#!/bin/sh
# diting installer — the one-liner entry point:
#   curl -fsSL https://raw.githubusercontent.com/yinnho/diting/main/install.sh | sh
#
# Downloads the release binary for the running OS/arch, verifies its sha256
# against the release-published checksum, installs to a bin dir, and finishes
# with `diting doctor` so a broken environment says so immediately.
#
# Env overrides (namespaced and legacy spellings both accepted):
#   DITING_VERSION / VERSION          pin a release (e.g. v0.9.0); default: latest
#   DITING_BIN_DIR / PREFIX           install target; default: /usr/local/bin
#                                           if writable, else ~/.local/bin
#   DITING_GH_PROXY                   prefix mirror for github.com downloads,
#                                           for networks where GitHub is slow/blocked
#                                           (e.g. https://ghfast.top/ — third-party)
set -eu

repo="yinnho/diting"
say() { printf '%s\n' "$*" >&2; }

# ---- platform → release target -------------------------------------------
os=$(uname -s)
arch=$(uname -m)
case "$os" in
    Darwin) vendor="apple-darwin" ;;
    Linux)  vendor="unknown-linux-gnu" ;;
    # git-bash / MSYS / Cygwin on Windows (uname -s is MINGW64_NT-... there)
    MINGW*|MSYS*|CYGWIN*) vendor="pc-windows-msvc" ;;
    *) say "unsupported OS: $os (macOS, Linux, and Windows git-bash only)"; exit 1 ;;
esac
case "$arch" in
    x86_64|amd64)  cpu="x86_64" ;;
    aarch64|arm64) cpu="aarch64" ;;
    *) say "unsupported arch: $arch"; exit 1 ;;
esac
target="${cpu}-${vendor}"
# Linux arm64 ships as one static musl build (no libc dependency).
if [ "$target" = "aarch64-unknown-linux-gnu" ]; then
    target="aarch64-unknown-linux-musl"
fi
case "$target" in
    aarch64-apple-darwin|x86_64-apple-darwin|x86_64-unknown-linux-gnu|x86_64-pc-windows-msvc|aarch64-unknown-linux-musl) ;;
    *) say "no prebuilt binary for $target"; exit 1 ;;
esac

# ---- version ---------------------------------------------------------------
version="${DITING_VERSION:-${VERSION:-}}"
if [ -z "$version" ]; then
    version=$(curl -fsSL --connect-timeout 10 "https://api.github.com/repos/$repo/releases/latest" \
        | sed -n 's/.*"tag_name": *"\(v[^"]*\)".*/\1/p' | head -1)
    [ -n "$version" ] || { say "could not resolve latest release (api.github.com unreachable?) — pin one: DITING_VERSION=v0.9.0 sh install.sh"; exit 1; }
fi
# The git tag carries the v, asset names never do (scripts/release_lib.sh).
version="v${version#v}"
asset="diting-${version#v}-${target}.tar.gz"
say ">> diting $version for $target"

# ---- download + verify -----------------------------------------------------
gh="https://github.com/$repo/releases/download/${version}"
base="${DITING_GH_PROXY:-}$gh"
tmp=$(mktemp -d)
trap 'rm -rf "$tmp"' EXIT
fetch() { curl -fsSL --retry 2 --connect-timeout 15 -o "$2" "$1"; }

if ! fetch "$base/$asset" "$tmp/$asset"; then
    say ""
    say "download failed from $gh"
    say "if GitHub is slow/blocked on your network, retry through a mirror:"
    say "  DITING_GH_PROXY=https://ghfast.top/ sh -c 'curl -fsSL <install-url> | sh'"
    say "(mirrors are third-party)"
    exit 1
fi
fetch "$base/$asset.sha256" "$tmp/$asset.sha256"

if command -v sha256sum >/dev/null 2>&1; then
    (cd "$tmp" && grep "  $asset\$" "$asset.sha256" | sha256sum -c -)
elif command -v shasum >/dev/null 2>&1; then
    want=$(awk '{print $1}' "$tmp/$asset.sha256")
    got=$(shasum -a 256 "$tmp/$asset" | awk '{print $1}')
    [ "$want" = "$got" ] || { say "sha256 mismatch: expected $want, got $got"; exit 1; }
else
    say ">> [warn] no sha256 tool found — skipping integrity check"
fi
say ">> sha256 ok"

# ---- install ---------------------------------------------------------------
bindir="${DITING_BIN_DIR:-${PREFIX:-}}"
if [ -z "$bindir" ]; then
    # git-bash /usr/local/bin lives inside the Git install dir and is not on
    # PATH — the per-user bin is the sane default there.
    if [ "$vendor" = "pc-windows-msvc" ]; then
        bindir="$HOME/.local/bin"
    elif [ -d /usr/local/bin ] && [ -w /usr/local/bin ]; then
        bindir=/usr/local/bin
    else
        bindir="$HOME/.local/bin"
    fi
fi
mkdir -p "$bindir"
# tarballs are one directory deep: diting-vX.Y.Z-target/diting[.exe]
bin=diting
if [ "$vendor" = "pc-windows-msvc" ]; then bin=diting.exe; fi
tar -xzf "$tmp/$asset" -C "$tmp"
src=$(find "$tmp" -mindepth 2 -maxdepth 2 -name "$bin" -type f | head -1)
[ -n "$src" ] || { say "binary not found inside $asset"; exit 1; }
install -m 0755 "$src" "$bindir/$bin" 2>/dev/null || { cp "$src" "$bindir/$bin" && chmod 0755 "$bindir/$bin"; }
say ">> installed: $bindir/$bin"

# ---- doctor ----------------------------------------------------------------
if "$bindir/$bin" doctor; then
    :
else
    say ">> installed, but doctor reported a problem above (often just egress"
    say "   being firewalled — set DITING_PROXY if you need a proxy)."
fi

say ""
say "    start a server:   $bindir/$bin                # HTTP API on 0.0.0.0:8089"
say "    try it:           curl -sS -X POST http://127.0.0.1:8089/fetch \\"
say "                         -H 'Content-Type: application/json' \\"
say "                         -d '{\"url\":\"https://example.com\"}'"
say "    guide: https://github.com/$repo/blob/main/SKILL.md"
case ":$PATH:" in
    *":$bindir:"*) ;;
    *) say ""
       say "    [note] $bindir is not on your PATH — add it to use 'diting' directly:"
       say "      echo 'export PATH=\"$bindir:\$PATH\"' >> ~/.zshrc  (or ~/.bashrc)" ;;
esac