#!/bin/bash
# -----------------------------------------------------------------------------------------------
# --------------------------------- Bandwidth Monitor ------------------------------------------
# -----------------------------------------------------------------------------------------------
# Logs rsync transfer history and generates weekly summary reports.
# Designed for minimal flash drive impact — one bounded write per rsync run.
#
# Two modes:
#   --log-transfer "profile" duration status  — called by rsync.sh after each sync
#                                               appends one line, trims old entries
#   --report (or no args)                     — generates summary from log
#
# Log format — one line per transfer, version-proof, never needs rsync output parsing:
#   YYYY-MM-DD|HH:MM|profile|duration_seconds|status
#
# Log file stays bounded to BANDWIDTH_LOG_RETENTION days — old entries trimmed on every write.
# Minimal flash drive impact: one append + one trim per rsync run.
#
# All configuration in Master.conf under Bandwidth Monitor section.
# -----------------------------------------------------------------------------------------------

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

source "$SCRIPT_DIR/../Master.conf"
source "$SCRIPT_DIR/../common.sh"

parse_args "$@"

# -----------------------------------------------------------------------------------------------
# Parse mode from PARSED_ARGS
# -----------------------------------------------------------------------------------------------
LOG_TRANSFER_MODE=false
TRANSFER_PROFILE=""
TRANSFER_DURATION=0
TRANSFER_STATUS="success"

for arg in "${PARSED_ARGS[@]}"; do
    case "$arg" in
        --log-transfer) LOG_TRANSFER_MODE=true ;;
        --report)       LOG_TRANSFER_MODE=false ;;
        *)
            if [[ "$LOG_TRANSFER_MODE" == true ]]; then
                if [[ -z "$TRANSFER_PROFILE" ]]; then
                    TRANSFER_PROFILE="$arg"
                elif [[ "$TRANSFER_DURATION" -eq 0 ]]; then
                    TRANSFER_DURATION="$arg"
                else
                    TRANSFER_STATUS="$arg"
                fi
            fi
            ;;
    esac
done

# Ensure log directory and file exist
mkdir -p "$(dirname "$BANDWIDTH_LOG")"
touch "$BANDWIDTH_LOG" 2>/dev/null || {
    error "Cannot write to bandwidth log: $BANDWIDTH_LOG"
    exit 1
}

# -----------------------------------------------------------------------------------------------
# LOG TRANSFER MODE
# Called by rsync.sh after each sync — appends one line and trims old entries.
# Usage: bandwidth_monitor.sh --log-transfer "profile" duration_seconds status
# -----------------------------------------------------------------------------------------------
if [[ "$LOG_TRANSFER_MODE" == true ]]; then
    [[ -z "$TRANSFER_PROFILE" ]] && error "No profile specified for --log-transfer" && exit 1

    TODAY=$(date '+%Y-%m-%d')
    NOW=$(date '+%H:%M')
    DURATION_FMT=$(format_duration "$TRANSFER_DURATION")

    # Append entry
    echo "${TODAY}|${NOW}|${TRANSFER_PROFILE}|${TRANSFER_DURATION}|${TRANSFER_STATUS}" >> "$BANDWIDTH_LOG"
    log "$ICON_BANDWIDTH Logged: $TRANSFER_PROFILE — ${DURATION_FMT} — $TRANSFER_STATUS"

    # Trim entries older than retention period — keeps file bounded
    CUTOFF=$(date -d "${BANDWIDTH_LOG_RETENTION} days ago" '+%Y-%m-%d')
    TEMP_FILE="${BANDWIDTH_LOG}.tmp"
    awk -F'|' -v cutoff="$CUTOFF" '$1 >= cutoff' "$BANDWIDTH_LOG" > "$TEMP_FILE" && \
        mv "$TEMP_FILE" "$BANDWIDTH_LOG"
    log "$ICON_BANDWIDTH Log trimmed — retaining entries from $CUTOFF onwards"
    exit 0
fi

# -----------------------------------------------------------------------------------------------
# REPORT MODE — generate summary from log
# -----------------------------------------------------------------------------------------------
echo ""
echo "━━━ $ICON_BANDWIDTH Bandwidth Report — $(date '+%Y-%m-%d %H:%M:%S') ━━━"
echo ""

if [[ ! -s "$BANDWIDTH_LOG" ]]; then
    warn "No bandwidth data yet — log is empty"
    warn "Data accumulates as rsync jobs complete"
    exit 0
fi

START=$(date +%s)

# Date range
OLDEST=$(awk -F'|' 'NR==1{print $1}' "$BANDWIDTH_LOG")
NEWEST=$(awk -F'|' 'END{print $1}' "$BANDWIDTH_LOG")
ENTRY_COUNT=$(wc -l < "$BANDWIDTH_LOG")
SUCCESS_COUNT=$(awk -F'|' '$5=="success"' "$BANDWIDTH_LOG" | wc -l)
FAILED_COUNT=$(awk -F'|' '$5=="failed"' "$BANDWIDTH_LOG" | wc -l)

info "Log covers: $OLDEST → $NEWEST ($ENTRY_COUNT runs)"
echo ""

# ── Per-profile breakdown ────────────────────────────────────────────────────────────────────
echo "━━━ $ICON_BANDWIDTH Per-Profile Summary ━━━"
awk -F'|' '{
    runs[$3]++
    duration[$3] += $4
    if ($5 == "failed") fails[$3]++
}
END {
    for (profile in runs) {
        avg = (runs[profile] > 0) ? duration[profile] / runs[profile] : 0
        mins = int(avg / 60)
        secs = int(avg % 60)
        fail_count = (profile in fails) ? fails[profile] : 0
        printf "  %-20s %3d runs  avg %dm%ds  failed: %d\n", \
            profile, runs[profile], mins, secs, fail_count
    }
}' "$BANDWIDTH_LOG" | sort

echo ""

# ── Last 7 days ──────────────────────────────────────────────────────────────────────────────
echo "━━━ $ICON_BANDWIDTH Last 7 Days ━━━"
for i in 6 5 4 3 2 1 0; do
    day=$(date -d "$i days ago" '+%Y-%m-%d')
    day_name=$(date -d "$i days ago" '+%a')
    day_runs=$(awk -F'|' -v d="$day" '$1==d' "$BANDWIDTH_LOG" | wc -l)
    day_success=$(awk -F'|' -v d="$day" '$1==d && $5=="success"' "$BANDWIDTH_LOG" | wc -l)
    day_failed=$(awk -F'|' -v d="$day" '$1==d && $5=="failed"' "$BANDWIDTH_LOG" | wc -l)
    day_duration=$(awk -F'|' -v d="$day" '$1==d{sum+=$4} END{print sum+0}' "$BANDWIDTH_LOG")
    day_duration_fmt=$(format_duration "$day_duration")

    if [[ "$day_runs" -eq 0 ]]; then
        echo "  $ICON_TIME  $day ($day_name) — no syncs"
    elif [[ "$day_failed" -gt 0 ]]; then
        echo "  $ICON_WARN  $day ($day_name) — $day_runs runs / ${day_duration_fmt} total / $ICON_ERROR $day_failed failed"
    else
        echo "  $ICON_DONE  $day ($day_name) — $day_runs runs / ${day_duration_fmt} total"
    fi
done

echo ""

# ── Totals ───────────────────────────────────────────────────────────────────────────────────
TOTAL_DURATION=$(awk -F'|' '{sum+=$4} END{print sum+0}' "$BANDWIDTH_LOG")
TOTAL_DURATION_FMT=$(format_duration "$TOTAL_DURATION")

END=$(date +%s)

echo "━━━━━ $ICON_SUMMARY BANDWIDTH SUMMARY ━━━━━"
echo "$ICON_BANDWIDTH Total runs:    $ENTRY_COUNT ($SUCCESS_COUNT success / $FAILED_COUNT failed)"
echo "$ICON_TIME      Total time:    $TOTAL_DURATION_FMT"
echo "$ICON_TIME      Log period:    $OLDEST → $NEWEST"
echo "$ICON_GEAR      Retention:     ${BANDWIDTH_LOG_RETENTION} days"
echo "$ICON_TIME      Generated in:  $(format_duration $((END - START)))"
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"

notify "Bandwidth report on $(hostname) — $ENTRY_COUNT rsync runs ($SUCCESS_COUNT success / $FAILED_COUNT failed) over ${BANDWIDTH_LOG_RETENTION} day window" "Bandwidth Monitor" "normal"