# Extension Version Resolution
# Resolves versions from OCI tags, Gitea releases, and local sources

use ../utils/logging.nu *
use ../oci/client.nu *

# Resolve version from version specification
export def resolve-version [
    extension_type: string
    extension_name: string
    version_spec: string
    source_type: string = "auto"
]: nothing -> string {
    match $source_type {
        "oci" => (resolve-oci-version $extension_type $extension_name $version_spec)
        "gitea" => (resolve-gitea-version $extension_type $extension_name $version_spec)
        "local" => "local"
        "auto" => {
            # Try OCI first, then Gitea, then local
            if (is-oci-available) {
                resolve-oci-version $extension_type $extension_name $version_spec
            } else if (is-gitea-available) {
                resolve-gitea-version $extension_type $extension_name $version_spec
            } else {
                "local"
            }
        }
        _ => $version_spec
    }
}

# Resolve version from OCI registry tags
export def resolve-oci-version [
    extension_type: string
    extension_name: string
    version_spec: string
]: nothing -> string {
    let result = (do {
        let config = (get-oci-config)
        let token = (load-oci-token $config.auth_token_path)

        # Get all available tags from OCI registry
        let tags = (oci-get-artifact-tags
            $config.registry
            $config.namespace
            $extension_name
            --auth-token $token
        )

        if ($tags | is-empty) {
            log-warn $"No tags found for ($extension_name) in OCI registry"
            return $version_spec
        }

        # Filter to valid semver tags
        let versions = ($tags
            | where ($it | is-semver)
            | sort-by-semver
        )

        if ($versions | is-empty) {
            log-warn $"No valid semver versions found for ($extension_name)"
            return ($tags | last)
        }

        # Resolve version spec
        match $version_spec {
            "*" | "latest" => {
                log-debug $"Resolved 'latest' to ($versions | last)"
                $versions | last
            }
            _ => {
                if ($version_spec | str starts-with "^") {
                    # Caret: compatible with version (same major)
                    resolve-caret-constraint $version_spec $versions
                } else if ($version_spec | str starts-with "~") {
                    # Tilde: approximately equivalent (same minor)
                    resolve-tilde-constraint $version_spec $versions
                } else if ($version_spec | str contains "-") {
                    # Range: version1-version2
                    resolve-range-constraint $version_spec $versions
                } else if ($version_spec | str contains ">") or ($version_spec | str contains "<") {
                    # Comparison operators
                    resolve-comparison-constraint $version_spec $versions
                } else {
                    # Exact version
                    if $version_spec in $versions {
                        $version_spec
                    } else {
                        log-warn $"Exact version ($version_spec) not found, using latest"
                        $versions | last
                    }
                }
            }
        }
    } | complete)

    if $result.exit_code == 0 {
        $result.stdout
    } else {
        log-error $"Failed to resolve OCI version: ($result.stderr)"
        $version_spec
    }
}

# Resolve version from Gitea releases
export def resolve-gitea-version [
    extension_type: string
    extension_name: string
    version_spec: string
]: nothing -> string {
    # TODO: Implement Gitea version resolution
    log-warn "Gitea version resolution not yet implemented"
    $version_spec
}

# Resolve caret constraint (^1.2.3 -> >=1.2.3 <2.0.0)
def resolve-caret-constraint [
    version_spec: string
    versions: list
]: nothing -> string {
    let version = ($version_spec | str replace "^" "" | str replace "v" "")
    let parts = ($version | split row ".")

    let major = ($parts | get 0 | into int)

    # Get all versions with same major
    let compatible = ($versions
        | where {|v|
            let v_clean = ($v | str replace "v" "")
            let v_parts = ($v_clean | split row ".")
            let v_major = ($v_parts | get 0 | into int)

            $v_major == $major and (compare-semver $v_clean $version) >= 0
        }
    )

    if ($compatible | is-empty) {
        log-warn $"No compatible versions found for ($version_spec)"
        $versions | last
    } else {
        $compatible | last
    }
}

# Resolve tilde constraint (~1.2.3 -> >=1.2.3 <1.3.0)
def resolve-tilde-constraint [
    version_spec: string
    versions: list
]: nothing -> string {
    let version = ($version_spec | str replace "~" "" | str replace "v" "")
    let parts = ($version | split row ".")

    let major = ($parts | get 0 | into int)
    let minor = ($parts | get 1 | into int)

    # Get all versions with same major.minor
    let compatible = ($versions
        | where {|v|
            let v_clean = ($v | str replace "v" "")
            let v_parts = ($v_clean | split row ".")
            let v_major = ($v_parts | get 0 | into int)
            let v_minor = ($v_parts | get 1 | into int)

            $v_major == $major and $v_minor == $minor and (compare-semver $v_clean $version) >= 0
        }
    )

    if ($compatible | is-empty) {
        log-warn $"No compatible versions found for ($version_spec)"
        $versions | last
    } else {
        $compatible | last
    }
}

# Resolve range constraint (1.2.3-1.5.0)
def resolve-range-constraint [
    version_spec: string
    versions: list
]: nothing -> string {
    let range_parts = ($version_spec | split row "-")
    let min_version = ($range_parts | get 0 | str trim | str replace "v" "")
    let max_version = ($range_parts | get 1 | str trim | str replace "v" "")

    let in_range = ($versions
        | where {|v|
            let v_clean = ($v | str replace "v" "")
            (compare-semver $v_clean $min_version) >= 0 and (compare-semver $v_clean $max_version) <= 0
        }
    )

    if ($in_range | is-empty) {
        log-warn $"No versions found in range ($version_spec)"
        $versions | last
    } else {
        $in_range | last
    }
}

# Resolve comparison constraint (>=1.2.3, <2.0.0, etc.)
def resolve-comparison-constraint [
    version_spec: string
    versions: list
]: nothing -> string {
    # TODO: Implement comparison operators
    log-warn "Comparison operators not yet implemented, using latest"
    $versions | last
}

# Check if string is valid semver
export def is-semver []: string -> bool {
    $in =~ '^v?\d+\.\d+\.\d+(-[a-zA-Z0-9.]+)?(\+[a-zA-Z0-9.]+)?$'
}

# Compare semver versions (-1 if a < b, 0 if equal, 1 if a > b)
export def compare-semver [a: string, b: string]: nothing -> int {
    let a_clean = ($a | str replace "v" "")
    let b_clean = ($b | str replace "v" "")

    # Split into parts
    let a_parts = ($a_clean | split row "-" | get 0 | split row ".")
    let b_parts = ($b_clean | split row "-" | get 0 | split row ".")

    # Compare major.minor.patch
    for i in 0..2 {
        let a_num = ($a_parts | get -o $i | default "0" | into int)
        let b_num = ($b_parts | get -o $i | default "0" | into int)

        if $a_num < $b_num {
            return (-1)
        } else if $a_num > $b_num {
            return 1
        }
    }

    # If base versions equal, check pre-release
    let a_prerelease = ($a_clean | split row "-" | get -o 1 | default "")
    let b_prerelease = ($b_clean | split row "-" | get -o 1 | default "")

    if ($a_prerelease | is-empty) and ($b_prerelease | is-not-empty) {
        return 1  # Release > pre-release
    } else if ($a_prerelease | is-not-empty) and ($b_prerelease | is-empty) {
        return (-1)  # Pre-release < release
    } else if ($a_prerelease | is-empty) and ($b_prerelease | is-empty) {
        return 0  # Both releases, equal
    } else {
        # Compare pre-release strings lexicographically
        if $a_prerelease < $b_prerelease {
            -1
        } else if $a_prerelease > $b_prerelease {
            1
        } else {
            0
        }
    }
}

# Sort versions by semver
export def sort-by-semver []: list -> list {
    $in | sort-by --custom {|a, b|
        compare-semver $a $b
    }
}

# Get latest version from list
export def get-latest-version [versions: list]: nothing -> string {
    $versions | where ($it | is-semver) | sort-by-semver | last
}

# Check if version satisfies constraint
export def satisfies-constraint [
    version: string
    constraint: string
]: nothing -> bool {
    match $constraint {
        "*" | "latest" => true
        _ => {
            if ($constraint | str starts-with "^") {
                satisfies-caret $version $constraint
            } else if ($constraint | str starts-with "~") {
                satisfies-tilde $version $constraint
            } else if ($constraint | str contains "-") {
                satisfies-range $version $constraint
            } else {
                # Exact match
                ($version | str replace "v" "") == ($constraint | str replace "v" "")
            }
        }
    }
}

# Check if version satisfies caret constraint
def satisfies-caret [version: string, constraint: string]: nothing -> bool {
    let version_clean = ($version | str replace "v" "")
    let constraint_clean = ($constraint | str replace "^" "" | str replace "v" "")

    let v_parts = ($version_clean | split row ".")
    let c_parts = ($constraint_clean | split row ".")

    let v_major = ($v_parts | get 0 | into int)
    let c_major = ($c_parts | get 0 | into int)

    $v_major == $c_major and (compare-semver $version_clean $constraint_clean) >= 0
}

# Check if version satisfies tilde constraint
def satisfies-tilde [version: string, constraint: string]: nothing -> bool {
    let version_clean = ($version | str replace "v" "")
    let constraint_clean = ($constraint | str replace "~" "" | str replace "v" "")

    let v_parts = ($version_clean | split row ".")
    let c_parts = ($constraint_clean | split row ".")

    let v_major = ($v_parts | get 0 | into int)
    let v_minor = ($v_parts | get 1 | into int)
    let c_major = ($c_parts | get 0 | into int)
    let c_minor = ($c_parts | get 1 | into int)

    $v_major == $c_major and $v_minor == $c_minor and (compare-semver $version_clean $constraint_clean) >= 0
}

# Check if version satisfies range constraint
def satisfies-range [version: string, constraint: string]: nothing -> bool {
    let version_clean = ($version | str replace "v" "")
    let range_parts = ($constraint | split row "-")
    let min = ($range_parts | get 0 | str trim | str replace "v" "")
    let max = ($range_parts | get 1 | str trim | str replace "v" "")

    (compare-semver $version_clean $min) >= 0 and (compare-semver $version_clean $max) <= 0
}

# Check if Gitea is available
def is-gitea-available []: nothing -> bool {
    # TODO: Implement Gitea availability check
    false
}