#!/usr/bin/env bash
#
# Simple AI agent workflow using bd (Beads issue tracker).
#
# This demonstrates the full lifecycle of an agent managing tasks:
# - Find ready work
# - Claim and execute
# - Discover new issues
# - Link discoveries
# - Complete and move on

set -euo pipefail

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

log_info() {
    echo -e "${BLUE}ℹ ${NC}$1"
}

log_success() {
    echo -e "${GREEN}✓${NC} $1"
}

log_warning() {
    echo -e "${YELLOW}⚠${NC} $1"
}

log_error() {
    echo -e "${RED}✗${NC} $1"
}

AGENT_NAME="${BEADS_AGENT_NAME:-bash-agent-$$}"

# Check if bd is installed
if ! command -v bd &> /dev/null; then
    log_error "bd is not installed"
    echo "Install with: go install github.com/steveyegge/beads/cmd/bd@latest"
    exit 1
fi

# Check if we're in a beads-initialized directory
if ! bd list &> /dev/null; then
    log_error "Not in a beads-initialized directory"
    echo "Run: bd init"
    exit 1
fi

# Find ready work
find_ready_work() {
    bd ready --json --limit 1 2>/dev/null | jq -r '.[0] // empty'
}

# Extract field from JSON
get_field() {
    local json="$1"
    local field="$2"
    echo "$json" | jq -r ".$field"
}

# Claim a task
claim_task() {
    local issue_id="$1"

    log_info "Claiming task: $issue_id"
    bd update "$issue_id" --status in_progress --json > /dev/null

    log_success "Task claimed"
    return 0
}

# Simulate doing work (in real agent, this would call LLM/execute code)
do_work() {
    local issue="$1"
    local issue_id=$(get_field "$issue" "id")
    local title=$(get_field "$issue" "title")
    local priority=$(get_field "$issue" "priority")

    echo ""
    log_info "Working on: $title ($issue_id)"
    echo "  Priority: $priority"

    # Simulate work delay
    sleep 1

    # Simulate discovering new work (50% chance)
    if [[ $((RANDOM % 2)) -eq 0 ]]; then
        log_warning "Discovered issue while working!"

        # Create new issue
        local new_issue=$(bd create "Follow-up: $title" \
            -d "Discovered while working on $issue_id" \
            -p 2 \
            -t task \
            --json)

        local new_id=$(echo "$new_issue" | jq -r '.id')
        log_success "Created issue: $new_id"

        # Link it back to parent
        bd dep add "$new_id" "$issue_id" --type discovered-from
        log_success "Linked $new_id ← discovered-from ← $issue_id"

        return 0 # Discovered new work
    fi

    return 1 # No new work discovered
}

# Complete a task
complete_task() {
    local issue_id="$1"
    local reason="${2:-Completed successfully}"

    log_info "Completing task: $issue_id"
    bd close "$issue_id" --reason "$reason" --json > /dev/null

    log_success "Task completed: $issue_id"
}

# Show statistics
show_stats() {
    echo ""
    echo "═══════════════════════════════════════════════════"
    echo "  Beads Statistics"
    echo "═══════════════════════════════════════════════════"
    bd stats
    echo ""
}

# Main agent loop
run_agent() {
    local max_iterations="${1:-10}"
    local iteration=0

    echo ""
    echo "🚀 Beads Agent starting..."
    echo "   Max iterations: $max_iterations"
    show_stats

    while [[ $iteration -lt $max_iterations ]]; do
        iteration=$((iteration + 1))

        echo ""
        echo "═══════════════════════════════════════════════════"
        echo "  Iteration $iteration/$max_iterations"
        echo "═══════════════════════════════════════════════════"

        # Find ready work
        log_info "Looking for ready work..."
        ready_work=$(find_ready_work)

        if [[ -z "$ready_work" ]]; then
            log_warning "No ready work found. Agent idle."
            break
        fi

        issue_id=$(get_field "$ready_work" "id")

        # Claim it
        if ! claim_task "$issue_id"; then
            log_warning "Failed to claim task, trying next iteration"
            continue
        fi

        # Do the work
        if do_work "$ready_work"; then
            log_info "New work discovered, will process in next iteration"
        fi

        # Complete it
        complete_task "$issue_id"

        # Brief pause between iterations
        sleep 0.5
    done

    echo ""
    log_success "Agent finished after $iteration iterations"
    show_stats
}

# Handle Ctrl-C gracefully
trap 'echo ""; log_warning "Agent interrupted by user"; exit 130' INT

# Run the agent
run_agent "${1:-10}"