#!/usr/bin/env bash
#
# Usage: generate repo_path output_path
#
# Example: generate https://github.com/libgit2/libgit2 path_to_output
# to clone the repository from GitHub and produce documentation;
# the repo_path can also be a local path

set -eo pipefail

source_path=$(mktemp -d)
verbose=
force=

for var in "$@"; do
    if [ "${var}" == "--verbose" ]; then
        verbose=true
    elif [ "${var}" == "--force" ]; then
        force=true
    elif [ "${repo_path}" == "" ]; then
        repo_path="${var}"
    elif [ "${output_path}" == "" ]; then
        output_path="${var}"
    else
        repo_path=""
        output_path=""
    fi
done

if [ "${repo_path}" = "" -o "${output_path}" = "" ]; then
    echo "usage: $0 [--verbose] [--force] repo_path output_path" 1>&2
    exit 1
fi

function do_checkout {
    if [ "$1" = "" ]; then
        echo "usage: $0 source_path" 1>&2
        exit 1
    fi

    if [ "${verbose}" ]; then
        echo ":: Checking out source trees..."
        echo ""
    fi

    source_path=$1

    mkdir -p "${source_path}"
    git clone "${repo_path}" "${source_path}/main" --no-checkout
    ( cd "${source_path}/main" && git sparse-checkout set --no-cone 'include/*' )
    ( cd "${source_path}/main" && git read-tree origin/main )
    ( cd "${source_path}/main" && git checkout -- include )

    for tag in $(git --git-dir="${source_path}/main/.git" tag -l); do
        git --git-dir="${source_path}/main/.git" worktree add -f "${source_path}/${tag}" "${tag}" --no-checkout
        ( cd "${source_path}/${tag}" && git sparse-checkout set --no-cone 'include/*' )
        ( cd "${source_path}/${tag}" && git read-tree HEAD )

        if [ "${tag}" == "v0.1.0" ]; then
            ( cd "${source_path}/${tag}" && git checkout -- src/git )
        elif [ "${tag}" == "v0.2.0" -o "${tag}" == "v0.3.0" ]; then
            ( cd "${source_path}/${tag}" && git checkout -- src/git2 )
        else
            ( cd "${source_path}/${tag}" && git checkout -- include )
        fi
    done
}

do_checkout ${source_path}

if [ "${verbose}" ]; then
    echo ""
    echo ":: Generating raw API documentation..."
    echo ""
fi

for version in ${source_path}/*; do
    version=$(echo "${version}" | sed -e "s/.*\///")
    commit=$( cd "${source_path}/${version}" && git rev-parse HEAD )

    if [ -f "${output_path}/api/${version}.json" ]; then
        existing_commit=$(jq -r .info.commit < "${output_path}/api/${version}.json")

        if [ "${existing_commit}" == "${commit}" -a ! "${force}" ]; then
            if [ "${verbose}" ]; then
                echo "Raw API documentation for ${version} exists; skipping..."
            fi

            continue
        fi
    fi

    echo "Generating raw API documentation for ${version}..."
    mkdir -p "${output_path}/api"
    node ./api-generator.js "${source_path}/${version}" > "${output_path}/api/${version}.json"
done

if [ "${verbose}" ]; then
    echo ""
    echo ":: Generating HTML documentation..."
    echo ""
fi

search_options=""
docs_options=""
if [ "${verbose}" ]; then
    search_options="${search_options} --verbose"
    docs_options="${docs_options} --verbose"
fi
if [ "${force}" ]; then
    docs_options="${docs_options} --force"
fi

node ./search-generator.js ${search_options} "${output_path}/api" "${output_path}/search-index"
node ./docs-generator.js ${docs_options} --jekyll-layout default "${output_path}/api" "${output_path}/reference"