feat: Add interactive configuration setup wizard

go.mod

@@ -5,8 +5,10 @@ go 1.25.3
 require (
 	github.com/adrg/xdg v0.5.3
 	github.com/charmbracelet/bubbletea v1.3.10
+	github.com/charmbracelet/huh v0.8.0
 	github.com/charmbracelet/lipgloss v1.1.1-0.20250404203927-76690c660834
 	github.com/earthboundkid/versioninfo/v2 v2.24.1
+	github.com/go-playground/validator/v10 v10.28.0
 	github.com/joho/godotenv v1.5.1
 	github.com/spf13/cobra v1.10.2
 	github.com/stretchr/testify v1.11.1
@@ -18,10 +20,12 @@ require (
 	github.com/atotto/clipboard v0.1.4 // indirect
 	github.com/aymanbagabas/go-osc52/v2 v2.0.1 // indirect
 	github.com/aymerick/douceur v0.2.0 // indirect
+	github.com/catppuccin/go v0.3.0 // indirect
 	github.com/charmbracelet/colorprofile v0.3.3 // indirect
 	github.com/charmbracelet/x/ansi v0.11.1 // indirect
 	github.com/charmbracelet/x/cellbuf v0.0.14 // indirect
 	github.com/charmbracelet/x/exp/slice v0.0.0-20251125134817-d85927d7854b // indirect
+	github.com/charmbracelet/x/exp/strings v0.0.0-20251114205511-64e30b5ee1c5 // indirect
 	github.com/charmbracelet/x/term v0.2.2 // indirect
 	github.com/clipperhouse/displaywidth v0.6.0 // indirect
 	github.com/clipperhouse/stringish v0.1.1 // indirect
@@ -30,18 +34,24 @@ require (
 	github.com/cockroachdb/redact v1.1.6 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/dlclark/regexp2 v1.11.5 // indirect
+	github.com/dustin/go-humanize v1.0.1 // indirect
 	github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f // indirect
+	github.com/gabriel-vasile/mimetype v1.4.11 // indirect
 	github.com/galactixx/ansiwalker v1.0.0 // indirect
 	github.com/getsentry/sentry-go v0.39.0 // indirect
+	github.com/go-playground/locales v0.14.1 // indirect
+	github.com/go-playground/universal-translator v0.18.1 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/gorilla/css v1.0.1 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/kr/pretty v0.3.1 // indirect
 	github.com/kr/text v0.2.0 // indirect
+	github.com/leodido/go-urn v1.4.0 // indirect
 	github.com/lucasb-eyer/go-colorful v1.3.0 // indirect
 	github.com/mattn/go-localereader v0.0.1 // indirect
 	github.com/mattn/go-runewidth v0.0.19 // indirect
 	github.com/microcosm-cc/bluemonday v1.0.27 // indirect
+	github.com/mitchellh/hashstructure/v2 v2.0.2 // indirect
 	github.com/muesli/ansi v0.0.0-20230316100256-276c6243b2f6 // indirect
 	github.com/muesli/cancelreader v0.2.2 // indirect
 	github.com/muesli/reflow v0.3.0 // indirect
@@ -67,7 +77,7 @@ require (
 	cloud.google.com/go v0.123.0 // indirect
 	cloud.google.com/go/auth v0.17.0 // indirect
 	cloud.google.com/go/compute/metadata v0.9.0 // indirect
-	github.com/charmbracelet/bubbles v0.21.0
+	github.com/charmbracelet/bubbles v0.21.1-0.20250623103423-23b8fd6302d7
 	github.com/charmbracelet/glamour v0.10.0
 	github.com/cockroachdb/errors v1.12.0
 	github.com/felixge/httpsnoop v1.0.4 // indirect

go.sum

@@ -18,30 +18,46 @@ github.com/atotto/clipboard v0.1.4 h1:EH0zSVneZPSuFR11BlR9YppQTVDbh5+16AmcJi4g1z
 github.com/atotto/clipboard v0.1.4/go.mod h1:ZY9tmq7sm5xIbd9bOK4onWV4S6X0u6GY7Vn0Yu86PYI=
 github.com/aymanbagabas/go-osc52/v2 v2.0.1 h1:HwpRHbFMcZLEVr42D4p7XBqjyuxQH5SMiErDT4WkJ2k=
 github.com/aymanbagabas/go-osc52/v2 v2.0.1/go.mod h1:uYgXzlJ7ZpABp8OJ+exZzJJhRNQ2ASbcXHWsFqH8hp8=
-github.com/aymanbagabas/go-udiff v0.2.0 h1:TK0fH4MteXUDspT88n8CKzvK0X9O2xu9yQjWpi6yML8=
-github.com/aymanbagabas/go-udiff v0.2.0/go.mod h1:RE4Ex0qsGkTAJoQdQQCA0uG+nAzJO/pI/QwceO5fgrA=
+github.com/aymanbagabas/go-udiff v0.3.1 h1:LV+qyBQ2pqe0u42ZsUEtPiCaUoqgA9gYRDs3vj1nolY=
+github.com/aymanbagabas/go-udiff v0.3.1/go.mod h1:G0fsKmG+P6ylD0r6N/KgQD/nWzgfnl8ZBcNLgcbrw8E=
 github.com/aymerick/douceur v0.2.0 h1:Mv+mAeH1Q+n9Fr+oyamOlAkUNPWPlA8PPGR0QAaYuPk=
 github.com/aymerick/douceur v0.2.0/go.mod h1:wlT5vV2O3h55X9m7iVYN0TBM0NH/MmbLnd30/FjWUq4=
-github.com/charmbracelet/bubbles v0.21.0 h1:9TdC97SdRVg/1aaXNVWfFH3nnLAwOXr8Fn6u6mfQdFs=
-github.com/charmbracelet/bubbles v0.21.0/go.mod h1:HF+v6QUR4HkEpz62dx7ym2xc71/KBHg+zKwJtMw+qtg=
+github.com/catppuccin/go v0.3.0 h1:d+0/YicIq+hSTo5oPuRi5kOpqkVA5tAsU6dNhvRu+aY=
+github.com/catppuccin/go v0.3.0/go.mod h1:8IHJuMGaUUjQM82qBrGNBv7LFq6JI3NnQCF6MOlZjpc=
+github.com/charmbracelet/bubbles v0.21.1-0.20250623103423-23b8fd6302d7 h1:JFgG/xnwFfbezlUnFMJy0nusZvytYysV4SCS2cYbvws=
+github.com/charmbracelet/bubbles v0.21.1-0.20250623103423-23b8fd6302d7/go.mod h1:ISC1gtLcVilLOf23wvTfoQuYbW2q0JevFxPfUzZ9Ybw=
 github.com/charmbracelet/bubbletea v1.3.10 h1:otUDHWMMzQSB0Pkc87rm691KZ3SWa4KUlvF9nRvCICw=
 github.com/charmbracelet/bubbletea v1.3.10/go.mod h1:ORQfo0fk8U+po9VaNvnV95UPWA1BitP1E0N6xJPlHr4=
 github.com/charmbracelet/colorprofile v0.3.3 h1:DjJzJtLP6/NZ8p7Cgjno0CKGr7wwRJGxWUwh2IyhfAI=
 github.com/charmbracelet/colorprofile v0.3.3/go.mod h1:nB1FugsAbzq284eJcjfah2nhdSLppN2NqvfotkfRYP4=
 github.com/charmbracelet/glamour v0.10.0 h1:MtZvfwsYCx8jEPFJm3rIBFIMZUfUJ765oX8V6kXldcY=
 github.com/charmbracelet/glamour v0.10.0/go.mod h1:f+uf+I/ChNmqo087elLnVdCiVgjSKWuXa/l6NU2ndYk=
+github.com/charmbracelet/huh v0.8.0 h1:Xz/Pm2h64cXQZn/Jvele4J3r7DDiqFCNIVteYukxDvY=
+github.com/charmbracelet/huh v0.8.0/go.mod h1:5YVc+SlZ1IhQALxRPpkGwwEKftN/+OlJlnJYlDRFqN4=
 github.com/charmbracelet/lipgloss v1.1.1-0.20250404203927-76690c660834 h1:ZR7e0ro+SZZiIZD7msJyA+NjkCNNavuiPBLgerbOziE=
 github.com/charmbracelet/lipgloss v1.1.1-0.20250404203927-76690c660834/go.mod h1:aKC/t2arECF6rNOnaKaVU6y4t4ZeHQzqfxedE/VkVhA=
 github.com/charmbracelet/x/ansi v0.11.1 h1:iXAC8SyMQDJgtcz9Jnw+HU8WMEctHzoTAETIeA3JXMk=
 github.com/charmbracelet/x/ansi v0.11.1/go.mod h1:M49wjzpIujwPceJ+t5w3qh2i87+HRtHohgb5iTyepL0=
 github.com/charmbracelet/x/cellbuf v0.0.14 h1:iUEMryGyFTelKW3THW4+FfPgi4fkmKnnaLOXuc+/Kj4=
 github.com/charmbracelet/x/cellbuf v0.0.14/go.mod h1:P447lJl49ywBbil/KjCk2HexGh4tEY9LH0/1QrZZ9rA=
+github.com/charmbracelet/x/conpty v0.1.0 h1:4zc8KaIcbiL4mghEON8D72agYtSeIgq8FSThSPQIb+U=
+github.com/charmbracelet/x/conpty v0.1.0/go.mod h1:rMFsDJoDwVmiYM10aD4bH2XiRgwI7NYJtQgl5yskjEQ=
+github.com/charmbracelet/x/errors v0.0.0-20240508181413-e8d8b6e2de86 h1:JSt3B+U9iqk37QUU2Rvb6DSBYRLtWqFqfxf8l5hOZUA=
+github.com/charmbracelet/x/errors v0.0.0-20240508181413-e8d8b6e2de86/go.mod h1:2P0UgXMEa6TsToMSuFqKFQR+fZTO9CNGUNokkPatT/0=
 github.com/charmbracelet/x/exp/golden v0.0.0-20241011142426-46044092ad91 h1:payRxjMjKgx2PaCWLZ4p3ro9y97+TVLZNaRZgJwSVDQ=
 github.com/charmbracelet/x/exp/golden v0.0.0-20241011142426-46044092ad91/go.mod h1:wDlXFlCrmJ8J+swcL/MnGUuYnqgQdW9rhSD61oNMb6U=
 github.com/charmbracelet/x/exp/slice v0.0.0-20251125134817-d85927d7854b h1:Qkvnopj8jOAKWzv697mdSe9zdrhCk8grDRR4Dkt1wCE=
 github.com/charmbracelet/x/exp/slice v0.0.0-20251125134817-d85927d7854b/go.mod h1:vqEfX6xzqW1pKKZUUiFOKg0OQ7bCh54Q2vR/tserrRA=
+github.com/charmbracelet/x/exp/strings v0.0.0-20251114205511-64e30b5ee1c5 h1:mV10jOm1+nkt6e23maPI/uYjjztZh/vUCaEPIku5RGI=
+github.com/charmbracelet/x/exp/strings v0.0.0-20251114205511-64e30b5ee1c5/go.mod h1:/ehtMPNh9K4odGFkqYJKpIYyePhdp1hLBRvyY4bWkH8=
 github.com/charmbracelet/x/term v0.2.2 h1:xVRT/S2ZcKdhhOuSP4t5cLi5o+JxklsoEObBSgfgZRk=
 github.com/charmbracelet/x/term v0.2.2/go.mod h1:kF8CY5RddLWrsgVwpw4kAa6TESp6EB5y3uxGLeCqzAI=
+github.com/charmbracelet/x/termios v0.1.1 h1:o3Q2bT8eqzGnGPOYheoYS8eEleT5ZVNYNy8JawjaNZY=
+github.com/charmbracelet/x/termios v0.1.1/go.mod h1:rB7fnv1TgOPOyyKRJ9o+AsTU/vK5WHJ2ivHeut/Pcwo=
+github.com/charmbracelet/x/xpty v0.1.2 h1:Pqmu4TEJ8KeA9uSkISKMU3f+C1F6OGBn8ABuGlqCbtI=
+github.com/charmbracelet/x/xpty v0.1.2/go.mod h1:XK2Z0id5rtLWcpeNiMYBccNNBrP2IJnzHI0Lq13Xzq4=
+github.com/clipperhouse/displaywidth v0.6.0 h1:k32vueaksef9WIKCNcoqRNyKbyvkvkysNYnAWz2fN4s=
+github.com/clipperhouse/displaywidth v0.6.0/go.mod h1:R+kHuzaYWFkTm7xoMmK1lFydbci4X2CicfbGstSGg0o=
 github.com/clipperhouse/displaywidth v0.6.0 h1:k32vueaksef9WIKCNcoqRNyKbyvkvkysNYnAWz2fN4s=
 github.com/clipperhouse/displaywidth v0.6.0/go.mod h1:R+kHuzaYWFkTm7xoMmK1lFydbci4X2CicfbGstSGg0o=
 github.com/clipperhouse/stringish v0.1.1 h1:+NSqMOr3GR6k1FdRhhnXrLfztGzuG+VuFDfatpWHKCs=
@@ -56,16 +72,22 @@ github.com/cockroachdb/redact v1.1.6 h1:zXJBwDZ84xJNlHl1rMyCojqyIxv+7YUpQiJLQ7n4
 github.com/cockroachdb/redact v1.1.6/go.mod h1:BVNblN9mBWFyMyqK1k3AAiSxhvhfK2oOZZ2lK+dpvRg=
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/creack/pty v1.1.24 h1:bJrF4RRfyJnbTJqzRLHzcGaZK1NeM5kTC9jGgovnR1s=
+github.com/creack/pty v1.1.24/go.mod h1:08sCNb52WyoAwi2QDyzUCTgcvVFhUzewun7wtTfvcwE=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dlclark/regexp2 v1.11.5 h1:Q/sSnsKerHeCkc/jSTNq1oCm7KiVgUMZRDUoRu0JQZQ=
 github.com/dlclark/regexp2 v1.11.5/go.mod h1:DHkYz0B9wPfa6wondMfaivmHpzrQ3v9q8cnmRbL6yW8=
+github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
+github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
 github.com/earthboundkid/versioninfo/v2 v2.24.1 h1:SJTMHaoUx3GzjjnUO1QzP3ZXK6Ee/nbWyCm58eY3oUg=
 github.com/earthboundkid/versioninfo/v2 v2.24.1/go.mod h1:VcWEooDEuyUJnMfbdTh0uFN4cfEIg+kHMuWB2CDCLjw=
 github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f h1:Y/CXytFA4m6baUTXGLOoWe4PQhGxaX0KpnayAqC48p4=
 github.com/erikgeiser/coninput v0.0.0-20211004153227-1c3628e74d0f/go.mod h1:vw97MGsxSvLiUE2X8qFplwetxpGLQrlU1Q9AUEIzCaM=
 github.com/felixge/httpsnoop v1.0.4 h1:NFTV2Zj1bL4mc9sqWACXbQFVBBg2W3GPvqp8/ESS2Wg=
 github.com/felixge/httpsnoop v1.0.4/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
+github.com/gabriel-vasile/mimetype v1.4.11 h1:AQvxbp830wPhHTqc1u7nzoLT+ZFxGY7emj5DR5DYFik=
+github.com/gabriel-vasile/mimetype v1.4.11/go.mod h1:d+9Oxyo1wTzWdyVUPMmXFvp4F9tea18J8ufA774AB3s=
 github.com/galactixx/ansiwalker v1.0.0 h1:NIx/IfMSh/5koZFyP4CaE7EjJ+IJKWbdYEQ4iHMFiDM=
 github.com/galactixx/ansiwalker v1.0.0/go.mod h1:4McdJoCX79IvMyM0R/l/1U7CrV9XAAVtLOkNXdRl2Ag=
 github.com/galactixx/stringwrap v1.0.4 h1:HMHCNpeUsniVvgjywmQrvJUOnbBpYWT1erIb4k8z7vc=
@@ -79,6 +101,14 @@ github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
 github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
 github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
 github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/go-playground/assert/v2 v2.2.0 h1:JvknZsQTYeFEAhQwI4qEt9cyV5ONwRHC+lYKSsYSR8s=
+github.com/go-playground/assert/v2 v2.2.0/go.mod h1:VDjEfimB/XKnb+ZQfWdccd7VUvScMdVu0Titje2rxJ4=
+github.com/go-playground/locales v0.14.1 h1:EWaQ/wswjilfKLTECiXz7Rh+3BjFhfDFKv/oXslEjJA=
+github.com/go-playground/locales v0.14.1/go.mod h1:hxrqLVvrK65+Rwrd5Fc6F2O76J/NuW9t0sjnWqG1slY=
+github.com/go-playground/universal-translator v0.18.1 h1:Bcnm0ZwsGyWbCzImXv+pAJnYK9S473LQFuzCbDbfSFY=
+github.com/go-playground/universal-translator v0.18.1/go.mod h1:xekY+UJKNuX9WP91TpwSH2VMlDf28Uj24BCp08ZFTUY=
+github.com/go-playground/validator/v10 v10.28.0 h1:Q7ibns33JjyW48gHkuFT91qX48KG0ktULL6FgHdG688=
+github.com/go-playground/validator/v10 v10.28.0/go.mod h1:GoI6I1SjPBh9p7ykNE/yj3fFYbyDOpwMn5KXd+m2hUU=
 github.com/gogo/protobuf v1.3.2 h1:Ov1cvc58UF3b5XjBnZv7+opcTcQFZebYjWzi34vdm4Q=
 github.com/gogo/protobuf v1.3.2/go.mod h1:P1XiOD3dCwIKUDQYPy72D8LYyHL2YPYrpS2s69NZV8Q=
 github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
@@ -109,6 +139,8 @@ github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/leodido/go-urn v1.4.0 h1:WT9HwE9SGECu3lg4d/dIA+jxlljEa1/ffXKmRjqdmIQ=
+github.com/leodido/go-urn v1.4.0/go.mod h1:bvxc+MVxLKB4z00jd1z+Dvzr47oO32F/QSNjSBOlFxI=
 github.com/lucasb-eyer/go-colorful v1.3.0 h1:2/yBRLdWBZKrf7gB40FoiKfAWYQ0lqNcbuQwVHXptag=
 github.com/lucasb-eyer/go-colorful v1.3.0/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
 github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
@@ -120,6 +152,8 @@ github.com/mattn/go-runewidth v0.0.19 h1:v++JhqYnZuu5jSKrk9RbgF5v4CGUjqRfBm05byF
 github.com/mattn/go-runewidth v0.0.19/go.mod h1:XBkDxAl56ILZc9knddidhrOlY5R/pDhgLpndooCuJAs=
 github.com/microcosm-cc/bluemonday v1.0.27 h1:MpEUotklkwCSLeH+Qdx1VJgNqLlpY2KXwXFM08ygZfk=
 github.com/microcosm-cc/bluemonday v1.0.27/go.mod h1:jFi9vgW+H7c3V0lb6nR74Ib/DIB5OBs92Dimizgw2cA=
+github.com/mitchellh/hashstructure/v2 v2.0.2 h1:vGKWl0YJqUNxE8d+h8f6NJLcCJrgbhC4NcD46KavDd4=
+github.com/mitchellh/hashstructure/v2 v2.0.2/go.mod h1:MG3aRVU/N29oo/V/IhBX8GR/zz4kQkprJgF2EVszyDE=
 github.com/muesli/ansi v0.0.0-20230316100256-276c6243b2f6 h1:ZK8zHtRHOkbHy6Mmr5D264iyp3TiX5OmNcI5cIARiQI=
 github.com/muesli/ansi v0.0.0-20230316100256-276c6243b2f6/go.mod h1:CJlz5H+gyd6CUWT45Oy4q24RdLyn7Md9Vj2/ldJBSIo=
 github.com/muesli/cancelreader v0.2.2 h1:3I4Kt4BQjOR54NavqnDogx/MIoWBFa0StPA8ELUXHmA=

internal/config/config.go

@@ -1,32 +1,33 @@
 package config
 
 import (
+	"bufio"
+	"bytes"
 	_ "embed"
+	"fmt"
+	"io/fs"
 	"os"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strings"
 
 	"github.com/adrg/xdg"
+	"github.com/cockroachdb/errors"
+	"github.com/go-playground/validator/v10"
 	"github.com/joho/godotenv"
 )
 
 //go:embed prompt.md
 var prompt string
 
-type GeminiConfig struct {
-	APIKey string
-	Model  string
-}
-
-type OpenAIConfig struct {
-	APIKey  string
-	Model   string
-	BaseURL string
-}
-
 type Config struct {
-	LLMProvider string
+	LLMProvider string `validate:"required,oneof=google openai llama.cpp test"`
+	APIKey      string `validate:"required_unless=LLMProvider test"`
+	Model       string `validate:"required_unless=LLMProvider test"`
+	BaseURL     string `validate:"required_if=LLMProvider llama.cpp"`
 	Prompt      string
-	Gemini      GeminiConfig
-	OpenAI      OpenAIConfig
+	validate    *validator.Validate
 }
 
 func Load() (*Config, error) {
@@ -43,28 +44,144 @@ func Load() (*Config, error) {
 	cfg := &Config{
 		LLMProvider: os.Getenv("LLM_PROVIDER"),
 		Prompt:      prompt,
-		Gemini: GeminiConfig{
-			APIKey: os.Getenv("GEMINI_API_KEY"),
-			Model:  os.Getenv("GEMINI_MODEL"),
-		},
-		OpenAI: OpenAIConfig{
-			APIKey:  os.Getenv("OPENAI_API_KEY"),
-			BaseURL: os.Getenv("OPENAI_BASE_URL"),
-			Model:   os.Getenv("OPENAI_MODEL"),
-		},
+		validate:    validator.New(),
 	}
 
 	if cfg.LLMProvider == "" {
 		cfg.LLMProvider = "google"
 	}
 
-	if cfg.Gemini.Model == "" {
-		cfg.Gemini.Model = "gemini-2.5-flash-preview-09-2025"
+	switch cfg.LLMProvider {
+	case "google":
+		cfg.APIKey = os.Getenv("GEMINI_API_KEY")
+		cfg.Model = os.Getenv("GEMINI_MODEL")
+		if cfg.Model == "" {
+			cfg.Model = "gemini-2.5-flash-preview-09-2025"
+		}
+	case "openai":
+		cfg.APIKey = os.Getenv("OPENAI_API_KEY")
+		cfg.Model = os.Getenv("OPENAI_MODEL")
+		if cfg.Model == "" {
+			cfg.Model = "gpt-4o"
+		}
+	case "llama.cpp":
+		cfg.APIKey = os.Getenv("LLAMACPP_API_KEY")
+		cfg.BaseURL = os.Getenv("LLAMACPP_BASE_URL")
+		cfg.Model = os.Getenv("LLAMACPP_MODEL")
 	}
 
-	if cfg.OpenAI.Model == "" {
-		cfg.OpenAI.Model = "gpt-4o"
+	return cfg, nil
+}
+
+func (cfg *Config) IsTestMode() bool {
+	return cfg.LLMProvider == "test"
+}
+
+func (cfg *Config) Validate() error {
+	return cfg.validate.Struct(cfg)
+}
+
+func (cfg *Config) Save() error {
+	configPath, err := xdg.ConfigFile("git-commit-summary/config.env")
+	if err != nil {
+		return err
 	}
 
-	return cfg, nil
+	switch cfg.LLMProvider {
+	case "google":
+		return updateProperties(configPath, map[string]string{
+			"LLM_PROVIDER":   "google",
+			"GEMINI_API_KEY": cfg.APIKey,
+			"GEMINI_MODEL":   cfg.Model,
+		})
+	case "openai":
+		return updateProperties(configPath, map[string]string{
+			"LLM_PROVIDER":   "openai",
+			"OPENAI_API_KEY": cfg.APIKey,
+			"OPENAI_MODEL":   cfg.Model,
+		})
+	case "llama.cpp":
+		return updateProperties(configPath, map[string]string{
+			"LLM_PROVIDER":      "llama.cpp",
+			"LLAMACPP_API_KEY":  cfg.APIKey,
+			"LLAMACPP_MODEL":    cfg.Model,
+			"LLAMACPP_BASE_URL": cfg.BaseURL,
+		})
+	case "test":
+		return updateProperties(configPath, map[string]string{
+			"LLM_PROVIDER": "test",
+		})
+	default:
+		return errors.Newf("unknown LLM provider: %s", cfg.LLMProvider)
+	}
+}
+
+func updateProperties(configPath string, props map[string]string) error {
+	// Read existing file if present.
+	original := []string{}
+	data, err := os.ReadFile(configPath)
+	if err == nil {
+		scanner := bufio.NewScanner(bytes.NewReader(data))
+		for scanner.Scan() {
+			original = append(original, scanner.Text())
+		}
+	} else if !errors.Is(err, fs.ErrNotExist) {
+		return err
+	}
+
+	updated := map[string]bool{}
+	out := make([]string, 0, len(original))
+
+	// Matches:
+	//   KEY="VALUE"
+	//   KEY=VALUE
+	// Captures:
+	//   1: KEY
+	//   2: VALUE (inside quotes or unquoted)
+	//   3: quote type = `"` or empty if unquoted
+	re := regexp.MustCompile(`^\s*([A-Za-z_][A-Za-z0-9_]*)=(?:"(.*)"|(.*))\s*$`)
+
+	for _, line := range original {
+		m := re.FindStringSubmatch(line)
+		if m == nil {
+			// Keep raw/unknown lines
+			out = append(out, line)
+			continue
+		}
+
+		key := m[1]
+		oldVal := m[2]
+
+		// Check if this key should be updated
+		if newVal, ok := props[key]; ok {
+			if oldVal != newVal {
+				out = append(out, "# "+line)
+			}
+			out = append(out, fmt.Sprintf(`%s="%s"`, key, newVal))
+			updated[key] = true
+		} else {
+			out = append(out, line)
+		}
+	}
+
+	// Append any keys in props missing from the file (default to quoted form)
+	var newKeys []string
+	for k := range props {
+		if !updated[k] {
+			newKeys = append(newKeys, k)
+		}
+	}
+	sort.Strings(newKeys)
+
+	for _, k := range newKeys {
+		out = append(out, fmt.Sprintf(`%s="%s"`, k, props[k]))
+	}
+
+	if err := os.MkdirAll(filepath.Dir(configPath), 0o755); err != nil {
+		return err
+	}
+
+	// Write new content
+	buf := strings.Join(out, "\n") + "\n"
+	return os.WriteFile(configPath, []byte(buf), 0o600)
 }