#!/usr/bin/env bash

# Next Spec ID Script
# Determines the next available ID number for a spec type

set -o pipefail

SPEC_TYPE="${1:-.}"
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

# Find git repo root for reliable path resolution
# This allows scripts to work when called from any directory in the repo
if git -C "$SCRIPT_DIR" rev-parse --git-dir > /dev/null 2>&1; then
    PROJECT_ROOT="$(git -C "$SCRIPT_DIR" rev-parse --show-toplevel)"
else
    # Fallback to relative path traversal (4 levels up from scripts/)
    # From: project-root/project-basics/skills/spec-author/scripts/
    # To:   project-root/
    PROJECT_ROOT="$(cd "$SCRIPT_DIR/../../../.." && pwd)"
fi

# Specs are always stored in the git repo root under docs/specs/
SPECS_DIR="$PROJECT_ROOT/docs/specs"

# Color codes
RED='\033[0;31m'
GREEN='\033[0;32m'
BLUE='\033[0;34m'
YELLOW='\033[1;33m'
NC='\033[0m'

# Map spec types to their prefixes and folder names
get_spec_info() {
    local type=$1
    case "$type" in
        business-requirement)
            echo "brd:business-requirement"
            ;;
        technical-requirement)
            echo "prd:technical-requirement"
            ;;
        design-document)
            echo "des:design-document"
            ;;
        api-contract)
            echo "api:api-contract"
            ;;
        data-model)
            echo "data:data-model"
            ;;
        component)
            echo "cmp:component"
            ;;
        plan)
            echo "pln:plan"
            ;;
        milestone)
            echo "mls:milestone"
            ;;
        flow-schematic)
            echo "flow:flow-schematic"
            ;;
        deployment-procedure)
            echo "deploy:deployment-procedure"
            ;;
        configuration-schema)
            echo "config:configuration-schema"
            ;;
        *)
            echo ""
            ;;
    esac
}

# Print usage
usage() {
    echo "Usage: next-id.sh <spec-type> [--with-slug <slug>]"
    echo ""
    echo "Determines the next available ID number for a spec type."
    echo ""
    echo "Spec types:"
    echo "  - business-requirement"
    echo "  - technical-requirement"
    echo "  - design-document"
    echo "  - api-contract"
    echo "  - data-model"
    echo "  - component"
    echo "  - plan"
    echo "  - milestone"
    echo "  - flow-schematic"
    echo "  - deployment-procedure"
    echo "  - configuration-schema"
    echo ""
    echo "Options:"
    echo "  --with-slug <slug>    Include slug in output (e.g., brd-001-my-feature)"
    echo "  --quiet               Only output the ID, no formatting"
    echo ""
    echo "Examples:"
    echo "  next-id.sh business-requirement"
    echo "    Output: brd-001"
    echo ""
    echo "  next-id.sh business-requirement --with-slug user-export"
    echo "    Output: brd-001-user-export"
    echo ""
    echo "  next-id.sh api-contract --quiet"
    echo "    Output: api-001"
    exit 1
}

# Parse arguments
SLUG=""
QUIET=false

if [ "$SPEC_TYPE" = "-h" ] || [ "$SPEC_TYPE" = "--help" ] || [ -z "$SPEC_TYPE" ]; then
    usage
fi

shift
while [[ $# -gt 0 ]]; do
    case $1 in
        --with-slug)
            SLUG="$2"
            shift 2
            ;;
        --quiet)
            QUIET=true
            shift
            ;;
        *)
            echo -e "${RED}✗ Unknown option: $1${NC}" >&2
            usage
            ;;
    esac
done

# Get spec info
SPEC_INFO=$(get_spec_info "$SPEC_TYPE")
if [ -z "$SPEC_INFO" ]; then
    echo -e "${RED}✗ Error: Unknown spec type: $SPEC_TYPE${NC}" >&2
    echo "Run 'next-id.sh --help' to see available types" >&2
    exit 1
fi

PREFIX=$(echo "$SPEC_INFO" | cut -d: -f1)
FOLDER=$(echo "$SPEC_INFO" | cut -d: -f2)
SPEC_TYPE_DIR="$SPECS_DIR/$FOLDER"

# Find highest existing ID number
MAX_ID=0

if [ -d "$SPEC_TYPE_DIR" ]; then
    # Look for files matching the pattern: prefix-NNN-*.md
    for file in "$SPEC_TYPE_DIR/$PREFIX"-*.md; do
        if [ -f "$file" ]; then
            # Extract the number part (NNN)
            filename=$(basename "$file" .md)
            # Remove prefix and leading dash
            rest="${filename#$PREFIX-}"
            # Extract just the number (first field before next dash)
            num=$(echo "$rest" | cut -d- -f1)

            # Check if it's a valid number
            if [[ "$num" =~ ^[0-9]+$ ]]; then
                if [ "$num" -gt "$MAX_ID" ]; then
                    MAX_ID=$num
                fi
            fi
        fi
    done
fi

# Calculate next ID
NEXT_NUM=$((MAX_ID + 1))
NEXT_ID=$(printf "%s-%03d" "$PREFIX" "$NEXT_NUM")

# Add slug if provided
if [ -n "$SLUG" ]; then
    FULL_ID="$NEXT_ID-$SLUG"
else
    FULL_ID="$NEXT_ID"
fi

# Output
if [ "$QUIET" = true ]; then
    echo "$FULL_ID"
else
    echo -e "${GREEN}Next available ID for $SPEC_TYPE:${NC}"
    echo -e "${BLUE}$FULL_ID${NC}"
    echo ""
    if [ "$MAX_ID" -gt 0 ]; then
        echo "Last ID: $PREFIX-$(printf "%03d" "$MAX_ID")"
    else
        echo "No existing specs found (this will be the first)"
    fi
fi