#!/usr/bin/env nix-shell
#!nix-shell --pure -i bash -p ripgrep sd jq git lix delta

export NIXPKGS_ALLOW_UNFREE=1
export NIXPKGS_ALLOW_INSECURE=1
export NIXPKGS_ALLOW_BROKEN=1

git restore .

test -s packages.json || ( set -x;
  time nix-env --extra-experimental-features no-url-literals --option system x86_64-linux -f ./. -qaP --json --meta --out-path --drv-path --show-trace --no-allow-import-from-derivation > packages.json
)

jq <packages.json 'to_entries[] | select(.value.meta.position==null|not) | "\(.key)\t\(.value.meta.position)"' -r |
    sed -e "s#\t$(realpath .)/#\t#" |
    sed -e 's#:\([0-9]*\)$#\t\1#' |
    tr '0123456789' '9876543210' | sort | tr '0123456789' '9876543210' |
    grep . |
    grep -iv haskell |
    grep -iv /top-level/ |
    grep -iv chicken |
    grep -iv build |
    grep -E '/(package|default)\.nix' |
    while read attrpath fname col; do
        grep -qE "(fetchgit|fetchFromGitHub)" "$fname" || continue
        grep -qF 'rev = "refs/tags/' "$fname" || continue

        echo "$attrpath"

        data1a="$(nix eval --impure  --expr 'with import ./. {}; { inherit ('"$attrpath"') meta drvPath; _outPath='"$attrpath"'.outPath; src = { inherit ('"$attrpath"'.src) drvPath; _outPath='"$attrpath"'.src.outPath; }; }' --json)"
        data1b="$(nix eval --impure  --expr 'with import ./. {}; { src = { inherit ('"$attrpath"'.src) rev tag; }; }' --json)"
        data1c="$(nix eval --impure  --expr 'with import ../../master {}; '"$attrpath"'.src.tag != null' --json)"
        test -n "$data1a" || continue
        test -n "$data1b" || continue
        test "$data1c" = "true" || continue

        # test if src builds
        #if ! nix-build . -A "$attrpath".src ; then
        #    continue # /shrug
        #fi

        # extract tag
        tag="$(grep -E '\brev = "refs/tags/(.*)";' "$fname" -o | cut -d'"' -f2 | cut -d/ -f3-)"

        test -n "$tag" || continue
        [[ $(wc -l <<<"$tag") -eq 1 ]] || continue

        (set -x
            # convert rev -> tag
            sd '\brev = "refs/tags/(.*)";'  'tag = "$1";'  "$fname"
            sd '\btag = "\$\{(.*)\}";'      'tag = $1;'    "$fname"

            # fix meta changelog (YAGNI)
            sd -F '/releases/tag/${self.src.rev}'        '/releases/tag/'"$tag"  "$fname"
            sd -F '/releases/tag/${src.rev}'             '/releases/tag/'"$tag"  "$fname"
            sd -F '/releases/tag/${finalAttrs.src.rev}'  '/releases/tag/'"$tag"  "$fname"

            # undo https://github.com/NixOS/nixpkgs/pull/338301
            sd -F '/releases/tag/${lib.removePrefix "refs/tags/" src.rev}'             '/releases/tag/'"$tag"  "$fname"
            sd -F '/releases/tag/${lib.removePrefix "refs/tags/" finalAttrs.src.rev}'  '/releases/tag/'"$tag"  "$fname"
            sd -F '/releases/tag/${lib.removePrefix "refs/tags/" self.src.rev}'        '/releases/tag/'"$tag"  "$fname"
        )

        data2a="$(nix eval --impure  --expr 'with import ./. {}; { inherit ('"$attrpath"') meta drvPath; _outPath='"$attrpath"'.outPath; src = { inherit ('"$attrpath"'.src) drvPath; _outPath='"$attrpath"'.src.outPath; }; }' --json)"
        data2b="$(nix eval --impure  --expr 'with import ./. {}; { src = { inherit ('"$attrpath"'.src) rev tag; }; }' --json)"

        if ! test "$data1a" = "$data2a"; then
            >&2 echo "meta or {,src.}{drvPath,outPath} changed"
            git diff | delta --paging=never
            diff -u <(echo $data1a) <(echo $data2a) | delta --paging=never
            (set -x; git restore "$fname")
            continue
        fi

        if test "$data1b" = "$data2b"; then
            >&2 echo "src.tag didn't change"
            diff -u <(echo $data1b) <(echo $data2b) | delta --paging=never
            git diff | delta --paging=never
            (set -x; git restore "$fname")
            continue
        fi

        # test if src build, this check the FOD hash
        # not needed since outPath and drvPath are unchanged
        #if ! nix-build . -A "$attrpath".src --check ; then
        #    >&2 echo "src doesn't build"
        #    git diff | delta --paging=never
        #    (set -x; git restore "$fname")
        #    continue
        #fi

        # stage
        (set -x;
            git add "$fname"
            # git commit -m "$attrpath: migrate fetchgit from rev to tag"
        )
    done


test -s packages2.json || ( set -x;
  time nix-env --extra-experimental-features no-url-literals --option system x86_64-linux -f ./. -qaP --json --meta --out-path --drv-path --show-trace --no-allow-import-from-derivation > packages2.json
)