#!/usr/bin/env bash
# lib/restore-state.sh — tracks restore step outcomes and accumulated errors.
#
# State file:  $SSR_STATE_DIR/restore-state   (key=value, one per line)
# Error log:   $SSR_STATE_DIR/restore-errors.log
#
# Step values: ok | warn | fail | skipped | pending

_ssr_rs_state_file() {
    printf '%s/restore-state' "${SSR_STATE_DIR:-$HOME/.local/state/ssr}"
}
_ssr_rs_error_file() {
    printf '%s/restore-errors.log' "${SSR_STATE_DIR:-$HOME/.local/state/ssr}"
}

# Initialise (or reset) the state file for a new restore run.
# $1 = brewfile path used for this run.
ssr::rs::init() {
    local brewfile="${1:-}"
    local state_dir="${SSR_STATE_DIR:-$HOME/.local/state/ssr}"
    ssr::ensure_dir "$state_dir"

    # Archive previous state so `ssr status restore` can show it even after a
    # new run starts.
    local sf; sf="$(_ssr_rs_state_file)"
    [[ -f "$sf" ]] && cp -f "$sf" "${sf}.prev" 2>/dev/null || true

    # Truncate error log for the new run.
    : > "$(_ssr_rs_error_file)"

    # Write fresh state header.
    printf 'started=%s\nbrewfile=%s\n' "$(ssr::ts)" "$brewfile" > "$sf"
}

# Set a key in the state file (upsert).
ssr::rs::set() {
    local key="$1" val="$2"
    local sf; sf="$(_ssr_rs_state_file)"
    local tmp; tmp="$(mktemp)"
    grep -v "^${key}=" "$sf" 2>/dev/null > "$tmp" || true
    printf '%s=%s\n' "$key" "$val" >> "$tmp"
    mv -f "$tmp" "$sf"
}

# Get a value from the state file (empty string if absent).
ssr::rs::get() {
    local key="$1"
    grep "^${key}=" "$(_ssr_rs_state_file)" 2>/dev/null | cut -d= -f2- || true
}

# Append a timestamped error line to the error log.
ssr::rs::error() {
    printf '[%s] %s\n' "$(ssr::ts)" "$1" >> "$(_ssr_rs_error_file)"
}

# Run a named restore step.
# Usage: ssr::rs::run <step_key> <description> <function> [args…]
#
# If --resume is active and the step is already 'ok', it is skipped.
# Exit code of the function is captured; non-zero sets step to 'warn' (not
# fatal) and logs the error. The outer script keeps running.
ssr::rs::run() {
    local key="$1" desc="$2"; shift 2
    local fn="$1"; shift

    # Resume: skip steps that already completed successfully.
    if [[ "${SSR_RESTORE_RESUME:-false}" == "true" ]]; then
        local prev; prev="$(ssr::rs::get "step_${key}")"
        if [[ "$prev" == "ok" ]]; then
            ssr::log "SKIP [$desc] (already completed in previous run)"
            return 0
        fi
    fi

    ssr::log "STEP [$desc]"
    ssr::rs::set "step_${key}" "running"

    local rc=0
    "$fn" "$@" || rc=$?

    if [[ $rc -eq 0 ]]; then
        ssr::rs::set "step_${key}" "ok"
    else
        ssr::rs::set "step_${key}" "warn:rc=$rc"
        ssr::rs::error "[$desc] exited rc=$rc"
        ssr::warn "[$desc] finished with errors (rc=$rc) — continuing restore"
    fi
}

# Print a formatted restore report to stdout.
ssr::rs::report() {
    local sf; sf="$(_ssr_rs_state_file)"
    local ef; ef="$(_ssr_rs_error_file)"

    if [[ ! -f "$sf" ]]; then
        printf 'No restore state found (%s).\n' "$sf"
        return 0
    fi

    local started brewfile
    started="$(grep '^started=' "$sf" | cut -d= -f2-)"
    brewfile="$(grep '^brewfile=' "$sf" | cut -d= -f2-)"

    printf '\n%s\n' "── Restore Report ──────────────────────────────"
    printf '  started  : %s\n' "${started:-unknown}"
    printf '  brewfile : %s\n' "${brewfile:-(unknown)}"
    printf '\n  Steps:\n'

    local -a step_keys=(brew_install brew_restore mackup_restore macos_defaults prefs_import)
    local -A step_labels=(
        [brew_install]="Homebrew install"
        [brew_restore]="Brew bundle install"
        [mackup_restore]="Mackup restore"
        [macos_defaults]="macOS defaults"
        [prefs_import]="Prefs snapshot import"
    )
    local key val icon
    for key in "${step_keys[@]}"; do
        val="$(grep "^step_${key}=" "$sf" 2>/dev/null | cut -d= -f2- || true)"
        case "$val" in
            ok)       icon="✓" ;;
            skipped)  icon="–" ;;
            warn*)    icon="⚠" ;;
            fail*)    icon="✗" ;;
            running)  icon="…" ;;
            *)        icon="?" ;;
        esac
        printf '    %s  %-28s %s\n' "$icon" "${step_labels[$key]}" "${val:-(not run)}"
    done

    if [[ -s "$ef" ]]; then
        printf '\n  Errors:\n'
        sed 's/^/    /' "$ef"
    else
        printf '\n  No errors recorded.\n'
    fi

    printf '%s\n\n' "────────────────────────────────────────────────"

    # Resume hint if any step failed.
    if grep -qE '^step_[^=]+=(warn|fail)' "$sf" 2>/dev/null; then
        printf '  To retry failed steps:  ssr restore --resume\n\n'
    fi
}