#!/bin/bash

# SPDX-FileCopyrightText: 2026 Matthew Fennell <matthew@fennell.dev>
#
# SPDX-License-Identifier: AGPL-3.0-or-later

set -eux
set -o pipefail

# Each file not in upstream sqlite was manually checked at this commit
known_safe_commit="d4560f1f808381e07b1f8673c51190c52bdca468"
day_before_known_safe_commit="2026-08-21"

working_dir=$(mktemp -d)
cd "${working_dir}"

table=$(curl --silent https://sqlite.org/download.html | grep -A 2 ^PRODUCT,VERSION,RELATIVE-URL,SIZE-IN-BYTES,SHA3-HASH | tail -n 2)
amalgamation=$(echo "${table}" | grep sqlite-amalgamation)
src=$(echo "${table}" | grep sqlite-src)

amalgamation_relative_url=$(echo "${amalgamation}" | cut -d , -f 3)
amalgamation_url="https://sqlite.org/${amalgamation_relative_url}"

src_relative_url=$(echo "${src}" | cut -d , -f 3)
src_url="https://sqlite.org/${src_relative_url}"

amalgamation_hash=$(echo "${amalgamation}" | cut -d , -f 5)
src_hash=$(echo "${src}" | cut -d , -f 5)

git clone --shallow-since "${day_before_known_safe_commit}" https://github.com/sbooth/CSQLite.git CSQLite

cp -r CSQLite csqlite-reference
mv CSQLite csqlite-new

cd "${working_dir}/csqlite-reference"
git checkout "${known_safe_commit}"
cd "${working_dir}"

curl "${amalgamation_url}" --output amalgamation.zip
curl "${src_url}" --output src.zip

amalgamation_calculated_hash=$(openssl dgst -sha3-256 amalgamation.zip | cut -d = -f 2 | sed 's/ //g')
src_calculated_hash=$(openssl dgst -sha3-256 src.zip | cut -d = -f 2 | sed 's/ //g')

if [[ "${amalgamation_calculated_hash}" != "${amalgamation_hash}" ]]; then
	echo "Calculated amalgamation hash ${amalgamation_calculated_hash} did not match with upstream ${amalgamation_hash}"
	exit 1
fi

if [[ "${src_calculated_hash}" != "${src_hash}" ]]; then
	echo "Calculated src hash ${src_calculated_hash} did not match with upstream ${src_hash}"
	exit 1
fi

unzip amalgamation.zip
unzip src.zip

mv sqlite-amalgamation-* amalgamation
mv sqlite-src-* src

# Compare files copied from upstream sqlite to the upstream versions
diff --unified --color amalgamation/sqlite3.c csqlite-new/Sources/CSQLite/sqlite3.c
diff --unified --color amalgamation/sqlite3.h csqlite-new/Sources/CSQLite/include/sqlite3.h
diff --unified --color src/ext/misc/decimal.c csqlite-new/Sources/CSQLite/decimal.c
diff --unified --color src/ext/misc/ieee754.c csqlite-new/Sources/CSQLite/ieee754.c
diff --unified --color src/ext/misc/series.c csqlite-new/Sources/CSQLite/series.c
diff --unified --color src/ext/misc/shathree.c csqlite-new/Sources/CSQLite/shathree.c
diff --unified --color src/ext/misc/uuid.c csqlite-new/Sources/CSQLite/uuid.c
diff --unified --color src/src/sqlite3ext.h csqlite-new/Sources/CSQLite/include/sqlite3ext.h

# Compare files not copied from upstream sqlite to known safe version
diff --unified --color csqlite-reference/.github/dependabot.yml csqlite-new/.github/dependabot.yml
diff --unified --color csqlite-reference/.github/workflows/swift.yml csqlite-new/.github/workflows/swift.yml
diff --unified --color csqlite-reference/.gitignore csqlite-new/.gitignore
diff --unified --color csqlite-reference/LICENSE.md csqlite-new/LICENSE.md
diff --unified --color csqlite-reference/Package.swift csqlite-new/Package.swift
diff --unified --color csqlite-reference/Package@swift-5.3.swift csqlite-new/Package@swift-5.3.swift
diff --unified --color csqlite-reference/README.md csqlite-new/README.md
diff --unified --color csqlite-reference/Sources/CSQLite/csqlite_shims.c csqlite-new/Sources/CSQLite/csqlite_shims.c
diff --unified --color csqlite-reference/Sources/CSQLite/include/csqlite_shims.h csqlite-new/Sources/CSQLite/include/csqlite_shims.h
diff --unified --color csqlite-reference/Sources/CSQLite/include/module.modulemap csqlite-new/Sources/CSQLite/include/module.modulemap
diff --unified --color csqlite-reference/Tests/CSQLiteTests/CSQLiteBasicTests.swift csqlite-new/Tests/CSQLiteTests/CSQLiteBasicTests.swift
diff --unified --color csqlite-reference/Tests/CSQLiteTests/CSQLiteExtensionTests.swift csqlite-new/Tests/CSQLiteTests/CSQLiteExtensionTests.swift
diff --unified --color csqlite-reference/Tests/CSQLiteTests/CSQLiteFeatureTests.swift csqlite-new/Tests/CSQLiteTests/CSQLiteFeatureTests.swift

# Compare directory structure, check for newly created files
cd "${working_dir}/csqlite-reference"
find . | sort > "${working_dir}/csqlite-reference.files"
cd "${working_dir}/csqlite-new"
find . | sort > "${working_dir}/csqlite-new.files"
cd "${working_dir}"
diff --unified --color csqlite-reference.files csqlite-new.files

echo "No differences found"