <Card class="p-6">
            <div class="flex items-center gap-3">
              <div class="bg-primary/10 flex items-center justify-center p-3 rounded-lg">
                <IconCalendar class="size-6 text-primary" />
              </div>
              <div>
                <p class="text-2xl font-bold text-foreground">{stats().longestStreak}</p>
                <p class="text-sm text-muted-foreground">Longest streak</p>
              </div>
            </div>
          </Card>
        </div>
      </Show>

      {/* Contribution Graph */}
      <Show when={props.showContributionGraph !== false}>
        <Card class="p-6">
          <div class="mb-4">
            <h3 class="text-lg font-semibold text-foreground mb-2">
              {formatContributionCount(stats().totalContributions)} contributions in the last year
            </h3>
          </div>

          <Show
            when={activities().length > 0}
            fallback={
              <div class="h-44 border border-dashed border-border rounded-lg flex items-center justify-center">
                <p class="text-sm text-muted-foreground">No GitHub contribution data yet.</p>
              </div>
            }
          >
            {/* Month labels - Show all months with responsive spacing */}
            <div class="flex justify-between mb-3 px-6 sm:px-8 text-xs sm:text-sm font-medium overflow-x-auto">
              <div class="flex gap-2 sm:gap-3 min-w-max">
                {getMonthLabels().map((month) => (
                  <span class="text-foreground/80 hover:text-foreground transition-colors cursor-default whitespace-nowrap">
                    {month}
                  </span>
                ))}
              </div>
            </div>

            {/* Contribution grid - Responsive and prevents overflow */}
            <div class="overflow-hidden w-full">
              <div class="flex gap-1 min-w-0">
                {/* Day labels */}
                <div class="flex flex-col gap-1 pr-2 flex-shrink-0">
                  {['Mon', 'Wed', 'Fri'].map((day) => (
                    <div class="h-3 flex items-center justify-end">
                      <span class="text-xs text-foreground/70 hover:text-foreground transition-colors cursor-default font-medium">
                        {day}
                      </span>
                    </div>
                  ))}
                </div>

                {/* Weekly columns - Responsive with proper overflow handling */}
                <div class="flex gap-1 overflow-x-auto overflow-y-hidden min-w-0 pb-2">
                  {Array.from({ length: 53 }, (_, weekIndex) => (
                    <div class="flex flex-col gap-1 flex-shrink-0">
                      {Array.from({ length: 7 }, (_, dayIndex) => {
                        const activityIndex = weekIndex * 7 + dayIndex;
                        const activity = activities()[activityIndex];

                        if (!activity) {
                          return (
                            <div
                              class="w-2.5 h-2.5 sm:w-3 sm:h-3 rounded-sm flex-shrink-0 transition-all"
                              style={`background-color: ${getActivityColor(0)}`}
                            ></div>
                          );
                        }

                        return (
                          <div
                            class="w-2.5 h-2.5 sm:w-3 sm:h-3 rounded-sm hover:ring-1 hover:ring-primary cursor-pointer transition-all flex-shrink-0 hover:scale-110"
                            style={`background-color: ${getActivityColor(activity.level)}`}
                            title={`${activity.date}: ${activity.count} contributions`}
                          ></div>
                        );
                      })}
                    </div>
                  ))}
                </div>
              </div>
            </div>

            {/* Legend */}
            <div class="flex items-center justify-between mt-4">
              <span class="text-xs text-muted-foreground">Less</span>
              <div class="flex gap-1">
                {[0, 1, 2, 3, 4].map((level) => (
                  <div
                    class="w-2.5 h-2.5 sm:w-3 sm:h-3 rounded-sm"
                    style={`background-color: ${getActivityColor(level)}`}
                  ></div>
                ))}
              </div>
              <span class="text-xs text-muted-foreground">More</span>
            </div>
          </Show>
        </Card>
      </Show>

      {/* Recent Activity */}
      <Show when={props.showRecentActivity !== false}>
        <Card class="p-6">
          <div class="flex items-center justify-between mb-4">
            <h3 class="text-lg font-semibold text-foreground">Recent Activity</h3>
            <div class="flex items-center gap-2 text-sm text-muted-foreground">
              <div class="w-2 h-2 rounded-full bg-green-500"></div>
              <span>Active</span>
            </div>
          </div>
          <Show
            when={recentEvents().length > 0}
            fallback={<p class="text-sm text-muted-foreground">No GitHub events yet.</p>}
          >
            <div class="space-y-3 max-h-64 overflow-y-auto">
              <For each={recentEvents()}>
                {(event) => (
                  <div class="flex items-center justify-between p-3 bg-card rounded-lg border hover:bg-muted/50 transition-colors">
                    <div class="flex items-center gap-3">
                      <div class="bg-primary/10 p-2 rounded-lg">
                        {getEventIcon(event.type)}
                      </div>
                      <div class="flex-1">
                        <p class="text-sm text-foreground font-medium">{event.title}</p>
                        <div class="flex items-center gap-2 text-xs text-muted-foreground mt-1">
                          <span>{event.date}</span>
                          {event.repo && (
                            <>
                              <span>•</span>
                              <span class="text-primary">{event.repo}</span>
                            </>
                          )}
                          {event.action && (
                            <>
                              <span>•</span>
                              <span>{event.action}</span>
                            </>
                          )}
                        </div>
                      </div>
                    </div>
                    {event.link && (
                      <Button 
                        variant="ghost" 
                        size="sm"
                        onClick={() => {
                          if (event.link) {
                            window.location.href = event.link;
                          }
                        }}
                        class="hover:bg-primary/10 transition-colors"
                      >
                        <IconExternalLink class="size-4" />
                      </Button>
                    )}
                  </div>
                )}
              </For>
            </div>
          </Show>
        </Card>
      </Show>
    </div>
  );
};