Bash script to fetch symbol data from Alpha Vantage API, save as JSON, and generate a daily close price graph using gnuplot. Requires curl, jq, gnuplot, and an Alphavantage API key.

alphavantage_daily.sh

#!/bin/bash

# Author: Mahrous Amer
# Date: September 23, 2024

set -euo pipefail

# Constants
BASE_URL='https://www.alphavantage.co'
CONFIG_FILE='config.conf'
LOG_FILE='alphavantage.log'
GRAPH_OUTPUT='graph.png'
RETRY_COUNT=3
RETRY_DELAY=5
DEFAULT_INTERVAL='DAILY'
DEFAULT_OUTPUT_SIZE='full'

# Helpers
log_info() {
    local message="$1"
    echo "$(date '+%Y-%m-%d %H:%M:%S') INFO: ${message}" | tee -a "$LOG_FILE"
}

log_error() {
    local message="$1"
    echo "$(date '+%Y-%m-%d %H:%M:%S') ERROR: ${message}" | tee -a "$LOG_FILE" >&2
}

load_config() {
    if [[ -f "$CONFIG_FILE" ]]; then
        source "$CONFIG_FILE"
    else
        log_error "Configuration file not found: $CONFIG_FILE"
        exit 1
    fi
}

check_dependencies() {
    command -v curl >/dev/null 2>&1 || { log_error "curl is required but not installed."; exit 6; }
    command -v jq >/dev/null 2>&1 || { log_error "jq is required but not installed."; exit 6; }
    command -v gnuplot >/dev/null 2>&1 || { log_error "gnuplot is required but not installed."; exit 6; }
}

validate_args() {
    if [[ -z "${SYMBOL-}" ]]; then
        log_error "Symbol not specified."
        exit 1
    fi
    if [[ -z "${OUTPUT_FILE-}" ]]; then
        OUTPUT_FILE="./${SYMBOL}.json"
    elif [[ -d "$OUTPUT_FILE" ]]; then
        OUTPUT_FILE="${OUTPUT_FILE}/${SYMBOL}.json"
    fi
    if [[ -z "${API_KEY-}" ]]; then
        if [[ -z "${ALPHAVANTAGE_API_KEY-}" ]]; then
            log_error "No API key provided, and 'ALPHAVANTAGE_API_KEY' not in environment."
            exit 2
        else
            API_KEY="${ALPHAVANTAGE_API_KEY}"
        fi
    fi
    INTERVAL="${INTERVAL:-$DEFAULT_INTERVAL}"
    OUTPUT_SIZE="${OUTPUT_SIZE:-$DEFAULT_OUTPUT_SIZE}"
}

fetch_data() {
    local attempt=1
    while [[ $attempt -le $RETRY_COUNT ]]; do
        log_info "Fetching data (attempt $attempt/$RETRY_COUNT) for symbol: '$SYMBOL'"
        if curl -s --fail "${BASE_URL}/query?function=TIME_SERIES_${INTERVAL}&symbol=${SYMBOL}&datatype=json&outputsize=${OUTPUT_SIZE}&apikey=${API_KEY}" -o "$OUTPUT_FILE"; then
            log_info "Data successfully saved to '$OUTPUT_FILE'"
            return 0
        fi
        log_error "Failed to fetch data for symbol: '$SYMBOL' (attempt $attempt/$RETRY_COUNT)"
        ((attempt++))
        [[ $attempt -le $RETRY_COUNT ]] && sleep $RETRY_DELAY
    done
    log_error "Failed to fetch data after $RETRY_COUNT attempts."
    exit 4
}

generate_graph() {
    local json_file="$1"
    local output_image="$2"
    local series_key

    case "$INTERVAL" in
        DAILY) series_key="Time Series (Daily)";;
        WEEKLY) series_key="Weekly Time Series";;
        MONTHLY) series_key="Monthly Time Series";;
        *) log_error "Unsupported interval: $INTERVAL"; exit 7;;
    esac

    # JSON -> CSV for gnuplot
    echo "Date,Close" > data.csv
    jq -r ".[\"$series_key\"] | to_entries[] | [.key, .value[\"4. close\"]] | @csv" "$json_file" >> data.csv

    # Validate CSV data
    if [[ ! -s data.csv ]] || [[ $(wc -l < data.csv) -le 1 ]]; then
        log_error "No valid data found in CSV for graphing."
        exit 5
    fi

    # Generate graph with enhanced styling
    gnuplot <<-EOF
        set datafile separator ","
        set terminal pngcairo size 1000,700 enhanced font "Arial,12"
        set output "$output_image"
        set xdata time
        set timefmt "%Y-%m-%d"
        set format x "%Y-%m-%d"
        set xlabel "Date" font "Arial,14"
        set ylabel "Close Price (USD)" font "Arial,14"
        set title "${SYMBOL} ${INTERVAL} Adjusted Close Price" font "Arial,16"
        set grid
        set key top left
        set style line 1 lc rgb "#0066cc" lw 2
        plot "data.csv" using 1:2 with lines ls 1 title "Close Price"
	EOF

    if [[ $? -ne 0 ]]; then
        log_error "Failed to generate graph."
        exit 5
    fi
    log_info "Graph successfully saved as '$output_image'"
}

# Parse additional arguments
while [[ $# -ge 1 ]]; do
    case "$1" in
        -s|--symbol)
            SYMBOL="$2"; shift 2
            ;;
        -o|--output)
            OUTPUT_FILE="$2"; shift 2
            ;;
        --key)
            API_KEY="$2"; shift 2
            ;;
        -i|--interval)
            INTERVAL="$2"; shift 2
            ;;
        --output-size)
            OUTPUT_SIZE="$2"; shift 2
            ;;
        *)
            log_error "Unexpected argument '$1'"
            exit 3
            ;;
    esac
done

# Main execution
check_dependencies
load_config
validate_args
fetch_data
generate_graph "$OUTPUT_FILE" "$GRAPH_OUTPUT"

# Cleanup
[[ -f data.csv ]] && rm -f data.csv