#Requires -Version 5.1
<#
.SYNOPSIS
    Create the conda environment "mcm-toolkit".

.DESCRIPTION
    Three ways to build the environment, in order of preference:

    (default)  explicit package list, installed from the "defaults" channel.
               Needs internet. Measured on this machine: ~14.5 min, ~3 GB download.
    -FromYml   same, but driven by environment.yml (better for reproducing later).
    -CloneBase mirrors the whole base environment. NOTE: on conda 25.11 this is NOT
               a fast local copy -- conda replays base's full package list and
               downloads/installs it. Use it only when you want an exact copy of base.

    To work offline later, build the environment BEFORE the contest and keep the
    conda package cache (D:\anaconda\pkgs) intact.

    NOTE: this file is intentionally pure ASCII, UTF-8 without BOM, LF endings.
    Windows PowerShell 5.1 parses .ps1 as ANSI when there is no BOM, so non-ASCII
    characters (e.g. Chinese) turn into illegal bytes and cause syntax errors.

.PARAMETER Name
    conda environment name. Default: mcm-toolkit.

.PARAMETER FromYml
    Build from environment.yml instead of the inline package list.

.PARAMETER CloneBase
    Clone the base environment instead of installing a explicit package list.

.PARAMETER Force
    Remove and recreate the environment if it already exists.

.EXAMPLE
    .\scripts\setup-conda.ps1
    Create "mcm-toolkit" with the science stack (needs internet).

.EXAMPLE
    .\scripts\setup-conda.ps1 -FromYml -Force
    Rebuild from environment.yml.
#>
[CmdletBinding()]
param(
    [string]$Name = 'mcm-toolkit',
    [switch]$FromYml,
    [switch]$CloneBase,
    [switch]$Force
)

$ErrorActionPreference = 'Stop'
$repoRoot = Split-Path -Parent $PSScriptRoot

# Packages required by pyproject.toml's core deps plus the [ml] / [graph] /
# [symbolic] / [excel] / [dev] extras. SALib, pymoo and pyright are pip-only
# (see install after the conda step).
$packages = @(
    'python=3.13',
    'numpy', 'scipy', 'pandas', 'matplotlib',
    'scikit-learn', 'statsmodels',
    'networkx', 'sympy', 'openpyxl',
    'pytest', 'ruff',
    'pip'
)
$pipOnly = @('SALib', 'pymoo', 'pyright')

function Find-Conda {
    $candidates = @(
        "$env:USERPROFILE\anaconda3\Scripts\conda.exe",
        "$env:USERPROFILE\miniconda3\Scripts\conda.exe",
        'D:\anaconda\Scripts\conda.exe',
        'C:\ProgramData\Anaconda3\Scripts\conda.exe',
        'C:\ProgramData\miniconda3\Scripts\conda.exe'
    )
    foreach ($c in $candidates) { if (Test-Path -LiteralPath $c) { return $c } }
    $onPath = Get-Command conda -ErrorAction SilentlyContinue
    if ($onPath) { return $onPath.Source }
    throw 'conda not found. Install Anaconda/Miniconda first.'
}

$conda = Find-Conda
Write-Host "[1/5] conda = $conda"

# PITFALL: the Anaconda 25.x ToS plugin fetches channel metadata from
# repo.anaconda.com before every create/install and crashes when offline.
# This env var auto-accepts the ToS: it skips the network call while keeping
# the libmamba solver (unlike --no-plugins, which disables all plugins).
$env:CONDA_PLUGINS_AUTO_ACCEPT_TOS = 'yes'
$env:CONDA_AUTO_UPDATE_CONDA = 'false'

# PITFALL: envs_dirs and pkgs_dirs must be writable, otherwise conda fails with
# NotWritableError or "Error encountered while attempting to create cache directory".
Write-Host '[2/5] current envs_dirs / pkgs_dirs:'
& $conda config --show envs_dirs pkgs_dirs 2>$null | ForEach-Object { Write-Host "      $_" }

$existing = (& $conda env list --json | ConvertFrom-Json).envs |
    Where-Object { (Split-Path -Leaf $_) -eq $Name }
if ($existing) {
    if (-not $Force) {
        Write-Host "Environment '$Name' already exists ($existing). Use -Force to rebuild." -ForegroundColor Yellow
        exit 0
    }
    Write-Host "Environment '$Name' exists, -Force given, removing first ..."
    & $conda env remove -n $Name -y
}

Write-Host '[3/5] creating the environment (this can take 10-20 minutes) ...'
$sw = [Diagnostics.Stopwatch]::StartNew()
if ($FromYml) {
    $yml = Join-Path $repoRoot 'environment.yml'
    if (-not (Test-Path -LiteralPath $yml)) { throw "Not found: $yml" }
    & $conda env create -n $Name -f $yml
} elseif ($CloneBase) {
    & $conda create -n $Name --clone base -y
} else {
    & $conda create -n $Name -y @packages
}
if ($LASTEXITCODE -ne 0) { throw "conda create failed (exit code $LASTEXITCODE)" }
Write-Host ("      done in {0:N0}s" -f $sw.Elapsed.TotalSeconds)

$envPy = Join-Path (Split-Path -Parent (Split-Path -Parent $conda)) "envs\$Name\python.exe"
if (-not (Test-Path -LiteralPath $envPy)) {
    $envsRoot = (& $conda config --show envs_dirs | Select-String -Pattern '\S' | Select-Object -First 1).ToString().Trim()
    $envPy = Join-Path $envsRoot "$Name\python.exe"
}

Write-Host '[4/5] installing pip-only extras (SALib, pymoo, pyright) + this project ...'
& $envPy -m pip install --disable-pip-version-check --no-warn-script-location -q @pipOnly
& $envPy -m pip install -e $repoRoot --no-deps --no-build-isolation --disable-pip-version-check -q

Write-Host '[5/5] verifying ...'
& $envPy -c "import numpy, scipy, pandas, matplotlib, sklearn, statsmodels, networkx, sympy, SALib, pymoo, mcm_toolkit; print('  numpy', numpy.__version__, '| pandas', pandas.__version__, '| sklearn', sklearn.__version__); print('  mcm_toolkit', mcm_toolkit.__version__)"

Write-Host ''
Write-Host 'Done. Activate with:' -ForegroundColor Green
Write-Host "    conda activate $Name"