#!/usr/bin/env bash
# Build the kernel with the `headless` feature and boot it in QEMU with no
# window. Serial output goes to this terminal; the kernel powers QEMU off via
# the isa-debug-exit device when done. A timeout guards against hangs.
#
# A normal boot runs the shell self-test (disk/scripts/selftest.sh); the
# shell's exit code decides success, and this script then also checks that
# the expected lines appear in the output.
#
# Usage: ./scripts/run-headless.sh                 # boot + shell self-test
#        ./scripts/run-headless.sh stack-overflow  # extra cargo features, comma separated
#        EXT2_IMG=copy.img ./scripts/run-headless.sh
#            use copy.img as the ext2 disk *without* snapshot=on, so the
#            self-test's writes land in that file (scripts/ext2-check.sh
#            then runs e2fsck on it)
#        EXFAT_IMG=copy.img ./scripts/run-headless.sh
#            the same for the exFAT disk (scripts/exfat-check.sh runs
#            fsck.exfat on it)
#        BTRFS_IMG=other.img ./scripts/run-headless.sh
#            use other.img as drive E: (read-only, so always snapshot=on)
set -euo pipefail
cd "$(dirname "$0")/.."

cargo build --features "headless${1:+,$1}"
# Force bootimage to repack the disk image (see scripts/runner.sh for why).
touch target/x86_64-rust_kernel/debug/rustbelt
cargo bootimage --features "headless${1:+,$1}"
IMG=target/x86_64-rust_kernel/debug/bootimage-rustbelt.bin

if [ -n "${EXT2_IMG:-}" ]; then
    EXT2_DRIVE="file=$EXT2_IMG,format=raw,if=virtio"
else
    EXT2_DRIVE="file=target/ext2.img,format=raw,if=virtio,snapshot=on"
fi

if [ -n "${EXFAT_IMG:-}" ]; then
    EXFAT_DRIVE="file=$EXFAT_IMG,format=raw,if=virtio"
else
    EXFAT_DRIVE="file=target/exfat.img,format=raw,if=virtio,snapshot=on"
fi

BTRFS_DRIVE="file=${BTRFS_IMG:-target/btrfs.img},format=raw,if=virtio,snapshot=on"

LOG=target/headless-serial.log
set +e
timeout 90 qemu-system-x86_64 -smp 4 \
    -drive format=raw,file="$IMG" \
    -drive file=target/disk.img,format=raw,if=virtio,snapshot=on \
    -drive "$EXT2_DRIVE" \
    -drive "$EXFAT_DRIVE" \
    -drive "$BTRFS_DRIVE" \
    -device isa-debug-exit,iobase=0xf4,iosize=0x04 \
    -serial stdio -display none -no-reboot | tee "$LOG"
code=${PIPESTATUS[0]}
set -e

# Lines the shell self-test must have printed (only for a plain boot).
if [ -z "${1:-}" ] && [ "$code" = 33 ]; then
    expect=(
        "Rustbelt 0.11.0 (stage 11: core polish) x86_64" # ver
        "[smp] 4 CPUs online"                          # smp.rs started 3 more cores
        "B:  /mnt/disk0   fat32"                       # drives
        "C:  /mnt/disk1   ext2"
        "D:  /mnt/disk2   exfat"
        "E:  /mnt/disk3   btrfs"
        "B:/ $ ls"                                     # cd B: changed the prompt
        "readme.txt  scripts/"                         # ls in columns
        "In the Rustbelt shell this disk is drive B:"  # type B:/readme.txt
        "second line"                                  # >> and <
        "       125  todo.txt"                         # cp + ls -l
        '[trace 18] open("/mnt/disk0/notes/todo.txt", 0o0) = 3'   # run --trace
        "sleep started in the background"              # start
        "[done] pid 19 (start sleep 1), exit code 0"   # wait
        "C:/ $ ls"                                     # the ext2 disk
        "Hello from the ext2 disk!"                    # cat through a symlink
        "big.txt line 12345"                           # double-indirect block
        "written by Rustbelt"                          # mkdir + create on ext2
        "-rw-r--r--        125  todo.txt"              # cp B: -> C:, ls -l
        "lrwxrwxrwx             hello-link -> hello.txt"
        "drwxr-xr-x      <DIR>  made-here/"
        "D:/ $ ls"                                     # the exFAT disk
        "This file has a long name with spaces in it." # quoted name, other case
        "MixedCase.TXT: exFAT keeps the case"          # cp D: -> C:, cat
        "hi from exFAT"                                # md + echo >, other case
        "       125  todo.txt"                         # cp B: -> D:, ls -l D:/
        "     <DIR>  New Folder/"
        "    340000  numbers.txt"
        "E:/ $ ls -l"                                  # the btrfs disk
        "lrwxrwxrwx             hello-link -> hello.txt"
        "Hello from btrfs! (an inline extent"          # inline, through a symlink
        "btrfs never overwrites a block in place"      # compressed inline extent
        " 120000  360000 2160000 big.txt"              # 17 zlib extents
        "btrfs line 119999"
        "Stage 10: a read-only btrfs driver"           # inside subvolume projects
        "sh: new.txt: Read-only file system"           # writes refused
        "rm: hello.txt: Read-only file system"
        "mkdir: newdir: Read-only file system"
        "[exit code 139]"                              # run evil
        "(overflow) killed: stack overflow"            # user stack guard zone
        "4 CPUs online (this program ran on CPU"       # sysinfo
        "  CPU3 ["
        "sh: nosuchprogram: command not found"
        "cd: there is no drive Q:"
        "A:/tmp $ pwd"
    )
    missing=0
    for line in "${expect[@]}"; do
        grep -qF -- "$line" "$LOG" || { echo "[run-headless] MISSING: $line"; missing=1; }
    done
    # Pipe results: `... | grep -i EXT | wc -l` -> 1, `dir bin | wc -l` -> 17,
    # `cat C:/chunks.txt | wc -l` (copied from E:) -> 3, and
    # `type D:/COW.TXT | wc -l` (copied from E:) -> 4.
    for n in 1 17 3 4; do
        grep -qx -- "$n" "$LOG" || { echo "[run-headless] MISSING pipe result: $n"; missing=1; }
    done
    # No memory leaks: once the shell and all ~60 programs it ran have
    # exited, exactly as many frames must be in use as before it started.
    if grep -qE '^\[memory\] ([0-9]+) frames in use before the shell, \1 after' "$LOG"; then
        echo "[run-headless] frames in use returned to the baseline"
    else
        echo "[run-headless] MISSING: frames back at the baseline after the shell"; missing=1
    fi
    [ $missing = 0 ] && echo "[run-headless] all ${#expect[@]}+4 expected shell lines found" || code=35
fi

# isa-debug-exit: QEMU exit status = (value << 1) | 1, so Success(0x10) -> 33.
case $code in
    33)  echo "[run-headless] kernel exited OK"; exit 0 ;;
    35)  echo "[run-headless] kernel reported FAILURE"; exit 1 ;;
    124) echo "[run-headless] timed out (kernel hung?)"; exit 124 ;;
    *)   echo "[run-headless] QEMU exited with $code"; exit "$code" ;;
esac