#!/usr/bin/env bash
# Risk Bundle Verification Script
# RISK-BUNDLE-69-002: CI/offline kit pipeline integration
#
# Usage: verify-bundle.sh <bundle-path> [--signature <sig-path>] [--strict] [--json]
#
# This script verifies a risk bundle for integrity and correctness.
# Exit codes:
#   0 - Bundle is valid
#   1 - Bundle is invalid or verification failed
#   2 - Input error (missing file, bad arguments)

set -euo pipefail

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

# Defaults
BUNDLE_PATH=""
SIGNATURE_PATH=""
STRICT_MODE=false
JSON_OUTPUT=false

# Parse arguments
while [[ $# -gt 0 ]]; do
    case $1 in
        --signature)
            SIGNATURE_PATH="$2"
            shift 2
            ;;
        --strict)
            STRICT_MODE=true
            shift
            ;;
        --json)
            JSON_OUTPUT=true
            shift
            ;;
        -h|--help)
            echo "Usage: verify-bundle.sh <bundle-path> [--signature <sig-path>] [--strict] [--json]"
            echo ""
            echo "Arguments:"
            echo "  <bundle-path>           Path to risk-bundle.tar.gz (required)"
            echo ""
            echo "Options:"
            echo "  --signature <sig-path>  Path to detached signature file"
            echo "  --strict                Fail on any warning (e.g., missing optional providers)"
            echo "  --json                  Output results as JSON"
            echo ""
            echo "Exit codes:"
            echo "  0 - Bundle is valid"
            echo "  1 - Bundle is invalid"
            echo "  2 - Input error"
            exit 0
            ;;
        -*)
            echo "Unknown option: $1"
            exit 2
            ;;
        *)
            if [[ -z "$BUNDLE_PATH" ]]; then
                BUNDLE_PATH="$1"
            else
                echo "Unexpected argument: $1"
                exit 2
            fi
            shift
            ;;
    esac
done

# Validate required arguments
if [[ -z "$BUNDLE_PATH" ]]; then
    echo "Error: bundle path is required"
    exit 2
fi

if [[ ! -f "$BUNDLE_PATH" ]]; then
    echo "Error: bundle not found: $BUNDLE_PATH"
    exit 2
fi

# Create temporary extraction directory
WORK_DIR=$(mktemp -d)
trap "rm -rf $WORK_DIR" EXIT

# Initialize result tracking
ERRORS=()
WARNINGS=()
BUNDLE_ID=""
BUNDLE_VERSION=""
PROVIDER_COUNT=0
MANDATORY_FOUND=false

log_error() {
    ERRORS+=("$1")
    if [[ "$JSON_OUTPUT" != "true" ]]; then
        echo "ERROR: $1" >&2
    fi
}

log_warning() {
    WARNINGS+=("$1")
    if [[ "$JSON_OUTPUT" != "true" ]]; then
        echo "WARNING: $1" >&2
    fi
}

log_info() {
    if [[ "$JSON_OUTPUT" != "true" ]]; then
        echo "$1"
    fi
}

log_info "=== Risk Bundle Verification ==="
log_info "Bundle: $BUNDLE_PATH"
log_info ""

# Step 1: Verify bundle can be extracted
log_info "=== Step 1: Extract bundle ==="
if ! tar -tzf "$BUNDLE_PATH" > /dev/null 2>&1; then
    log_error "Bundle is not a valid tar.gz archive"
    if [[ "$JSON_OUTPUT" == "true" ]]; then
        echo "{\"valid\": false, \"errors\": [\"Bundle is not a valid tar.gz archive\"]}"
    fi
    exit 1
fi

tar -xzf "$BUNDLE_PATH" -C "$WORK_DIR"
log_info "Bundle extracted successfully"

# Step 2: Check required structure
log_info ""
log_info "=== Step 2: Verify structure ==="

REQUIRED_FILES=(
    "manifests/provider-manifest.json"
)

for file in "${REQUIRED_FILES[@]}"; do
    if [[ ! -f "$WORK_DIR/$file" ]]; then
        log_error "Missing required file: $file"
    else
        log_info "Found: $file"
    fi
done

# Step 3: Parse and validate manifest
log_info ""
log_info "=== Step 3: Validate manifest ==="

MANIFEST_FILE="$WORK_DIR/manifests/provider-manifest.json"
if [[ -f "$MANIFEST_FILE" ]]; then
    # Extract manifest fields using basic parsing (portable)
    if command -v jq &> /dev/null; then
        BUNDLE_ID=$(jq -r '.bundleId // empty' "$MANIFEST_FILE")
        BUNDLE_VERSION=$(jq -r '.version // empty' "$MANIFEST_FILE")
        INPUTS_HASH=$(jq -r '.inputsHash // empty' "$MANIFEST_FILE")
        PROVIDER_COUNT=$(jq '.providers | length' "$MANIFEST_FILE")

        log_info "Bundle ID: $BUNDLE_ID"
        log_info "Version: $BUNDLE_VERSION"
        log_info "Inputs Hash: $INPUTS_HASH"
        log_info "Provider count: $PROVIDER_COUNT"
    else
        # Fallback to grep-based parsing
        BUNDLE_ID=$(grep -o '"bundleId"[[:space:]]*:[[:space:]]*"[^"]*"' "$MANIFEST_FILE" | cut -d'"' -f4 || echo "")
        log_info "Bundle ID: $BUNDLE_ID (jq not available - limited parsing)"
    fi

    # Validate required fields
    if [[ -z "$BUNDLE_ID" ]]; then
        log_error "Manifest missing bundleId"
    fi
else
    log_error "Manifest file not found"
fi

# Step 4: Verify provider files
log_info ""
log_info "=== Step 4: Verify provider files ==="

# Check for mandatory provider (cisa-kev)
CISA_KEV_FILE="$WORK_DIR/providers/cisa-kev/snapshot"
if [[ -f "$CISA_KEV_FILE" ]]; then
    log_info "Found mandatory provider: cisa-kev"
    MANDATORY_FOUND=true

    # Verify hash if jq is available
    if command -v jq &> /dev/null && [[ -f "$MANIFEST_FILE" ]]; then
        EXPECTED_HASH=$(jq -r '.providers[] | select(.providerId == "cisa-kev") | .digest' "$MANIFEST_FILE" | sed 's/sha256://')
        ACTUAL_HASH=$(sha256sum "$CISA_KEV_FILE" | cut -d' ' -f1)

        if [[ "$EXPECTED_HASH" == "$ACTUAL_HASH" ]]; then
            log_info "  Hash verified: $ACTUAL_HASH"
        else
            log_error "cisa-kev hash mismatch: expected $EXPECTED_HASH, got $ACTUAL_HASH"
        fi
    fi
else
    log_error "Missing mandatory provider: cisa-kev"
fi

# Check optional providers
EPSS_FILE="$WORK_DIR/providers/first-epss/snapshot"
if [[ -f "$EPSS_FILE" ]]; then
    log_info "Found optional provider: first-epss"

    if command -v jq &> /dev/null && [[ -f "$MANIFEST_FILE" ]]; then
        EXPECTED_HASH=$(jq -r '.providers[] | select(.providerId == "first-epss") | .digest' "$MANIFEST_FILE" | sed 's/sha256://')
        ACTUAL_HASH=$(sha256sum "$EPSS_FILE" | cut -d' ' -f1)

        if [[ "$EXPECTED_HASH" == "$ACTUAL_HASH" ]]; then
            log_info "  Hash verified: $ACTUAL_HASH"
        else
            log_error "first-epss hash mismatch: expected $EXPECTED_HASH, got $ACTUAL_HASH"
        fi
    fi
else
    log_warning "Optional provider not found: first-epss"
fi

OSV_FILE="$WORK_DIR/providers/osv/snapshot"
if [[ -f "$OSV_FILE" ]]; then
    log_info "Found optional provider: osv"
else
    log_warning "Optional provider not found: osv (this is OK unless --include-osv was specified)"
fi

# Step 5: Verify DSSE signature (if present)
log_info ""
log_info "=== Step 5: Check signatures ==="

DSSE_FILE="$WORK_DIR/signatures/provider-manifest.dsse"
if [[ -f "$DSSE_FILE" ]]; then
    log_info "Found manifest DSSE signature"

    # Basic DSSE structure check
    if command -v jq &> /dev/null; then
        PAYLOAD_TYPE=$(jq -r '.payloadType // empty' "$DSSE_FILE")
        SIG_COUNT=$(jq '.signatures | length' "$DSSE_FILE")

        if [[ "$PAYLOAD_TYPE" == "application/vnd.stellaops.risk-bundle.manifest+json" ]]; then
            log_info "  Payload type: $PAYLOAD_TYPE (valid)"
        else
            log_warning "Unexpected payload type: $PAYLOAD_TYPE"
        fi

        log_info "  Signature count: $SIG_COUNT"
    fi
else
    log_warning "No DSSE signature found"
fi

# Check detached bundle signature
if [[ -n "$SIGNATURE_PATH" ]]; then
    if [[ -f "$SIGNATURE_PATH" ]]; then
        log_info "Found detached bundle signature: $SIGNATURE_PATH"
        # TODO: Implement actual signature verification
    else
        log_error "Specified signature file not found: $SIGNATURE_PATH"
    fi
fi

# Step 6: Summarize results
log_info ""
log_info "=== Verification Summary ==="

ERROR_COUNT=${#ERRORS[@]}
WARNING_COUNT=${#WARNINGS[@]}

if [[ "$JSON_OUTPUT" == "true" ]]; then
    # Output JSON result
    ERRORS_JSON=$(printf '%s\n' "${ERRORS[@]}" | jq -R . | jq -s . 2>/dev/null || echo "[]")
    WARNINGS_JSON=$(printf '%s\n' "${WARNINGS[@]}" | jq -R . | jq -s . 2>/dev/null || echo "[]")

    cat <<EOF
{
  "valid": $([[ $ERROR_COUNT -eq 0 ]] && echo "true" || echo "false"),
  "bundleId": "$BUNDLE_ID",
  "version": "$BUNDLE_VERSION",
  "providerCount": $PROVIDER_COUNT,
  "mandatoryProviderFound": $MANDATORY_FOUND,
  "errorCount": $ERROR_COUNT,
  "warningCount": $WARNING_COUNT,
  "errors": $ERRORS_JSON,
  "warnings": $WARNINGS_JSON
}
EOF
else
    log_info "Bundle ID: $BUNDLE_ID"
    log_info "Errors: $ERROR_COUNT"
    log_info "Warnings: $WARNING_COUNT"

    if [[ $ERROR_COUNT -gt 0 ]]; then
        echo ""
        echo "Errors:"
        for err in "${ERRORS[@]}"; do
            echo "  - $err"
        done
    fi

    if [[ $WARNING_COUNT -gt 0 ]]; then
        echo ""
        echo "Warnings:"
        for warn in "${WARNINGS[@]}"; do
            echo "  - $warn"
        done
    fi
fi

# Determine exit code
if [[ $ERROR_COUNT -gt 0 ]]; then
    if [[ "$JSON_OUTPUT" != "true" ]]; then
        echo ""
        echo "RESULT: INVALID"
    fi
    exit 1
fi

if [[ "$STRICT_MODE" == "true" && $WARNING_COUNT -gt 0 ]]; then
    if [[ "$JSON_OUTPUT" != "true" ]]; then
        echo ""
        echo "RESULT: INVALID (strict mode - warnings treated as errors)"
    fi
    exit 1
fi

if [[ "$JSON_OUTPUT" != "true" ]]; then
    echo ""
    echo "RESULT: VALID"
fi
exit 0