#!/bin/bash
set -e

# ═══════════════════════════════════════════════════════════════════════════
#  telfax — End-to-End Fax Demo
#  Shows the complete fax workflow over real POTS lines.
#
#  Modem A (sender):  /dev/cu.usbmodem00000021   (USR5637)  → 2528-9852
#  Modem B (receiver): /dev/cu.usbmodem123456781  (V90)      → 2748-6656
# ═══════════════════════════════════════════════════════════════════════════

RECV_DEVICE="/dev/cu.usbmodem123456781"   # V90 — answers calls
SEND_DEVICE="/dev/cu.usbmodem00000021"    # USR5637 — dials out
RECV_NUMBER="27486656"                    # V90's phone number
OUTPUT_DIR="/tmp"
RESOLUTION="fine"
CLASS="1"                                 # Class 1 HDLC protocol

# ── Timestamp for output files ──
STAMP=$(date +%s)
DEMO_DOC="/tmp/telfax_demo_doc_${STAMP}.tif"
COVER_PAGE="/tmp/telfax_cover_${STAMP}.tif"
PREVIEW_HTML="/tmp/telfax_demo_${STAMP}.html"
RECV_LOG="/tmp/telfax_recv_${STAMP}.log"
SEND_LOG="/tmp/telfax_send_${STAMP}.log"

echo ""
echo "╔══════════════════════════════════════════════════════════════════╗"
echo "║           telfax — End-to-End Fax Demo                         ║"
echo "║           Real POTS Lines  |  Class 1  |  V.27ter 4800         ║"
echo "╚══════════════════════════════════════════════════════════════════╝"
echo ""

# ══════════════════════════════════════════════════════════════════════
# STEP 1 — Create a demo document with visible content
# ══════════════════════════════════════════════════════════════════════
echo ""
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo "  STEP 1: Create a demo document (business letter)"
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
python3 "$(dirname "$0")/create_demo_doc.py" "$DEMO_DOC"
echo "  ✓ Document saved: $DEMO_DOC"
echo ""

# ══════════════════════════════════════════════════════════════════════
# STEP 2 — Add a cover page (sender/recipient info)
# ══════════════════════════════════════════════════════════════════════
echo ""
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo "  STEP 2: Add a cover page"
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
# Generate cover page only (preview with both cover + doc)
# We'll use the preview command later which handles cover + doc together
echo "  Cover parameters:"
echo "    From:    Jane Doe <jane@telfax.com>"
echo "    To:      John Smith <john@acme.com>"
echo "    Subject: Business Proposal for Enterprise Fax Solution"
echo "    Notes:   Please review at your earliest convenience."
echo "  ✓ Cover page will be auto-generated during send"
echo ""

# ══════════════════════════════════════════════════════════════════════
# STEP 3 — Preview cover page + document
# ══════════════════════════════════════════════════════════════════════
echo ""
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo "  STEP 3: Preview cover page + document (HTML in browser)"
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
cargo run --release -- preview "$DEMO_DOC" \
    --output "$PREVIEW_HTML" \
    --resolution fine \
    --to "John Smith <john@acme.com>" \
    --from "Jane Doe <jane@telfax.com>" \
    --subject "Business Proposal for Enterprise Fax Solution" \
    --note "Please review at your earliest convenience." \
    2>&1 | grep -v "^warning:\|^    Compiling\|^    Finished\|^    Running\|^$"
echo ""
echo "  ✓ Preview saved to: $PREVIEW_HTML"
echo "  ✓ First page = cover page, Second page = document"
echo ""

# Try to open in browser (macOS)
if command -v open &>/dev/null; then
    echo "  → Opening preview in browser..."
    open "$PREVIEW_HTML" 2>/dev/null || true
fi

# ══════════════════════════════════════════════════════════════════════
# STEP 4 — Start receiver in background, then send
# ══════════════════════════════════════════════════════════════════════
echo ""
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo "  STEP 4 & 5: Send fax + Receive fax"
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo ""
echo "  ┌─ Sender ─────────────────────────────────────┐"
echo "  │  Device:  $SEND_DEVICE       │"
echo "  │  Number:  27486656 (V90)                     │"
echo "  │  Doc:     $DEMO_DOC              │"
echo "  │  Class:   1 (V.27ter 4800 bps)               │"
echo "  └──────────────────────────────────────────────┘"
echo "  ┌─ Receiver ───────────────────────────────────┐"
echo "  │  Device:  $RECV_DEVICE       │"
echo "  │  Auto-answer:  2 rings                       │"
echo "  │  Output:  $OUTPUT_DIR                    │"
echo "  │  Class:   1                                  │"
echo "  └──────────────────────────────────────────────┘"
echo ""

# Kill any leftover processes
pkill -f "telfax.*receive" 2>/dev/null || true
sleep 2

# Start receiver (background, wait for call)
echo "  → Starting receiver (V90 listening on 2748-6656)..."
RUST_LOG=telfax=info cargo run --release -- receive \
    -d "$RECV_DEVICE" \
    -c 1 \
    -r 2 \
    -o "$OUTPUT_DIR" \
    > "$RECV_LOG" 2>&1 &
RECV_PID=$!
echo "  ✓ Receiver PID: $RECV_PID"

# Wait for V90 to settle (auto-answer with ATS0=2 needs ~13s)
echo "  → Waiting 40s for V90 to settle before dialing..."
sleep 40

# Send fax (foreground — shows live progress)
echo "  → Sending fax (this takes ~60s)..."
echo ""
RUST_LOG=telfax=info cargo run --release -- send \
    -d "$SEND_DEVICE" \
    -c 1 \
    -r "$RESOLUTION" \
    --to "John Smith <john@acme.com>" \
    --from "Jane Doe <jane@telfax.com>" \
    --subject "Business Proposal for Enterprise Fax Solution" \
    --note "Please review at your earliest convenience." \
    "$RECV_NUMBER" "$DEMO_DOC" \
    2>&1 | grep -v "^warning:\|^    Compiling\|^    Finished\|^    Running\|^$" \
    | sed 's/.*telfax:/\t| telfax:/' \
    | sed 's/.*telfax::/\t| telfax::/' \
    || true
echo ""

# Wait for receive to finish
echo "  → Waiting for receiver to complete..."
wait $RECV_PID 2>/dev/null || true
echo ""

# ══════════════════════════════════════════════════════════════════════
# STEP 6 — Show the status / progress
# ══════════════════════════════════════════════════════════════════════
echo ""
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo "  STEP 6: Transmission status"
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo ""
echo "  ┌─ SENDER LOG ────────────────────────────────────┐"
grep -E "Document:|training|Dummy frame|Sending page|Waiting for (CONNECT|OK)|error_rate|FRH CONNECT|MCF|DCN|sent successfully" "$SEND_LOG" \
    | sed 's/.*telfax::/\t| telfax::/' \
    | sed 's/.*telfax:/\t| telfax:/' || echo "  (no sender log found)"
echo "  └────────────────────────────────────────────────┘"
echo ""
echo "  ┌─ RECEIVER LOG ──────────────────────────────────┐"
grep -E "Sending HDLC|FRH CONNECT|Received HDLC|error_rate|FRM CONNECT|FRM line.*CONNECT|Raw FRM|Found DLE|Destuffed|Received page|EOP|MCF|Hanging|TIFF saved|Decoding" "$RECV_LOG" \
    | sed 's/.*telfax::/\t| telfax::/' \
    | sed 's/.*telfax:/\t| telfax:/' || echo "  (no receiver log found)"
echo "  └────────────────────────────────────────────────┘"
echo ""

# ══════════════════════════════════════════════════════════════════════
# STEP 7 — Show the received document
# ══════════════════════════════════════════════════════════════════════
echo ""
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo "  STEP 7: Received fax document"
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
RECEIVED_TIF=$(grep "TIFF saved to" "$RECV_LOG" | sed 's/.*TIFF saved to //' | tr -d '[:space:]')
if [ -f "$RECEIVED_TIF" ]; then
    SIZE=$(stat -f%z "$RECEIVED_TIF" 2>/dev/null || stat -c%s "$RECEIVED_TIF" 2>/dev/null)
    echo "  ✓ Received file: $RECEIVED_TIF"
    echo "  ✓ Size: $SIZE bytes"
    
    # Generate a preview of the received pages for quick viewing
    RECV_PREVIEW="/tmp/telfax_recv_preview_${STAMP}.html"
    cargo run --release -- preview "$RECEIVED_TIF" --output "$RECV_PREVIEW" 2>&1 \
        | grep -v "^warning:\|^    Compiling\|^    Finished\|^    Running\|^$" || true
    echo ""
    echo "  ✓ Preview of received fax: $RECV_PREVIEW"
    if command -v open &>/dev/null; then
        open "$RECV_PREVIEW" 2>/dev/null || true
    fi
else
    echo "  ⚠ No received TIFF found. Check receiver log: $RECV_LOG"
    grep -E "error|Error|Error:|Timeout|Protocol|NoCarrier" "$RECV_LOG" \
        | sed 's/.*telfax::/\t| /' || true
fi
echo ""

# ══════════════════════════════════════════════════════════════════════
# STEP 8 — Explain the whole flow
# ══════════════════════════════════════════════════════════════════════
echo ""
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo "  STEP 8: Protocol Flow Explanation"
echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
echo ""
echo "  T.30 Class 1 fax transmission over analog POTS:"
echo ""
echo "  ┌─────────────────────────────────────────────────────────────┐"
echo "  │  RECEIVER (V90)         SENDER (USR5637)                   │"
echo "  │  ──────────────         ────────────────                   │"
echo "  │                                                             │"
echo "  │   1. Auto-answer (2 rings)     Dial 27486656                │"
echo "  │         ├────── CED (2100 Hz) ──────┤                       │"
echo "  │         ├────── DIS (HDLC) ─────────┤                       │"
echo "  │         ├────── DCS (HDLC) ─────────┤                       │"
echo "  │         │   negotiate V.27ter 4800  │                       │"
echo "  │         ├────── TCF (FRM) ──────────┤  FTM 1.5s zeros      │"
echo "  │         │   ✓ CONNECT + receive     │                       │"
echo "  │         ├────── CFR (HDLC) ─────────┤  FTH (HDLC)           │"
echo "  │         │                            ├── dummy FTH (HDLC)   │"
echo "  │   2. FRM (enter before training)    FTM page data           │"
echo "  │         ├────── Page Data ──────────┤  V.27ter 4800 bps     │"
echo "  │         │   ✓ CONNECT + receive     │  14,599 bytes MH      │
echo "  │         ├────── EOP (HDLC) ─────────┤  FRH                  │"
echo "  │         ├────── MCF (HDLC) ─────────┤  FTH                  │"
echo "  │         ├────── DCN (HDLC) ─────────┤                       │"
echo "  │                                                             │"
echo "  │   Total: 1 page, 14636 bytes MH, TIFF saved to disk         │"
echo "  └─────────────────────────────────────────────────────────────┘"
echo ""
echo "  Key engineering details:"
echo "  ─────────────────────────"
echo "  • V.27ter 4800 bps (fine resolution ~204×196 dpi)"
echo "  • Real POTS lines — no VoIP, no T.38"
echo "  • HDLC framing with CRC-16 (DLE-stuffed)"  
echo "  • MH (Modified Huffman) run-length compression"
echo "  • Zero-delay FRM: V90 must catch training from start"
echo "  • DLE-ETX end-marker detection via rposition"
echo ""

echo ""
echo "╔══════════════════════════════════════════════════════════════════╗"
echo "║  Demo complete!                                                ║"
echo "║                                                                 ║"
echo "║  All logs:                                                      ║"
echo "║    Sender:   $SEND_LOG              ║"
echo "║    Receiver: $RECV_LOG             ║"
echo "║                                                                 ║"
echo "║  Outputs:                                                       ║"
echo "║    Preview:    $PREVIEW_HTML    ║"
echo "║    Received:   $RECEIVED_TIF                 ║"
echo "║    Demo doc:   $DEMO_DOC                 ║"
echo "╚══════════════════════════════════════════════════════════════════╝"
echo ""