#!/bin/sh
set -e

REPO="allisonhere/tidemail"
BINARY="tidemail"
if [ -z "${INSTALL_DIR:-}" ]; then
  if [ -z "${HOME:-}" ]; then
    INSTALL_DIR=""
  else
    INSTALL_DIR="${HOME}/.local/bin"
  fi
fi

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
CYAN='\033[0;36m'
YELLOW='\033[0;33m'
BOLD='\033[1m'
DIM='\033[2m'
NC='\033[0m'

info()    { printf "  ${CYAN}→${NC} %s\n" "$1"; }
success() { printf "  ${GREEN}✓${NC} %s\n" "$1"; }
warn()    { printf "  ${DIM}!${NC} %s\n" "$1"; }
notice()  { printf "  ${YELLOW}${BOLD}! %s${NC}\n" "$1"; }
error()   { printf "  ${RED}✗${NC} %s\n" "$1" >&2; exit 1; }

quote_path() {
  printf "'%s'" "$(printf "%s" "$1" | sed "s/'/'\\\\''/g")"
}

# Delete a path we can't unlink ourselves, escalating with sudo. sudo reads
# its prompt straight from the terminal, so this works even when the script
# is piped into sh. Returns non-zero if the file is still there afterward.
sudo_rm() {
  command -v sudo >/dev/null 2>&1 || return 1
  { : </dev/tty; } 2>/dev/null || return 1
  info "Removing $1 (needs sudo)"
  sudo rm -f -- "$1" </dev/tty >/dev/tty 2>&1 || true
  [ ! -e "$1" ]
}

# Detect OS
case "$(uname -s)" in
  Linux*)  OS="linux" ;;
  Darwin*) OS="darwin" ;;
  *)       error "Unsupported OS: $(uname -s)" ;;
esac

# Detect architecture
case "$(uname -m)" in
  x86_64|amd64)   ARCH="x86_64" ;;
  aarch64|arm64)  ARCH="aarch64" ;;
  *)              error "Unsupported architecture: $(uname -m)" ;;
esac

ASSET="${BINARY}-${OS}-${ARCH}"

printf "\n  ${BOLD}TideMail Installer${NC}\n"
printf "  ${DIM}──────────────────────────────${NC}\n"
info "Platform: ${OS}/${ARCH}"

# ── Download ──────────────────────────────────────────────────────────────
# Use GitHub's /latest/download/ redirect URL — no API call needed, so no
# rate limiting and no fragile grep/sed parsing of the releases JSON.
URL="https://github.com/${REPO}/releases/latest/download/${ASSET}.tar.gz"
TMP=$(mktemp -d)
INSTALL_TMP=""
cleanup() {
  rm -rf "$TMP"
  if [ -n "$INSTALL_TMP" ]; then
    rm -f "$INSTALL_TMP"
  fi
}
trap cleanup EXIT
trap 'cleanup; exit 130' INT
trap 'cleanup; exit 143' TERM

info "Downloading latest release..."
if ! curl -fsSL -o "${TMP}/${ASSET}.tar.gz" "$URL"; then
  rm -rf "$TMP"
  error "Download failed — no release asset at ${URL}\n         Check that a release exists: https://github.com/${REPO}/releases"
fi

# Verify we got a real gzip archive (not an HTML error page from a redirect).
if ! gzip -t "${TMP}/${ASSET}.tar.gz" 2>/dev/null; then
  rm -rf "$TMP"
  error "Downloaded file is not a valid archive. The latest release may be missing ${OS}/${ARCH} assets.\n         See: https://github.com/${REPO}/releases"
fi

# ── Extract ───────────────────────────────────────────────────────────────
info "Extracting..."
if ! tar -xzf "${TMP}/${ASSET}.tar.gz" -C "$TMP"; then
  rm -rf "$TMP"
  error "Failed to extract ${ASSET}.tar.gz — the archive may be corrupt."
fi

if [ ! -f "${TMP}/${ASSET}" ]; then
  contents=$(ls -A "$TMP" 2>/dev/null | tr '\n' ' ')
  error "Archive does not contain expected binary '${ASSET}'.\n         Found instead: ${contents}"
fi

chmod +x "${TMP}/${ASSET}"

# Verify the staged binary before touching any existing installation.
if ! "${TMP}/${ASSET}" --version >/dev/null 2>&1; then
  error "Downloaded binary failed its version check; existing installation left untouched."
fi

# ── Install ───────────────────────────────────────────────────────────────
if [ -z "$INSTALL_DIR" ]; then
  error "No install directory selected. Set INSTALL_DIR to a writable directory."
fi

if [ ! -d "$INSTALL_DIR" ]; then
  info "Creating ${INSTALL_DIR}"
  if ! mkdir -p "$INSTALL_DIR"; then
    error "Could not create ${INSTALL_DIR}. Set INSTALL_DIR to a writable directory."
  fi
fi

if [ ! -w "$INSTALL_DIR" ]; then
  error "${INSTALL_DIR} is not writable. Existing installation left untouched.\n         Try: INSTALL_DIR=\"\$HOME/.local/bin\" sh install.sh"
fi

INSTALL_TMP="${INSTALL_DIR}/.${BINARY}.tmp.$$"
info "Installing to ${INSTALL_DIR}/${BINARY}"
if ! install -m 0755 "${TMP}/${ASSET}" "$INSTALL_TMP"; then
  error "Could not stage binary in ${INSTALL_DIR}. Existing installation left untouched."
fi

if ! VERSION=$("$INSTALL_TMP" --version 2>/dev/null); then
  error "Staged binary failed its version check; existing installation left untouched."
fi

mv -f "$INSTALL_TMP" "${INSTALL_DIR}/${BINARY}"
INSTALL_TMP=""

# ── Verify ────────────────────────────────────────────────────────────────
success "Installed ${VERSION} to ${INSTALL_DIR}/${BINARY}"
notice "Google OAuth is waiting for Google's approval. Use a Google App Password for Gmail."

# ── Man page ──────────────────────────────────────────────────────────────
# The page is embedded in the binary, so it always matches this version. Best
# effort: a failure here never fails the install. man-db finds
# ~/.local/share/man from a ~/.local/bin entry on PATH.
if [ -n "${XDG_DATA_HOME:-}" ] || [ -n "${HOME:-}" ]; then
  MAN_DIR="${XDG_DATA_HOME:-${HOME}/.local/share}/man/man1"
  if mkdir -p "$MAN_DIR" 2>/dev/null \
    && "${INSTALL_DIR}/${BINARY}" man > "${TMP}/${BINARY}.1" 2>/dev/null \
    && [ -s "${TMP}/${BINARY}.1" ] \
    && install -m 0644 "${TMP}/${BINARY}.1" "${MAN_DIR}/${BINARY}.1" 2>/dev/null; then
    success "Installed the manual page: man ${BINARY}"
  else
    warn "Could not install the manual page; read it with: ${BINARY} man | man -l -"
  fi
fi

# ── Launcher entry (Linux) ────────────────────────────────────────────────
# Adds TideMail to the app launcher (Omarchy's Walker, GNOME, KDE, rofi...).
# Best effort: a failure here never fails the install. The entry runs the
# installed binary by absolute path in the user's default terminal.
if [ "$OS" = "linux" ] && { [ -n "${XDG_DATA_HOME:-}" ] || [ -n "${HOME:-}" ]; }; then
  DATA_DIR="${XDG_DATA_HOME:-${HOME}/.local/share}"
  ICON_URL="https://raw.githubusercontent.com/${REPO}/main/images/tidemail-icon.png"
  APP_DIR="${DATA_DIR}/applications"
  ICON_DIR="${DATA_DIR}/icons"
  ICON_OK=""
  if mkdir -p "$APP_DIR" "$ICON_DIR" 2>/dev/null \
    && curl -fsSL -o "${TMP}/${BINARY}.png" "$ICON_URL" 2>/dev/null \
    && [ -s "${TMP}/${BINARY}.png" ] \
    && install -m 0644 "${TMP}/${BINARY}.png" "${ICON_DIR}/${BINARY}.png" 2>/dev/null; then
    ICON_OK=1
  fi
  cat > "${TMP}/${BINARY}.desktop" <<DESKTOP
[Desktop Entry]
Type=Application
Name=TideMail
GenericName=Mail Client
Comment=Keyboard-first terminal email client
Exec="${INSTALL_DIR}/${BINARY}"
Icon=${ICON_OK:+${ICON_DIR}/${BINARY}.png}
Terminal=true
Categories=Network;Email;ConsoleOnly;
Keywords=mail;email;imap;smtp;inbox;terminal;
DESKTOP
  if [ -z "$ICON_OK" ]; then
    sed -i 's/^Icon=$/Icon=mail-unread/' "${TMP}/${BINARY}.desktop"
  fi
  if install -m 0644 "${TMP}/${BINARY}.desktop" "${APP_DIR}/${BINARY}.desktop" 2>/dev/null; then
    command -v update-desktop-database >/dev/null 2>&1 && update-desktop-database "$APP_DIR" >/dev/null 2>&1 || true
    success "Added TideMail to your app launcher"
  else
    warn "Could not add the launcher entry; see the App launcher section of docs/guide.md"
  fi
fi

# Resolve a directory to its canonical, symlink-free form so alternate
# spellings of the same directory on PATH ("..", symlinks, trailing slashes)
# are recognised as our install dir and never deleted as a "stale" copy.
canon_dir() { ( CDPATH= cd -- "$1" 2>/dev/null && pwd -P ); }
INSTALL_DIR_CANON=$(canon_dir "$INSTALL_DIR") || INSTALL_DIR_CANON=""
[ -n "$INSTALL_DIR_CANON" ] || INSTALL_DIR_CANON="$INSTALL_DIR"

# Walk *every* directory on PATH — not just the ones before our install dir.
# Copies earlier on PATH would shadow the new build; copies later are already
# shadowed by it but are still removed so `which -a ${BINARY}` stays clean.
SHADOWED=""
SHADOWED_CMD=""
FOUND_INSTALLED=""
PASSED_INSTALL_DIR=""
LATER_LEFT=""
OLD_IFS=$IFS
IFS=:
for dir in $PATH; do
  [ -n "$dir" ] || dir="."

  dir_canon=$(canon_dir "$dir") || dir_canon=""
  [ -n "$dir_canon" ] || dir_canon="$dir"
  if [ "$dir_canon" = "$INSTALL_DIR_CANON" ]; then
    FOUND_INSTALLED=1
    PASSED_INSTALL_DIR=1
    continue
  fi

  candidate="${dir}/${BINARY}"
  if [ ! -f "$candidate" ] || [ ! -x "$candidate" ]; then
    continue
  fi

  if { [ -w "$dir" ] && rm -f "$candidate"; } || sudo_rm "$candidate"; then
    if [ -n "$PASSED_INSTALL_DIR" ]; then
      success "Removed shadowed ${candidate} that appeared later on PATH"
    else
      success "Removed stale ${candidate} that appeared earlier on PATH"
    fi
    continue
  fi

  # Still there — no sudo, no terminal to prompt on, or the user declined.
  # A later copy is harmless (ours already wins); just note it. An earlier
  # copy still shadows us: print the command to finish the job and stop.
  if [ -n "$PASSED_INSTALL_DIR" ]; then
    LATER_LEFT="$candidate"
    continue
  fi
  SHADOWED="$candidate"
  SHADOWED_CMD="sudo rm -f $(quote_path "$candidate")"
  break
done
IFS=$OLD_IFS

case ":$PATH:" in
  *":$INSTALL_DIR:"*) ;;
  *) warn "${INSTALL_DIR} is not on PATH; add it before running ${BINARY} by name." ;;
esac
if [ -n "$SHADOWED" ]; then
  warn "${SHADOWED} appears before ${INSTALL_DIR}/${BINARY} on PATH, so it may still run first."
  warn "Remove it with: ${SHADOWED_CMD}"
elif [ -n "$LATER_LEFT" ]; then
  warn "${LATER_LEFT} is still on PATH but shadowed by ${INSTALL_DIR}/${BINARY}; remove it at your leisure."
elif [ -z "$FOUND_INSTALLED" ]; then
  warn "${INSTALL_DIR}/${BINARY} is not before other ${BINARY} entries on PATH."
fi
printf "\n  Run ${BOLD}tidemail${NC} to get started.\n\n"