#!/usr/bin/env bash
set -euo pipefail
# POS: system uninstall — Remove pos toolkit binaries, services, shell integration, config, and data
# POS_FLAGS: --yes --config --data
source "$(dirname "$0")/../lib/common.sh" 2>/dev/null || source "$(dirname "$0")/common.sh"

usage() {
    cat <<'EOF'
Usage: pos system uninstall [--yes] [--config] [--data]

Remove the pos toolkit from this machine. Scans for installed components
and removes them interactively (or non-interactively with --yes).

Tiers:
  Tier 1 (always):  binaries, entertainment plugins, systemd services, shell integration
  Tier 2 (--config): config files in ~/.config/linux_post_install/
  Tier 3 (--data):   session/log/capture data in ~/.local/share/linux_post_install/

Flags:
  --yes     Skip confirmation prompts (removes defaults only; combine with --config/--data for more)
  --config  Include config files (Tier 2) in removal
  --data    Include session/log data (Tier 3) in removal

Examples:
  pos system uninstall                   # interactive, tier 1 only
  pos system uninstall --yes             # non-interactive, tier 1 only
  pos system uninstall --yes --config --data   # nuclear option

Intentionally NOT removed (user-managed):
  - apt packages (system packages installed by preinstall.sh)
  - /usr/local/bin/yt-dlp (manually installed)
  - ~/.config/rclone/ (rclone manages its own config)
  - ~/.ssh/authorized_keys additions (user SSH access)
  - pos-owned config files (removed by --config tier)
  - pos-owned data files (removed by --data tier)
EOF
    exit 0
}

# ── Parse flags ─────────────────────────────────────────────────
YES_MODE=0
DEL_CONFIG=0
DEL_DATA=0
while [ $# -gt 0 ]; do
    case "$1" in
        -h|--help) usage ;;
        --yes)     YES_MODE=1; shift ;;
        --config)  DEL_CONFIG=1; shift ;;
        --data)    DEL_DATA=1; shift ;;
        -*)        err "Unknown option '$1'" ;;
        *)         err "Unexpected argument: $1 (no subcommands)" ;;
    esac
done

# ── pos-owned installed files (single source of truth, mirrors install.sh) ──
# lib/*.sh list shipped by install.sh phase 2 to /usr/local/bin.
POS_LIBS=(common.sh flags.sh notify.sh entertainment-lib.sh scheduler-lib.sh config-ui.sh \
    user-timers-lib.sh entertainment-plugin-lib.sh usb-lib.sh share-lib.sh menu-lib.sh registry.sh \
    yt-lib.sh bank-lib.sh)
# Exact lines postinstall.sh appends to ~/.bashrc.
PATH_LINE='export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:$HOME/.local/bin:$PATH"'
COMPLETION_LINE='source /usr/local/share/bash-completion/completions/pos.bash 2>/dev/null || true'
# Pos-ai-hook source lines are not written by the installer (user/legacy-added),
# so they are matched by an anchored source-pattern, never a bare substring.
HOOK_PATTERN='^[[:space:]]*source[[:space:]].*pos-ai-hook\.sh'

# Entertainment plugins installed by install.sh — discovered by POS_PLUGIN marker
# so future plugins are removed without touching this file.
installed_plugins() {
    local ep
    for ep in /usr/local/bin/*.sh; do
        [ -f "$ep" ] || continue
        grep -q '^# POS_PLUGIN:' "$ep" 2>/dev/null && echo "$ep"
    done | sort
}

# ── Scan functions ──────────────────────────────────────────────
scan_tier1() {
    local found=()

    # ── Binaries in /usr/local/bin ──
    # Main dispatcher
    [ -f /usr/local/bin/pos ] && found+=("/usr/local/bin/pos")

    # All pos-* tools (sorted for deterministic display)
    local f
    while IFS= read -r f; do
        found+=("$f")
    done < <(compgen -G /usr/local/bin/pos-* 2>/dev/null | sort || true)

    # Lib files shipped by install.sh (single source: POS_LIBS)
    for f in "${POS_LIBS[@]}"; do
        [ -f "/usr/local/bin/$f" ] && found+=("/usr/local/bin/$f")
    done

    # AI providers subdirectory
    [ -d /usr/local/bin/ai-providers ] && found+=("/usr/local/bin/ai-providers/")

    # Entertainment plugins installed by install.sh (discovered by POS_PLUGIN marker)
    while IFS= read -r f; do
        [ -n "$f" ] && found+=("$f")
    done < <(installed_plugins)

    # Legacy forwarders
    for f in wr-* mp3 mp4 vbox ssh-load-all; do
        if compgen -G "/usr/local/bin/$f" >/dev/null 2>&1; then
            while IFS= read -r lf; do
                found+=("$lf")
            done < <(compgen -G "/usr/local/bin/$f" 2>/dev/null)
        fi
    done

    # Prebuilt binaries (hotspot)
    for f in wihotspot wihotspot-gui create_ap; do
        [ -f "/usr/local/bin/$f" ] && found+=("/usr/local/bin/$f")
    done

    # Feature scripts installed by install.sh
    for f in autostart.sh usb-automount.sh; do
        [ -f "/usr/local/bin/$f" ] && found+=("/usr/local/bin/$f")
    done

    # User-local binaries
    [ -f "$HOME/.local/bin/pos-ai-hook.sh" ] && found+=("$HOME/.local/bin/pos-ai-hook.sh")

    # pos ai alias wrapper scripts (marker-managed)
    if [ -d "$HOME/.local/bin" ]; then
        local awf
        for awf in "$HOME/.local/bin"/*; do
            [ -f "$awf" ] || continue
            grep -q 'Managed by pos ai alias' "$awf" 2>/dev/null && found+=("$awf")
        done
    fi

    # Completion file
    [ -f /usr/local/share/bash-completion/completions/pos.bash ] && found+=("/usr/local/share/bash-completion/completions/pos.bash")

    # ~/.bash_completion entries (anchored source lines only, never /pos/ substring)
    if [ -f "$HOME/.bash_completion" ]; then
        while IFS= read -r line; do
            found+=("~/.bash_completion: $(echo "$line" | sed 's/^[[:space:]]*//' | cut -c1-70)")
        done < <(grep -nE '^[[:space:]]*source[[:space:]].*pos\.bash' "$HOME/.bash_completion" 2>/dev/null || true)
    fi

    # ── Systemd services ──
    for svc in autostart.service ssh-agent.service usb-automount.service; do
        if systemctl is-enabled "$svc" &>/dev/null 2>&1; then
            found+=("service: $svc")
        elif [ -f "/etc/systemd/system/$svc" ]; then
            found+=("service: $svc")
        fi
    done
    # Catch any other linux_post_install-related services
    while IFS= read -r line; do
        local svc_name
        svc_name=$(echo "$line" | awk '{print $1}')
        # Skip already-listed services
        local already=0
        for listed in autostart.service ssh-agent.service usb-automount.service; do
            [ "$svc_name" = "$listed" ] && already=1 && break
        done
        [ "$already" -eq 0 ] && found+=("service: $svc_name")
    done < <(systemctl list-unit-files --type=service 2>/dev/null | grep -i 'linux_post_install\|pos-' || true)

    # ── ScaleTail templates + feature-flag store (install.sh phase 2/4) ──
    [ -d /usr/local/share/linux_post_install/scale-tail ] && found+=("/usr/local/share/linux_post_install/scale-tail/")
    [ -d /usr/local/share/linux_post_install/flags ] && found+=("/usr/local/share/linux_post_install/flags/")

    # ── Runtime-created user units (pos-* in ~/.config/systemd/user) ──
    local user_unit_dir="${XDG_CONFIG_HOME:-$HOME/.config}/systemd/user"
    if [ -d "$user_unit_dir" ]; then
        local ufile
        while IFS= read -r ufile; do
            [ -n "$ufile" ] && found+=("user-unit: $(basename "$ufile")")
        done < <(find "$user_unit_dir" -maxdepth 1 -name 'pos-*' -type f 2>/dev/null || true)
    fi

    # ── Shell integration (~/.bashrc) — exact installer lines + anchored hook ──
    if [ -f "$HOME/.bashrc" ]; then
        while IFS= read -r line; do
            found+=("~/.bashrc: $(echo "$line" | sed 's/^[[:space:]]*//' | cut -c1-70)")
        done < <({ grep -nF "$PATH_LINE" "$HOME/.bashrc"; grep -nF "$COMPLETION_LINE" "$HOME/.bashrc"; grep -nE "$HOOK_PATTERN" "$HOME/.bashrc"; } 2>/dev/null | sort -u || true)
    fi

    printf '%s\n' "${found[@]}"
}

scan_tier2() {
    local found=()
    local cfg="$HOME/.config/linux_post_install"
    if [ -d "$cfg" ]; then
        while IFS= read -r f; do
            found+=("$f")
        done < <(find "$cfg" -maxdepth 2 -type f 2>/dev/null | sort)
    fi
    printf '%s\n' "${found[@]}"
}

scan_tier3() {
    local found=()
    local data="$HOME/.local/share/linux_post_install"
    if [ -d "$data" ]; then
        while IFS= read -r f; do
            found+=("$f")
        done < <(find "$data" -maxdepth 2 \( -type f -o -type d \) 2>/dev/null | sort)
    fi
    printf '%s\n' "${found[@]}"
}

# ── Display function ────────────────────────────────────────────
display_plan() {
    local -a t1=() t2=() t3=()
    # Collect non-empty entries from scan output
    while IFS= read -r line; do
        [ -n "$line" ] && t1+=("$line")
    done <<< "${1:-}"
    while IFS= read -r line; do
        [ -n "$line" ] && t2+=("$line")
    done <<< "${2:-}"
    while IFS= read -r line; do
        [ -n "$line" ] && t3+=("$line")
    done <<< "${3:-}"

    echo
    echo "${BOLD}pos uninstall — what will be removed:${RESET}"
    echo

    local n=1

    if [ "${#t1[@]}" -gt 0 ]; then
        echo "${CYAN}Tier 1 (always):${RESET}"
        for item in "${t1[@]}"; do
            printf "  %3d) %s\n" "$n" "$item"
            n=$((n + 1))
        done
    else
        echo "${CYAN}Tier 1 (always):${RESET}  (nothing found)"
    fi
    echo

    if [ "${#t2[@]}" -gt 0 ]; then
        echo "${YELLOW}Tier 2 (--config to include):${RESET}"
        for item in "${t2[@]}"; do
            printf "  %3d) %s\n" "$n" "$item"
            n=$((n + 1))
        done
    else
        echo "${YELLOW}Tier 2 (--config to include):${RESET}  (nothing found)"
    fi
    echo

    if [ "${#t3[@]}" -gt 0 ]; then
        echo "${YELLOW}Tier 3 (--data to include):${RESET}"
        for item in "${t3[@]}"; do
            printf "  %3d) %s\n" "$n" "$item"
            n=$((n + 1))
        done
    else
        echo "${YELLOW}Tier 3 (--data to include):${RESET}  (nothing found)"
    fi
    echo
}

# ── Removal functions ───────────────────────────────────────────
remove_tier1() {
    local count=0

    # ── Binaries ──
    # Main dispatcher
    [ -f /usr/local/bin/pos ] && { rm -f /usr/local/bin/pos && count=$((count+1)); }

    # All pos-* tools
    local f
    while IFS= read -r f; do
        [ -f "$f" ] && { rm -f "$f" && count=$((count+1)); }
    done < <(compgen -G /usr/local/bin/pos-* 2>/dev/null | sort || true)

    # Lib files (single source: POS_LIBS)
    for f in "${POS_LIBS[@]}"; do
        [ -f "/usr/local/bin/$f" ] && { rm -f "/usr/local/bin/$f" && count=$((count+1)); }
    done

    # AI providers directory
    if [ -d /usr/local/bin/ai-providers ]; then
        rm -rf /usr/local/bin/ai-providers && count=$((count+1))
    fi

    # Entertainment plugins (discovered by POS_PLUGIN marker)
    while IFS= read -r f; do
        [ -n "$f" ] && [ -f "$f" ] && { rm -f "$f" && count=$((count+1)); }
    done < <(installed_plugins)

    # Legacy forwarders
    for pat in 'wr-*' mp3 mp4 vbox ssh-load-all; do
        while IFS= read -r f; do
            [ -f "$f" ] && { rm -f "$f" && count=$((count+1)); }
        done < <(compgen -G "/usr/local/bin/$pat" 2>/dev/null || true)
    done

    # Prebuilt binaries
    for f in /usr/local/bin/wihotspot /usr/local/bin/wihotspot-gui /usr/local/bin/create_ap; do
        [ -f "$f" ] && { rm -f "$f" && count=$((count+1)); }
    done

    # Feature scripts
    for f in /usr/local/bin/autostart.sh /usr/local/bin/usb-automount.sh; do
        [ -f "$f" ] && { rm -f "$f" && count=$((count+1)); }
    done

    # User-local binaries
    [ -f "$HOME/.local/bin/pos-ai-hook.sh" ] && { rm -f "$HOME/.local/bin/pos-ai-hook.sh" && count=$((count+1)); }

    # pos ai alias wrapper scripts (marker-managed only — foreign files untouched)
    if [ -d "$HOME/.local/bin" ]; then
        local arwf
        for arwf in "$HOME/.local/bin"/*; do
            [ -f "$arwf" ] || continue
            if grep -q 'Managed by pos ai alias' "$arwf" 2>/dev/null; then
                rm -f "$arwf" && count=$((count+1))
            fi
        done
    fi

    # Completion file
    [ -f /usr/local/share/bash-completion/completions/pos.bash ] && { rm -f /usr/local/share/bash-completion/completions/pos.bash && count=$((count+1)); }

    # ── Systemd services ──
    for svc in autostart.service ssh-agent.service usb-automount.service; do
        if systemctl is-enabled "$svc" &>/dev/null 2>&1; then
            systemctl disable --now "$svc" 2>/dev/null || true
            rm -f "/etc/systemd/system/$svc"
            count=$((count+1))
        elif [ -f "/etc/systemd/system/$svc" ]; then
            rm -f "/etc/systemd/system/$svc"
            count=$((count+1))
        fi
    done
    # Additional linux_post_install services
    while IFS= read -r svc_file; do
        local svc_name
        svc_name=$(basename "$svc_file" .service)
        # Skip already-handled services
        local already=0
        for listed in autostart ssh-agent usb-automount; do
            [ "$svc_name" = "$listed" ] && already=1 && break
        done
        if [ "$already" -eq 0 ]; then
            systemctl disable --now "$svc_name.service" 2>/dev/null || true
            rm -f "$svc_file"
            count=$((count+1))
        fi
    done < <(find /etc/systemd/system/ -name '*linux_post_install*' -o -name 'pos-*' 2>/dev/null || true)

    # Reload daemon after service changes
    systemctl daemon-reload 2>/dev/null || true

    # ── Runtime-created USER systemd units (pos-* in ~/.config/systemd/user) ──
    # Wrapped `|| true`: no user session (e.g. running as a scheduled task) is fine.
    local user_unit_dir="${XDG_CONFIG_HOME:-$HOME/.config}/systemd/user"
    if [ -d "$user_unit_dir" ]; then
        local ufile uniname
        while IFS= read -r ufile; do
            [ -n "$ufile" ] || continue
            uniname="$(basename "$ufile")"
            systemctl --user disable --now "$uniname" 2>/dev/null || true
            rm -f "$ufile" && count=$((count+1))
        done < <(find "$user_unit_dir" -maxdepth 1 -name 'pos-*' -type f 2>/dev/null || true)
        systemctl --user daemon-reload 2>/dev/null || true
    fi

    # ── ScaleTail templates (submodule clone — guard existence) ──
    if [ -d /usr/local/share/linux_post_install/scale-tail ]; then
        rm -rf /usr/local/share/linux_post_install/scale-tail && count=$((count+1))
    fi

    # ── Feature-flag store ──
    if [ -d /usr/local/share/linux_post_install/flags ]; then
        rm -rf /usr/local/share/linux_post_install/flags && count=$((count+1))
    fi

    # Clean up parent dir if empty
    rmdir /usr/local/share/linux_post_install 2>/dev/null || true

    # ── Shell integration (~/.bashrc) — exact installer lines + anchored hook ──
    # Only lines postinstall.sh itself added are removed by exact literal match;
    # pos-ai-hook lines are matched anchored (never a bare substring).
    if [ -f "$HOME/.bashrc" ]; then
        local before after removed tmp
        before=$(wc -l < "$HOME/.bashrc")
        tmp="$(mktemp)"
        awk -v p="$PATH_LINE" -v c="$COMPLETION_LINE" -v h="$HOOK_PATTERN" '
            $0 == p || $0 == c || $0 ~ h { next }
            { print }
        ' "$HOME/.bashrc" > "$tmp"
        after=$(wc -l < "$tmp")
        removed=$((before - after))
        if [ "$removed" -gt 0 ]; then
            chmod --reference="$HOME/.bashrc" "$tmp"
            mv "$tmp" "$HOME/.bashrc"
            count=$((count + removed))
        else
            rm -f "$tmp"
        fi
    fi

    # ── Shell completion (~/.bash_completion) — anchored source lines only ──
    if [ -f "$HOME/.bash_completion" ]; then
        local before after removed tmp
        before=$(wc -l < "$HOME/.bash_completion")
        tmp="$(mktemp)"
        awk '/^[[:space:]]*source[[:space:]].*pos\.bash/ { next } { print }' "$HOME/.bash_completion" > "$tmp"
        after=$(wc -l < "$tmp")
        removed=$((before - after))
        if [ "$removed" -gt 0 ]; then
            chmod --reference="$HOME/.bash_completion" "$tmp"
            mv "$tmp" "$HOME/.bash_completion"
            count=$((count + removed))
        else
            rm -f "$tmp"
        fi
    fi

    ok "Removed $count items (tier 1)"
}

remove_tier2() {
    local cfg="$HOME/.config/linux_post_install"
    local count=0

    if [ -d "$cfg" ]; then
        local f
        while IFS= read -r f; do
            rm -f "$f" && count=$((count+1))
        done < <(find "$cfg" -maxdepth 2 -type f 2>/dev/null)

        # Remove empty directory tree
        rmdir "$cfg/schedule.d" 2>/dev/null || true
        rmdir "$cfg" 2>/dev/null || true
    fi

    ok "Removed $count items (tier 2)"
}

remove_tier3() {
    local data="$HOME/.local/share/linux_post_install"
    local count=0

    if [ -d "$data" ]; then
        # Remove files first
        local f
        while IFS= read -r f; do
            rm -f "$f" && count=$((count+1))
        done < <(find "$data" -maxdepth 2 -type f 2>/dev/null)

        # Remove directories bottom-up
        while IFS= read -r d; do
            rmdir "$d" 2>/dev/null && count=$((count+1)) || true
        done < <(find "$data" -mindepth 1 -depth -type d 2>/dev/null)

        # Remove top-level directory if empty
        rmdir "$data" 2>/dev/null || true
    fi

    ok "Removed $count items (tier 3)"
}

# ── Main ────────────────────────────────────────────────────────
main() {
    section "pos system uninstall"

    # Scan all tiers
    local scan1 scan2 scan3
    scan1="$(scan_tier1)"
    scan2="$(scan_tier2)"
    scan3="$(scan_tier3)"

    # Display the plan
    display_plan "$scan1" "$scan2" "$scan3"

    # Nothing to do at all?
    if [ -z "$scan1" ] && [ -z "$scan2" ] && [ -z "$scan3" ]; then
        ok "Nothing to remove — pos toolkit does not appear to be installed."
        return 0
    fi

    # ── Tier 1: always remove (confirm unless --yes) ──
    if [ -n "$scan1" ]; then
        if [ "$YES_MODE" -eq 1 ]; then
            log "Removing tier 1 items (--yes)..."
        else
            confirm "Remove tier 1 items (binaries, services, shell integration)?" || return 0
        fi
        remove_tier1
    fi

    # ── Tier 2: config files ──
    if [ -n "$scan2" ]; then
        if [ "$DEL_CONFIG" -eq 0 ] && [ "$YES_MODE" -eq 0 ]; then
            confirm "Also remove config files (tier 2)?" && DEL_CONFIG=1 || true
        fi
        [ "$DEL_CONFIG" -eq 1 ] && remove_tier2
    fi

    # ── Tier 3: session/log data ──
    if [ -n "$scan3" ]; then
        if [ "$DEL_DATA" -eq 0 ] && [ "$YES_MODE" -eq 0 ]; then
            confirm "Also remove session/log data (tier 3)?" && DEL_DATA=1 || true
        fi
        [ "$DEL_DATA" -eq 1 ] && remove_tier3
    fi

    echo
    ok "Uninstall complete."
    echo "  The git repo was NOT removed — delete it manually if desired."
    echo "  Restart your shell or run: source ~/.bashrc"
}

main "$@"