#!/bin/bash

# AI-Grep: Semantic search tool
# Beautiful implementation using composable functions

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
source "$SCRIPT_DIR/ai-common"

show_usage() {
    cat << 'EOF'
Usage: ai-grep [OPTIONS] PATTERN [FILE...]
Semantic search based on meaning rather than exact string matching.

Options:
  -v    Select non-matching lines (semantic inverse)
  -n    Show line numbers
  -c    Show only count of matching lines
  -h    Show this help message
EOF
}

build_grep_prompt() {
    local pattern="$1"
    local invert_match="$2"
    local show_numbers="$3"
    local count_only="$4"
    
    local match_instruction
    if [[ "$invert_match" == "true" ]]; then
        match_instruction="Find lines that do NOT semantically match this pattern. Return only those non-matching lines, one per line."
    else
        match_instruction="Find lines that semantically match this pattern. Return only those matching lines, one per line."
    fi
    
    local output_instruction
    if [[ "$count_only" == "true" ]]; then
        output_instruction="Output only a single number - the count of matching lines."
    elif [[ "$show_numbers" == "true" ]]; then
        output_instruction="Prefix each line with its line number followed by a colon (format: 'N:line')."
    else
        output_instruction="Output only the lines themselves, no prefixes or formatting."
    fi
    
    cat << EOF
You are a semantic grep tool. Analyze the following text and find lines that semantically match the pattern '$pattern'.

CRITICAL: Output ONLY the requested lines or count. Do not include explanations, introductory text, or analysis.

$match_instruction

$output_instruction
EOF
}

process_grep_response() {
    local response="$1"
    local count_only="$2"
    
    if [[ "$count_only" == "true" ]]; then
        local count
        if ! count=$(process_count_response "$response"); then
            return $?
        fi
        
        echo "$count"
        if [[ "$count" -gt 0 ]]; then
            return 0
        else
            return "$EXIT_NO_MATCH"
        fi
    else
        process_filtered_response "$response"
    fi
}

validate_and_setup() {
    local pattern="$1"
    shift
    local files=("$@")
    
    ensure_dependencies
    ensure_argument_provided "Pattern" "$pattern" show_usage
    
    [[ ${#files[@]} -gt 0 ]] && ensure_files_exist "${files[@]}"
}

main() {
    local invert_match="false"
    local show_numbers="false"
    local count_only="false"
    local pattern=""
    local files=()
    
    # Parse options
    while getopts "vnch" opt; do
        case $opt in
            v) invert_match="true" ;;
            n) show_numbers="true" ;;
            c) count_only="true" ;;
            h) handle_help_option show_usage ;;
            \?) handle_invalid_option "$OPTARG" ;;
        esac
    done
    
    shift $((OPTIND-1))
    pattern="$1"
    shift
    files=("$@")
    
    # Early validation with immediate exit on failure
    validate_and_setup "$pattern" "${files[@]}"
    
    # Process input with early exit
    local input
    input=$(process_input_sources "${files[@]}") || exit "$EXIT_NO_MATCH"
    
    # Execute LLM request with early exit
    local prompt response
    prompt=$(build_grep_prompt "$pattern" "$invert_match" "$show_numbers" "$count_only")
    response=$(execute_llm_request "$prompt" "$input") || handle_llm_error $?
    
    # Process response with early exit
    local result
    result=$(process_grep_response "$response" "$count_only") || exit $?
    
    echo "$result"
}

main "$@"